[Cover Illustration: JOHN W. CAMPBELL THE ULTIMATE WEAPON

 When star fights star, is chaos the best defense?]

RED SUN RISING

The star Mira was unpredictably variable. Sometimes it was blazing, brilliant and hot. Other times it was oddly dim, cool, shedding littlewarmth on its many planets. Gresth Gkae, leader of the Mirans, wasseeking a better star, one to which his "people" could migrate. Thatstar had to be steady, reliable, with a good planetary system. And inhis astronomical searching, he found Sol. 

With hundreds of ships, each larger than whole Terrestrial spaceports, and traveling faster than the speed of light, the Mirans set out to movein to Solar regions and take over. 

And on Earth there was nothing which would be capable of beating offthis incredible armada--until Buck Kendall stumbled upon THE ULTIMATEWEAPON. 

JOHN W. CAMPBELL first started writing in 1930 when his first shortstory, _When the Atoms Failed_, was accepted by a science-fictionmagazine. At that time he was twenty years old and still a student atcollege. As the title of the story indicates, he was even at that timeoccupied with the significance of atomic energy and nuclear physics. 

For the next seven years, Campbell, bolstered by a scientific backgroundthat ran from childhood experiments, to study at Duke University and theMassachusetts Institute of Technology, wrote and sold science-fiction, achieving for himself an enviable reputation in the field. 

In 1937 he became the editor of _Astounding Stories_ magazine andapplied himself at once to the task of bettering the magazine and thefield of s-f writing in general. His influence on science-fiction sincethen has been great. Today he still remains as the editor of thatmagazine's evolved and redesigned successor, _Analog_. 

 _THE ULTIMATE WEAPON_

 by JOHN W. CAMPBELL

 ACE BOOKS, INC. 1120 Avenue of the Americas New York, N. Y. 10036

THE ULTIMATE WEAPON

Copyright, 1936, by John W. Campbell

Originally published as a serial in _Amazing Stories_ under the title of_Uncertainty_. 

All Rights Reserved

_Cover by Gerald McConnell_

Printed in U. S. A. 

Transcriber's Note:

 Extensive research did not uncover any evidence that the U. S. Copyright on this publication was renewed. Minor spelling and typographical errors have been corrected without note. Subscript characters are shown within {braces}. The mathematical symbol pi is shown as [pi]. 

[Illustration]

I

Patrol Cruiser "IP-T 247" circling out toward Pluto on leisurelyinspection tour to visit the outpost miners there, was in no hurry atall as she loafed along. Her six-man crew was taking it very easy, andeasy meant two-man watches, and low speed, to watch for the instrumentpanel and attend ship into the bargain. 

She was about thirty million miles off Pluto, just beginning to get intouch with some of the larger mining stations out there, when BuckKendall's turn at the controls came along. Buck Kendall was one oflife's little jokes. When Nature made him, she was absentminded. Buckstood six feet two in his stocking feet, with his usual slight stoop inoperation. When he forgot, and stood up straight, he loomed about twoinches higher. He had the body and muscles of a dock navvy, which Naturestarted out to make. Then she forgot and added something of the samestuff she put in Sir Francis Drake. Maybe that made Old Nature nervous, and she started adding different things. At any rate, Kendall, asfinally turned out, had a brain that put him in the first rank ofscientists--when he felt like it--the general constitution of an ostrichand a flair for gambling. 

The present position was due to such a gamble. An IP man, a friend ofhis, had made the mistake of betting him a thousand dollars he wouldn'tget beyond a Captain's bars in the Patrol. Kendall had liked the ideaanyway, and adding a bit of a bet to it made it irresistible. So, beinga very particular kind of a fool, the glorious kind which old Natureturns out now and then, he left a five million dollar estate on LongIsland, Terra, that same evening, and joined up in the Patrol. The SirFrancis Drake strain had immediately come forth--and Kendall was havingthe time of his life. In a six-man cruiser, his real work in theInterplanetary Patrol had started. He was still in it--but it was hiscommand now, and a blue circle on his left sleeve gave his lieutenant'srank. 

Buck Kendall had immediately proceeded to enlist in his command the IPman who had made the mistaken bet, and Rad Cole was on duty with himnow. Cole was the technician of the T-247. His rank as TechnicalEngineer was practically equivalent to Kendall's circle-rank, which madethe two more comfortable together. 

Cole was listening carefully to the signals coming through from Pluto. "That, " he decided, "sounds like Tad Nichols' fist. You can recognizethat broken-down truck-horse trot of his on the key as far away as youcan hear it. "

"Is that what it is?" sighed Buck. "I thought it was static mushing himat first. What's he like?"

"Like all the other damn fools who come out two billion miles to scratchrock, as if there weren't enough already on the inner planets. He's gota rich platinum property. Sells ninety percent of his output to buy hispower, and the other eleven percent for his clothes and food. "

"He must be an efficient miner, " suggested Kendall, "to maintain 101%production like that. "

"No, but his bank account is. He's figured out that's the most economiclevel of production. If he produces less, he won't be able to pay forhis heating power, and if he produces more, his operation power willburn up his bank account too fast. "

"Hmmm--sensible way to figure. A man after my own heart. How does heplan to restock his bank account?"

"By mining on Mercury. He does it regularly--sort of a commuter. Outhere his power bills eat it up. On Mercury he goes in for potassium, andsells the power he collects in cooling his dome, of course. He's a goodminer, and the old fool can make money down there. " Like any reallyskilled operator, Cole had been sending Morse messages while he talked. Now he sat quiet waiting for the reply, glancing at the chronometer. 

"I take it he's not after money--just after fun, " suggested Buck. 

"Oh, no. He's after money, " replied Cole gravely. "You ask him--he'sgoing to make his eternal fortune yet by striking a real bed of jovium, and then he'll retire. "

"Oh, one of that kind. "

"They all are, " Cole laughed. "Eternal hope, and the rest of it. " Helistened a moment and went on. "But old Nichols is a first-gradeengineer. He wouldn't be able to remake that bankroll every time if hewasn't. You'll see his Dome out there on Pluto--it's always the best onthe planet. Tip-top shape. And he's a bit of an experimenter too. Ah--he's with us. "

Nichols' ragged signals were coming through--or pounding through. Theywere worse than usual, and at first Kendall and Cole couldn't make themout. Then finally they got them in bursts. The man was excited, and hisbad key-work made it worse. "--Randing stopped. They got him I think. Hesaid--th--ship as big--a--nsport. Said it wa--eaded my--ay. Neutrons--oninstruments--he's coming over the horizon--it's huge--war ship Ithink--register--instru--neutrons--. " Abruptly the signals were blankedout completely. 

 * * * * *

Cole and Kendall sat frozen and stiff. Each looked at the other abruptly, then Kendall moved. From the receiver, he ripped out the recording coil, and instantly jammed it into the analyzer. He started it through once, then again, then again, at different tone settings, till he found a veryshrill whine that seemed to clear up most of Nichols' bad key-work. "T-247--T-247--Emergency. Emergency. Randing reports the--over hishorizon. Huge--ip--reign manufacture. Almost spherical. Randing's stopped. They got him I think. He said the ship was as big as a transport. Saidit was headed my way. Neutrons--ont--gister--instruments. I think--ish--he's coming over the horizon. It's huge, and a war ship Ithink--register--instruments--neutrons. "

Kendall's finger stabbed out at a button. Instantly the noise of theother men, wakened abruptly by the mild shocks, came from behind. Kendall swung to the controls, and Cole raced back to the engine room. The hundred-foot ship shot suddenly forward under the thrust of her tailion-rockets. A blue-red cloud formed slowly behind her and expanded. Talbot appeared, and silently took her over from Kendall. "Stations, men, " snapped Kendall. "Emergency call from a miner of Pluto reporting alarge armed vessel which attacked them. " Kendall swung back, and easedhimself against the thrusting acceleration of the over-powered littleship, toward the engine room. Cole was bending over his apparatus, making careful check-ups, closing weapon-circuits. No window gave viewof space here; on the left was the tiny tender's pocket, on the right, above and below the great water tanks that fed the ion-rockets, behindthe rockets themselves. The tungsten metal walls were cold and grayunder the ship lights; the hunched bulks of the apparatus crowded thetiny room. Gigantic racked accumulators huddled in the corners. Martinand Garnet swung into position in the fighting-tanks just ahead of thepower rooms; Canning slid rapidly through the engine room, oozed througha tiny door, and took up his position in the stern-chamber, seatedhalf-over the great ion-rocket sheath. 

"Ready in positions, Captain Kendall, " called the war-pilot as thelittle green lights appeared on his board. 

"Test discharges on maximum, " ordered Kendall. He turned to Cole. "Youstart the automatic key?"

"Right, Captain. "

"All shipshape?"

"Right as can be. Accumulators at thirty-seven per cent, thanks to theloaf out here. They ought to pick up our signal back on Jupiter, he'snearest now. The station on Europa will get it. "

"Talbot--we are only to investigate if the ship is as reported. Have youseen any signs of her?"

"No sir, and the signals are blank. "

"I'll work from here. " Kendall took his position at the commandingcontrol. Cole made way for him, and moved to the power board. One by onehe tested the automatic doors, the pressure bulkheads. Kendall watchedthe instruments as one after another of the weapons were tested onmomentary full discharge--titanic flames of five million volt protons. Then the ship thudded to the chatter of the Garnell rifles. 

 * * * * *

Tensely the men watched the planet ahead, white, yet barely visible inthe weak sunlight so far out. It was swimming slowly nearer as the tinyship gathered speed. 

Kendall cast a glance over his detector-instruments. The radio networkwas undisturbed, the magnetic and electric fields recognized only theslight disturbances occasioned by the planet itself. There was nothing, noth--

Five hundred miles away, a gigantic ship came into instantaneous being. Simultaneously, and instantaneously, the various detector systems howledtheir warnings. Kendall gasped as the thing appeared on his view screen, with the scale-lines below. The scale must be cock-eyed. They said theship was fifteen hundred feet in diameter, and two thousand long!

"Retreat, " ordered Kendall, "at maximum acceleration. "

Talbot was already acting. The gyroscopes hummed in their castings, andthe motors creaked. The T-247 spun on her axis, and abruptly theacceleration built up as the ion-rockets began to shudder. A faint smellof "heat" began to creep out of the converter. Immense "weight" builtup, and pressed the men into their specially designed seats--

The gigantic ship across the way turned slowly, and seemed to stare atthe T-247. Then it darted toward them at incredible speed till the poorlittle T-247 seemed to be standing still, as sailors say. The strangerwas so gigantic now, the screens could not show all of him. 

"God, Buck--he's going to take us!"

Simultaneously, the T-247 rolled, and from her broke every possiblestream of destruction. The ion-rocket flames swirled abruptly towardher, the proton-guns whined their song of death in their housings, andthe heavy pounding shudder of the Garnell guns racked the ship. 

Strangely, Kendall suddenly noticed, there was a stillness in the ship. The guns and the rays were still going--but the little human soundsseemed abruptly gone. 

"Talbot--Garnet--" Only silence answered him. Cole looked across at himin sudden white-faced amazement. 

"They're gone--" gasped Cole. 

Kendall stood paralyzed for thirty seconds. Then suddenly he seemed tocome to life. "Neutrons! Neutrons--and water tanks! Old Nichols wasright--" He turned to his friend. "Cole--the tender--quick. " He darted aglance at the screen. The giant ship still lay alongside. A wash of ionswas curling around her, splitting, and passing on. The pinprickexplosions of the Garnell shells dotted space around her--but never onher. 

Cole was already racing for the tender lock. In an instant Kendall piledin after him. The tiny ship, scarcely ten feet long, was powered forflights of only two hours acceleration, and had oxygen for buttwenty-four hours for six men, seventy-two hours for two men--maybe. Theheavy door was slammed shut behind them, as Cole seated himself at thepanel. He depressed a lever, and a sudden smooth push shot them awayfrom the T-247. 

"DON'T!" called Kendall sharply as Cole reached for the ion-rocketcontrol. "Douse those lights!" The ship was dark in dark space. Thelighted hull of the T-247 drifted away from the little tender--furtherand further till the giant ship on the far side became visible. 

"Not a light--not a sign of fields in operation. " Kendall said, unconsciously speaking softly. "This thing is so tiny, that it mayescape their observation in the fields of the T-247 and Pluto downthere. It's our only hope. "

"What happened? How in the name of the planets did they kill those menwithout a sound, without a flash, and without even warning us, orinjuring us?"

"Neutrons--don't you see?"

"Frankly, I don't. I'm no scientist--merely a technician. Neutronsaren't used in any process I've run across. "

"Well, remember they're uncharged, tiny things. Small as protons, butwithout electric field. The result is they pass right through anordinary atom without being stopped unless they make a direct hit. Tungsten, while it has a beautifully high melting point, is mostly openspace, and a neutron just sails right through it, or any heavy atom. Light atoms stop neutrons better--there's less open space in 'em. Hydrogen is best. Well--a man is made up mostly of light elements, and aman stops those neutrons--it isn't surprising it killed those otherfellows invisibly, and without a sound. "

"You mean they bathed that ship in neutrons?"

"Shot it full of 'em. Just like our proton guns, only sending neutrons. "

"Well, why weren't we killed too?"

"'Water stops neutrons, ' I said. Figure it out. "

"The rocket-water tanks--all around us! Great masses of water--" gaspedCole. "That saved us?"

"Right. I wonder if they've spotted us. "

 * * * * *

The stranger ship was moving slowly in relation to the T-247. Suddenlythe motion changed, the stranger spun--and a giant lock appeared in herside, opened. The T-247 began to move, floated more and more rapidlystraight for the lock. Her various weapons had stopped operating now, the hoppers of the Garnell guns exhausted, the charge of theaccumulators aboard the ship down so low the proton guns had died out. 

"Lord--they're taking the whole ship!"

"Say--Cole, is that any ship you ever heard of before? _I don't thinkthat's just a pirate!_"

"Not a pirate--what then?"

"How'd he get inside our detector screens so fast? Watch--he'll eitherleave, or come after us--" The T-247 had settled inside the lock now, and the great metal door closed after it. The whole patrol ship had beenswallowed by a giant. Kendall was sketching swiftly on a notebook, watching the vast ship closely, putting down a record of its lines, andformation. He glanced up at it, and then down for a few more lines, andup at it--

The stranger ship abruptly dwindled. It dwindled with incredible speed, rushing off along the line of sight at an impossible velocity, andabruptly clicking out of sight, like an image on a movie-film that hasbeen cut, and repaired after the scene that showed the finaldisappearance. 

"Cole--Cole--did you get that? Did you see--do you understand whathappened?" Kendall was excitedly shouting now. 

"He missed us, " Cole sighed. "It's a wonder--hanging out here in space, with the protector of the T-247's fields gone. "

"No, no, you asteroid--that's not it. _He went off faster than lightitself!_"

"Eh--what? Faster than _light_? That can't be done--"

"He did it, I know he did. That's how he got inside our screens. He cameinside faster than the warning message could relay back the information. Didn't you see him accelerate to an impossible speed in an impossibletime? Didn't you see how he just vanished as he exceeded the speed oflight, and stopped reflecting it? _That ship was no ship of this solarsystem!_"

"Where did he come from then?"

"God only knows, but it's a long, long way off. "

II

The IP-M-122 picked them up. The M-122 got out there two days later, inresponse to the calls the T-247 had sent out. As soon as she got withinten million miles of the little tender, she began getting Cole'ssignals, and within twelve hours had reached the tiny thing, located it, and picked it up. 

Captain Jim Warren was in command, one of the old school commanders ofthe IP. He listened to Kendall's report, listened to Cole's tale--andradioed back a report of his own. Space pirates in a large ship hadattacked the T-247, he said, and carried it away. He advised a closewatch. On Pluto, his investigations disclosed nothing more than the factthat three mines had been raided, all platinum supplies taken, and therecords and machinery removed. 

 * * * * *

The M-122 was a fifty-man patrol cruiser, and Warren felt sure he couldhandle the menace alone, and hung around for over two weeks looking forit. He saw nothing, and no further reports came of attack. Again andagain, Kendall tried to convince him this ship he was hunting was nomere space pirate, and again and again Warren grunted, and went on hisway. He would not send in any report Kendall made out, because to do sowould add his endorsement to that report. He would not take Kendallback, though that was well within his authority. 

In fact, it was a full month before Kendall again set foot on any of theMinor Planets, and then it was Mars, the base of the M-122. Kendall andCole took passage immediately on an IP supply ship, and landed in NewYork six days later. At once, Kendall headed for Commander McLaurin'soffice. Buck Kendall, lieutenant of the IP, found he would have to makeregular application to see McLaurin through a dozen intermediateofficers. 

By this time, Kendall was savagely determined to see McLaurin himself, and see him in the least possible time. Cole, too, was beginning tobelieve in Kendall's assertion of the stranger ship's extra-systemicorigin. As yet neither could understand the strange actions of themachine, its attack on the Pluto mines, and the capture and theft of apatrol ship. 

"There is, " said Kendall angrily, "just one way to see McLaurin and seehim quick. And, by God, I'm going to. Will you resign with me, Cole?I'll see him within a week then, I'll bet. "

For a minute, Cole hesitated. Then he shook hands with his friends. "Today!" And that day it was. They resigned, together. Immediately, BuckKendall got the machinery in motion for an interview, working now fromthe outside, pulling the strings with the weight of a hundred milliondollar fortune. Even the IP officers had to pay a bit of attention whenBernard Kendall, multi-millionaire began talking and demanding things. Within a week, Kendall _did_ see McLaurin. 

At that time, McLaurin was fifty-three years old, his crisp hair stillblack as space, with scarcely a touch of the gray that appears in hismore recent photographs. He stood six feet tall, a broad-shouldered, powerful man, his face grave with lines of intelligence and character. There was also a permanent narrowing of the eyes, from years under theblazing sun of space. But most of all, while those years in space hadnarrowed and set his eyes, they had not narrowed and set his mind. Aninfinitely finer character than old Jim Warren, his experience in spacehad taught him always to expect the unexpected, to understand theincomprehensible as being part of the unknown and incalculableproperties of space and the worlds that swam in it. Besides the finetechnical education he had started with, he had acquired a liberaleducation in mankind. When Buck Kendall, straight and powerful, cameinto his office with Cole, he recognized in him a character that woulddrive steadily and straight for its goal. Also, he recognized behind themillionaire that had succeeded in pulling wires enough to see him, thescientist who had had more than one paper published "in an amateur way. "

"Dr. Bernard Kendall?" he asked, rising. 

"Yes, sir. Late Buck Kendall, lieutenant of the IP. I quit and got Colehere to quit with me, so we could see you. "

"Unusual tactics. I've had several men join up to get an interview withme. " McLaurin smiled. 

"Yes, I can imagine that, but we had to see you in a hurry. A hideboundold rapscallion by the name of Jim Warren picked us up out by Pluto, floating around in a six-man tender. We made some reports to him, but hewouldn't believe, and he wouldn't send them through--so we had to sendourselves through. Sir, this system is about to be attacked by someextra-systemic race. The IP-T-247 was so attacked, her crew killed off, and the ship itself carried away. "

"I got the report Captain Jim Warren sent through, stating it was a gangof space pirates. Now what makes you believe otherwise?"

"That ship that attacked us, attacked with a neutron gun, a gun thatshot neutrons through the hull of our ship as easily as protons passthrough open space. Those neutrons killed off four of the crew, andspared us only because we happened to be behind the water tanks. Massesof hydrogen will stop neutrons, so we lived, and escaped in the tender. The little tender, lightless, escaped their observation, and we werepicked up. Now, when the 247 had been picked up, and locked into theirship, that ship started accelerating. It accelerated so fast along myline of sight that it just dwindled, and--vanished. It didn't vanish indistance, it vanished _because it exceeded the speed of light_. "

"Isn't that impossible?"

"Not at all. It can be done--if you can find some way of escaping fromthis space to do it. Now if you could cut across through a higherdimension, your _projection_ in this dimension might easily exceed thespeed of light. For instance, if I could cut directly through the Earth, at a speed of one thousand miles an hour, my projection on the surfacewould go twelve thousand miles while I was going eight. Similar, if youcould cut _through_ the four dimensional space instead of following itssurface, you'd attain a speed greater than light. "

"Might it not still be a space pirate? That's a lot easier to believe, even allowing your statement that he exceeded the speed of light. "

"If you invented a neutron gun which could kill through tungsten wallswithout injuring anything within, a system of accelerating a ship thatdidn't affect the inhabitants of that ship, and a means of exceeding thespeed of light, all within a few months of each other, would you becomea pirate? I wouldn't, and I don't think any one else would. A pirate isa man who seeks adventure and relief from work. Given a means ofexceeding the speed of light, I'd get all the adventure I wantedinvestigating other planets. If I didn't have a cent before, I'd haverelief from work by selling it for a few hundred millions--and I'd sellit mighty easily too, for an invention like that is worth anincalculable sum. Tie to that the value of compensated acceleration, andno man's going to turn pirate. He can make more millions selling hisinventions than he can make thousands turning pirate with them. So who'dturn pirate?"

"Right. " McLaurin nodded. "I see your point. Now before I'd accept yourstatements _in re_ the 'speed of light' thing, I'd want opinions fromsome IP physicists. "

"Then let's have a conference, because something's got to be done soon. I don't know why we haven't heard further from that fellow. "

"Privately--we have, " McLaurin said in a slightly worried tone. "He wasdetected by the instruments of every IP observatory I suspect. We gotthe reports but didn't know what to make of them. They indicated so manyfunny things, they were sent in as accidental misreadings of theinstruments. But since _all_ the observatories reported them, similarmisreadings, at about the same times, that is with variations of only afew hours, we thought something must have been up. The only thing wasthe phenomena were reported progressively from Pluto to Neptune, clearacross the solar system, in a definite progression, but at a velocity ofcrossing that didn't tie in with any conceivable force. They crossedfaster than the velocity of light. That ship must have spent about halfan hour off each planet before passing on to the next. And, acceptingyour faster-than-light explanation, we can understand it. "

"Then I think you have proof. "

"If we have, what would you do about it?"

"Get to work on those 'misreadings' of the instruments for one thing, and for a second, and more important, line every IP ship with paraffinblocks six inches thick. "

"Paraffin--why?"

"The easiest form of hydrogen to get. You can't use solid hydrogen, because that melts too easily. Water can be turned into steam tooeasily, and requires more work. Paraffin is a solid that's largelyhydrogen. That's what they've always used on neutrons since theydiscovered them. Confine your paraffin between tungsten walls, andyou'll stop the secondary protons as well as the neutrons. "

"Hmmm--I suppose so. How about seeing those physicists?"

"I'd like to see them today, sir. The sooner you get started on thiswork, the better it will be for the IP. "

"Having seen me, will you join up in the IP again?" asked McLaurin. 

"No, sir, I don't think I will. I have another field you know, in whichI may be more useful. Cole here's a better technician than fighter--anda darned good fighter, too--and I think that an inexperiencedspace-captain is a lot less useful than a second-rate physicist at workin a laboratory. If we hope to get anywhere, or for that matter, Isuspect, stay anywhere, we'll have to do a lot of research prettypromptly. "

"What's your explanation of that ship?"

"One of two things: an inventor of some other system trying out hislatest toy, or an expedition sent out by a planetary government forexploration. I favor the latter for two reasons: that ship was _big_. Noinventor would build a thing that size, requiring a crew of severalhundred men to try out his invention. A government would build justabout that if they wanted to send out an expedition. If it were aninventor, he'd be interested in meeting other people, to see what theyhad in the way of science, and probably he'd want to do it in apeaceable way. That fellow wasn't interested in peace, by any means. SoI think it's a government ship, and an unfriendly government. They sentthat ship out either for scientific research, for trade research andexploration, or for acquisitive exploration. If they were out forscientific research, they'd proceed as would the inventor, to establishfriendly communication. If they were out for trade, the same wouldapply. If they were out for acquisitive exploration, they'd investigatethe planets, the sun, the people, only to the extent of learning howbest to overcome them. They'd want to get a sample of our people, and asample of our weapons. They'd want samples of our machinery, ourliterature and our technology. That's exactly what that ship got. 

"Somebody, somewhere out there in space, either doesn't like their home, or wants more home. They've been out looking for one. I'll bet they sentout hundreds of expeditions to thousands of nearby stars, graduallygoing further and further, seeking a planetary system. This is probablythe one and only one they found. It's a good one too. It has planets atall temperatures, of all sizes. It is a fairly compact one, it has astable sun that will last far longer than any race can hope to. "

"Hmm--how can there be good and bad planetary systems?" asked McLaurin. "I'd never thought of that. "

Kendall laughed. "Mighty easy. How'd you like to live on a planet of aCepheid Variable? Pleasant situation, with the radiation flaring up anddown. How'd you like to live on a planet of Antares? That blasted sunis so big, to have a comfortable planet you'd have to be at least tenbillion miles out. Then if you had an interplanetary commerce, you'dhave to struggle with orbits tens of billions of miles across instead ofmere millions. Further, you'd have a sun so blasted big, it would takean impossible amount of energy to lift the ship up from one planet toanother. If your trip was, say, twenty billions of miles to the nextplanet, you'd be fighting a gravity as bad as the solar gravity at Earthhere all the way--no decline with a little distance like that. "

"H-m-m-m--quite true. Then I should say that Mira would take the prize. It's a red giant, and it's an irregular variable. The sunlight therewould be as unstable as the weather in New England. It's almost as bigas Antares, and it won't hold still. Now that _would_ make a badplanetary system. "

"It would!" Kendall laughed. But as we know--he laughed too soon, and heshouldn't have used the conditional. He should have said, "It does!"

III

Gresth Gkae, Commander of Expeditionary Force 93, of the Planet Sthor, was returning homeward with joyful mind. In the lock of his great ship, lay the T-247. In her cargo holds lay various items of machinery, miningsupplies, foods, and records. And in her log books lay the records ofmany readings on the nine larger planets of a highly satisfactoryplanetary system. 

Gresth Gkae had spent no less than three ultra-wearing years going fromone sun to another in a definitely mapped out section of space. He hadinvestigated only eleven stars in that time, eleven stars, progressivelyfurther from the titanic red-flaming sun he knew as "the" sun. He knewit as "the" sun, and had several other appellations for it. Mira wasso-named by Earthmen because it was indeed a "wonder" star, in Latin, mirare means "to wonder. " Irregularly, and for no apparent reason itwould change its rate of radiation. So far as those inhabitants of Sthorand her sister world Asthor knew, there was no reason. It just did it. Perhaps with malicious intent to be annoying. If so, it wasexceptionally successful. Sthor and Asthor experienced, periodically, ayoung ice age. When Mira decided to take a rest, Sthor and Asthor frozeup, from the poles most of the way to the equators. Then Mira wouldstretch herself a little, move about restlessly and Sthor and Asthorwould become uninhabitably hot, anywhere within twenty degrees of theequator. 

Those Sthorian people had evolved in a way that made the conditionsendurable for savage or uncivilized people, but when a scientificcivilization with a well-ordered mode of existence tried to establishitself, Mira was all sorts of a nuisance. 

Gresth Gkae was a peculiar individual to human ways of thinking. Hestood some seven feet tall, on his strange, double-kneed legs and hisfour toed feet. His body was covered with little, short feather-likethings that moved now with a volition of their own. They were movingvery slowly and regularly. The space-ship was heated to a comfortabletemperature, and the little fans were helping to cool Gresth Gkae. Hadit been cold, every little feather would have lain down close againstits neighbors, forming an admirable, wind-proof and cold-proof blanket. 

Nature, on Sthor, had original ideas of arrangement too. Sthorianspossessed two eyes--one directly above the other, in the center of theirfaces. The face was so long, and narrow, it resembled a blunt hatchet, with the two eyes on the edge. To counter-balance this verticalarrangement of the eyes, the nostrils had been separated some fourinches, with one on each of the sloping cheeks. His ears were littlepink-flesh cups on short, muscular stems. His mouth was narrow, andsmall, but armed with quite solid teeth adapted to his diet, a dietconsisting of almost anything any creature had ever considered edible. Like most successful forms of intelligent life, Gresth Gkae wasomnivorous. An intelligent form of life is necessarily adaptable, andadaptation meant being able to eat what was at hand. 

One of his eyes, the upper one, was fully twice the size of the lowerone. This was his telescopic eye. The lower, or microscopic eye wasadapted to work for which a human being would have required a low powermicroscope, the upper eye possessed a more normal power of vision, _plus_ considerable telescopic powers. 

Gresth Gkae was using it now to look ahead in the blank of space towhere gigantic Mira appeared. On his screens now, Mira appeared deepviolet, for he was approaching at a speed greater than that of light, and even this projected light of Mira was badly distorted. 

"The distance is half a light-year now, sir, " reported the navigationofficer. 

"Reduce the speed, then, to normal velocity for these ranges. Whatreserve of fuel have we?"

"Less than one thousand pounds. We will barely be able to stop. We weretoo free in the use of our weapons, I fear, " replied the ChiefTechnician. 

"Well, what would you? We needed those things in our reports. Besides, we could extract fuel from that ore we took on at Planet Nine of Phahlo. It is merely that I wish speed in the return. "

"As we all do. How soon do you believe the Council will proceed againstthe new system?"

"It will be fully a year, I fear. They must gather the expeditionstogether, and re-equip the ships. It will be a long time before all willhave come in. "

"Could they not send fast ships after them to recall them?"

"Could they have traced us as we wove our way from Thart to Karst toRaloork to Phahlo? It would be impossible. "

 * * * * *

Steadily the great ship had been boring on her way. Mira had been a discfor nearly two days, gigantic, two-hundred-and-fifty-million-mile Miratook a great deal of dwarfing by distance to lose her disc. Even at theTwin Planets, eight thousand two hundred and fifty millions of milesout, Mira covered half the sky, it seemed, red and angry. Sometimes, though, to the disgust of the Sthorians it was just red-faced and lazy. Then Sthor froze. 

"Grih is in a descendant stage, " said the navigation officer presently. "Sthor will be cold when we arrive. "

"It will warm quickly enough with our news!" Gresth laughed. "Asystem--a delightful system--discovered. A system of many close-groupedplanets. Why think--from one side of that system to the other is less ofa distance than from Ansthat, our first planet's orbit, to Insthor'sorbit! That sun, as we know, is steady and warm. All will be well, whenwe have eliminated that rather peculiar race. Odd, that they should, insome ways, be so nearly like us! Nearly Sthorian in build. I would nothave expected it. Though they did have some amazing peculiarities!Imagine--two eyes just alike, and in a horizontal row. And that flatface. They looked as though they had suffered some accident that smashedthe front of the face in. And also the peculiar beak-like projection. Why should a race ever develop so amazing a projection in so peculiarand exposed a position? It sticks out inviting attack and injury. Rightin the middle of the face. And to make it worse, there is theair-channel, and the only air channel. Why, one minor injury to thethroat would be certain to damage that passage beyond repair, and bringdeath. Yet such relatively unimportant things as ears, and eyes aredoubled. Surely you would expect that so important a member as theair-passage would be doubled for safety. 

"Those strange, awkward arms and legs were what puzzled me. I have beenattempting to manipulate myself as they must be forced to, and I cannotsee how delicate or accurate manual manipulation would be possible withthose rigid, inflexible arms. In some ways I feel they must have hadclever minds to overcome so great a handicap to constructive work. But Isuppose single joints in the arms become as natural to them as our ownmore mobile two. 

"I wonder if life in any intelligent form wouldn't develop somewhatsimilar formations, though. Think, in all parts of Sthor, before menbecame civilized and developed communication, even so much as twentythousand years ago, our records show that seats and chairs were much asthey are today, and much as they are, in all places among all groups. Then too, the eye has developed in many different species, and alwaysreached much the same structure. When a thing is intended and developedto serve a given purpose, no matter who develops it, or where or how, isit not apt to have similar shapes and parts? A chair must have legs, anda seat and arm-rests and a back. You may vary their nature and theirshape, but not widely, and they must be there. An eye must, anywhere, have a sensitive retina, an adjustable lens, and an adjustable devicefor controlling the entrance of light. Similarly there are certainfunctions that the body of an intelligent creature must serve whichnaturally tend to make intelligent creatures similar. He must have atool--the hand--"

"Yes, yes--I see your point. It must be so, for surely these creaturesout there are strange enough in other ways. "

"But tell me, have you calculated when we shall land?"

"In twelve hours, thirty-three minutes, sir. "

Eleven hours later, the expedition ship had slowed to a normalspace-speed. On her left hung the giant globe of Asthor, rotatingslowly, moving slowly in her orbit. Directly ahead, Sthor loomed evengreater. Tiny Teelan, the thousand-mile diameter moon of the Insthorsystem shone dull red in the reflected light of gigantic Mira. Miraherself was gigantic, red and menacing across eight and a quarterbillions of miles of space. 

One hundred thousand miles apart, the twin worlds Sthor and Asthorrotated about their common center of gravity, eternally facing eachother. Ten million miles from their common center of gravity, Teelanrotated in a vast orbit. 

Sthor and Asthor were capped at each pole now by gigantic white icecaps. Mira was sulking, and as a consequence the planets were freezing. 

The expedition ship sank slowly toward Sthor. A swarm of smaller crafthad flown up at its approach to meet it. A gaily-colored small shipmarked the official greeting-ship. Gresth had withheld his newspurposely. Now suddenly he began broadcasting it from the powerfultransmitter on his ship. As the words came through on a thousand sets, all the little ships began to whirl, dance and break out into glowing, sparkling lights. On Sthor and Asthor even commotions began to bevisible. A new planetary system had been found-- They could move! Theiroverflowing populations could be spread out!

The whole Insthor system went mad with delight as the greatExpeditionary Ship settled downward. 

IV

There was a glint of humor in Buck Kendall's eyes as he passed the sheetover to McLaurin. Commander McLaurin looked down the columns withtwinkling eyes. 

"'Petition to establish the Lunar Mining Bank, '" he read. "What a bank!Officers: President, General James Logan, late of the IP;Vice-president, Colonel Warren Gerardhi, also late of the IP; Staff, consists of 90% ex-IP men, and a few scattered accountants. Designed bythe well-known designer of IP stations, Colonel Richard Murray. "Commander McLaurin looked up at Kendall with a broad grin. "And youactually got Interplanetary Life to give you a mortgage on thestructure?"

"Why not? It'll cut cost fifty-eight millions, with its twelve-foottungsten-beryllium walls and the heavy defense weapons against thoseterrible pirates. You know we must defend our property. "

"With the thing you're setting up out there on Luna, you could morereadily wipe out the IP than anything else I know of. Any new defenseideas?"

"Plenty. Did you get any further appropriations from the IPAppropriations Board?"

McLaurin looked sour. "No. The dear taxpayers might object, and thosethickheaded, clogged rockets on the Board can't see your data on theStranger. They gave me just ten millions, and that only because youdemonstrated you could shoot every living thing out of the latest IPcruiser with that neutron gun of yours. By the way, they may kick when Idon't install more than a few of those. "

"Let 'em. You can stall for a few months. You'll need that money morefor other purposes. You've installed that paraffin lining?"

"Yes--I got a report on that of 'finished' last week. How have you madeout?"

Buck Kendall's face fell. "Not so hot. Devin's been the biggest help--hedid most of the work on that neutron gun really--"

"After, " McLaurin interrupted, "you told him how. "

"--but we're pretty well stuck now, it seems. You'll be off dutytomorrow evening, can't you drop around to the lab? We're going to tryout a new system for releasing atomic energy. "

"Isn't that a pretty faint hope? We've been trying to get it for threecenturies now, and haven't yet. What chance at it within a year orso?--which is the time you allow yourself before the Stranger returns. "

"It is, I'll admit that. But there's another factor, not to beforgotten. The data we got from correlating those 'misreadings' from thevarious IP posts mean a lot. We are working on an entirely differenttrail now. You come on out, and you can see our new apparatus. They areworking on tremendous voltages, and hoping to smash the thing by abrutal bombardment of terrific voltage. We're trying, thanks to theresults of those instruments, to get results with small, terrificallyintense fields. "

"How do you know that's their general system?"

"They left traces on the records of the post instruments. These recordsshow such intensities as we never got. They have atomic energy, necessarily, and they might have had material energy, actual destructionof matter, but apparently, from the field readings it's the former. Tobe able to make those tremendous hops, light-years in length, theyneeded a real store of energy. They have accumulators, of course, but Idon't think they could store enough power by the system they use to doit. "

"Well, how's your trick 'bank' out on Luna, despite its twelve-footwalls, going to stand an atomic explosion?"

"More protective devices to come is our only hope. I'm working on threetrails: atomic energy, some type of magnetic shield that will stop anymoving material particle, and their faster-than-light thing. Also, thatfortress--I mean, of course, bank--is going to have a lot of lead-linedrooms. "

"I wish I could use the remaining money the Board gave me to lead-line alot of those IP ships, " said McLaurin wistfully. "Can't you make agamma-ray bomb of some sort?"

"Not without their atomic energy release. With it, of course, it's easyto flood a region with rays. It'll be a million times worse than radium'C, ' which is bad enough. "

"Well, I'll send through this petition for armaments. They'll pass itall right, I think. They may get some kicks from old Jacob Ezra Stubbs. Jacob Ezra doesn't believe in anything war-like. I wish they'd find someway to keep him off of the Arms Petition Board. He might just as wellstay home and let 'em vote his ticket uniformly 'nay. '" Buck Kendallleft with a laugh. 

 * * * * *

Buck Kendall had his troubles though. When he had reached Earth again, he found that his properties totaled one hundred and three milliondollars, roughly. One doesn't sell properties of that magnitude, oneborrows against them. But to all intents and purposes, Buck Kendallowned two half-completed ship's hulls in the Baldwin Spaceship Yards, agreat deal of massive metal work on its way to Luna, and contracts forsome very extensive work on a "bank. " Beyond that, about eleven millionwas left. 

A large portion of the money had been invested in a laboratory, the likeof which the world had never seen. It was devoted exclusively tophysics, and principally the physics of destruction. Dr. Paul Devin wasthe Director, Cole was in charge of the technical work, and Buck Kendallwas free to do all the work he thought needed doing. 

Returned to his laboratory, he looked sourly at the bench on which sevenmechanicians were working. The ninth successive experiment on therelease of atomic energy had failed. The tenth was in process ofconstruction. A heavy pure tungsten dome, three feet in diameter, threeinches thick, was being lowered over a clear insulum dome, a footsmaller. Inside, the real apparatus was arranged around the little poolof mercury. From it, two massive tungsten-copper alloy conductors ledthrough the insulum housing, and outside. These, so Kendall had hoped, would surge with the power of broken atoms, but he was beginning tobelieve rather bitterly, they would never do so. 

Buck went on to his offices, and the main calculator room. There wereten calculator tables here, two of them in operation now. 

"Hello, Devin. Getting on?"

"No, " said Devin bitterly, "I'm getting off. Look at these results. " Hebrought over a sheaf of graphs, with explanatory tables attached. Rapidly Buck ran through them with him. Most of them were graphs offunctions of light, considered as a wave in these experiments. 

"H-m-m-m--not very encouraging. Looks like you've got the field--but itjust snaps shut on itself and won't work. The lack of volume makes itbreak down, if you establish it, and makes it impossible to establish inthe first place without the energy of matter. Not so hot. That'scertainly cock-eyed somewhere. "

"I'm not. The math may be. "

"Well"--Kendall grinned--"it amounts to the same thing. The point is, light doesn't. Let's run over that theory again. Light is not onlymagnetic; but electric. Somehow it transforms electric fields cyclicallyinto magnetic fields and back again. Now what we want to do is totransform an electric into a magnetic field and have it stay there. That's the first step. The second thing, is to have the lines ofmagnetic force you develop, lie down like a sheath around the ship, instead of standing out like the hairs on an angry cat, the way theywant to. That means turning them ninety degrees, and turning an electricinto a magnetic field means turning the space-strain ninety degrees. Light evidently forms a magnetic field whose lines of force reach alongits direction of motion, so that's your starting point. "

"Yes, and _that_, " growled Devin, "seems to be the finishing point. Quite definitely and clearly, the graph looped down to zero. In otherwords, the field closed in on itself, and destroyed itself. "

"Light doesn't vanish. "

"I'll make you all the lights you want. "

"I simply mean there must be something that will stop it. "

"Certainly. Transform it back to electric field before it gets a chanceto close in, then repeat the process--the way light does. "

"That wouldn't make such a good magnetic shield. Every time that fieldstarted pulsing out through the walls of the ship it would generateheat. We want a permanent field that will stay on the job out there. Iwonder if you couldn't make a conductor device that would open thatfield out--some special type of oscillating field that would keep itopen. "

"H-m-m-m--that's an angle I might try. Any suggestions?"

Kendall had suggestions, and rapidly he outlined a development thatappeared from some of the earlier mathematics on light, and might bewhat they wanted. 

 * * * * *

Kendall, however, had problems of his own to work on. The question ofatomic energy he was leaving alone, till the present experiment eithersucceeded, or, as he rather suspected, failed as had its predecessors. His present problem was to develop more fully some interesting lines ofresearch he had run across in investigating mathematically the trick ofturning electric to magnetic fields and then turning them back again. Itmight be that along this line he would find the answer to the speedgreater than that of light. At any rate, he was interested. 

He worked the rest of that day, and most of the next on that line--tillhe ran it into the ground with a pair of equations that ended with theexpression: dx. Dv=h/(4[pi]m). Then Kendall looked at them for a longmoment, then he sighed gently and threw them into a file cabinet. Heisenberg's Uncertainty. He'd reduced the thing to a form that simplytold him it was beyond the limits of certainty and he ran it into thenormal, natural uncertainty inevitable in Nature. 

Anyway he had real work to do now. The machine was about ready for hisattention. The mechanicians had finished putting it in shape fordemonstration and trial. He himself would have to test it over the restof the afternoon and arrange for power and so forth. 

By evening, when Commander McLaurin called around with some of the otherinvestors in Kendall's "bank" on Luna, the thing was already started, warming up. The fields were being fed and the various scientists of thegroup were watching with interest. Power was flowing in already at arate of nearly one hundred thousand horsepower per minute, thanks to aspecial line given them by New York Power (a Kendall property). At teno'clock they were beginning to expect the reaction to start. By thistime the fields weren't gaining in intensity very rapidly, a maximumintensity had been reached that should, they felt, break the atoms soon. 

At eleven-thirty, through the little view window, Buck Kendall sawsomething that made him cry out in amazement. The mercury metal in thereceiver, behind its layers of screening was beginning to glow, with adull reddish light, and little solidifications were appearing in it!Eagerly the men looked, as the solidifications spread slowly, likecrystals growing in an evaporating solution. 

Twelve o'clock came and went, and one o'clock and two o'clock. Still theslow crystallization went on. Buck Kendall was casting furtive glancesat the kilowatt-hour meter. It stood at a figure that representedtwenty-seven thousand dollars' worth of power. Long since the power ratehad been increased to the maximum available, as the power plant's normalload reduced as the morning hours came. Surely, this time somethingwould start, but Buck had two worries. If all the enormous amount ofenergy they had poured in there decided to release itself at once--

And at any rate, Buck saw they'd never dare to let a generator stop, once it was started!

The men were a tense group around the machine at three-fifteen A. M. There remained only a tiny, dancing globule of silvery mercuryskittering around on the sharp, needle-like crystals of the dull redmetal that had resulted. Slowly that skittering drop was shrinking--

Three twenty-two and a half A. M. Saw the last fraction of it vanish. Tensely the men stared into the machine--backing off slowly--watchingthe meters on the board. At nearly eighty thousand volts the power hadbeen fed into it. 

The power continued to flow, and a growing halo of intense violet lightappeared suddenly on those red, needle-like crystals, a swiftlyexpanding halo--

Without a sound, without the slightest disturbance, the halo vanished, and softly, gently, the needle-like crystals relapsed, melted away, anda dull pool of metallic mercury rested in the receiver. 

At eighty thousand volts, power was flowing in--

And it didn't even sparkle. 

V

The apparatus of the magnetic shield had been completed two days later, and set up in Buck's own laboratory. On the bench was the powerful, butsmall, little projector of the straight magnetic field, simply aspecially designed accumulator, a super-condenser, and the peculiarapparatus Devin had designed to distort the electric field throughninety degrees to a magnetic field. Behind this was a curious, paraboloid projector made up of hundreds of tiny, carefully orientatedcoils. This was Buck's own contribution. They were ready for the tests. 

"I would invite McLaurin in to see this, " said Kendall looking at them, and then across the room bitterly toward the alleged atomic powerapparatus on the opposite bench. "I think it will work. But after_that_--" He stared, glaring, at the heavy tungsten dome with its heavytungsten contacts, across which the flame of released atomic energy wassupposed to have leapt. "That was probably the flattest flop anyexperiment ever flopped. "

"Well--it didn't blow up. That's one comfort, " suggested Devin. 

"I wish it had. Then at least it would have shown some response. Theonly response shown, actually, was shown on the power meter. It damnnear wore out the bearings turning so fast. "

"Personally, I prefer the lack of action. " Devin laughed. "Have you gotthat circuit hooked up?"

"Right, " sighed Kendall, turning back to the work in hand. "Is Douglassin on this?"

"Yes--in the next room. He'll let us know when he's ready. He's settingup those instruments. "

Douglass, a young junior physicist, late of the IP Physics Department, stuck his head in the door and announced his instruments were all setup. 

"Keep an eye on them. They'll move somehow, at any rate. This thingcouldn't go as flat as that atom-buster of mine. "

Carefully Kendall made a few last-minute adjustments on the limitingrelays, and took up his position at the power board. Devin took hisplace near the apparatus, with another series of instruments, similar tothose Douglass was now watching in the next room, some thirty feet away, through the two-inch metal wall. "Ready, " called Kendall. 

The switch shot home. Instantly Kendall, Devin, and all the men in thebuilding jumped some six feet from their former positions. A monstrousroar of sound crashed out in that laboratory that thundered from onewall to the other, and bellowed in a Titan's fury. It thundered andgrowled, it bellowed and howled, the walls shook with the march andcounter-march of crashing waves of sound. 

And a ten-foot wavering flame of blue-white, bellying electric fireshuddered up to the ceiling from the contact points of the allegedatomic generator. The heat, pouring out from the flashing, roaring arcsent prickles of aching burns over Kendall's skin. For ten seconds hestood in utter, paralyzed surprise as his flop of flops bellowed itsanger at his disdain. Then he leapt to the power board and shut off theroaring thing, by cutting the switch that had started it. 

"Spirits of Space! Did _that_ come to life!"

"_Atomic Energy!_" Devin cried. 

"Atomic energy, hell. That's my thirty thousand dollars' worth of powerbreaking loose again, " chortled Kendall. "We missed the atomic energy, but, sweet boy, what an accumulator we stubbed our toes on! I wonderedwhere in blazes all that power went to. That's the answer. I'll bet Ican tell you right now what happened. We built that mercury up to a newlevel, and that transitional stage was the red, crystalline metal. Whenit reached the higher stage, it was temporarily stable--but thatprojector over there that we designed for the purpose of holding openelectric and magnetic fields just opened the door and let all that powerright out again. "

"But why isn't it atomic energy? How do you know that no more than yourpower that you put in is coming out?" demanded Devin. 

"The arc, man, the arc. That was a high-current, and low-voltage arc. Couldn't you tell by the sound that no great voltage--as atomic voltagesgo--was smashing across there? If we were getting atomic voltage--andpower--there'd have been a different tone to it, high and shriller. 

"Now, did you take any readings?"

"What do you think, man? I'm human. Do you think I got any readings withthat thing bellowing and shrieking in my ears, and burning my skin withultra-violet? It itches now. "

Kendall laughed. "You know what to do for an itch. Now, I'm going tomake a bet. We had those points separated for a half-million voltsdischarge, but there was a dust-cover thrown over them just now. That, you notice, is missing. I'll bet that served as a starter lead for themain arc. Now I'm going to start that projector thing again, and movethe points there through about six inches, and that thing probably won'tstart itself. "

 * * * * *

Most of the laboratory staff had collected at the doorway, looking in atthe white-hot tungsten discharge points, and the now silent "atomicengine. " Kendall turned to them and said: "The flop picked itself up. You go on back, we seem to be all in one piece yet. Douglass, you didn'tget any readings, did you?"

Sheepishly, Douglass grinned at him. "Eh--er--no--but I tore my pants. The magnetic field grabbed me and I jumped. They had some steel buttons, and a lot of steel keys--they're kinda' hard to keep on now. "

The laboratory staff broke into a roar of laughter, as Douglass, holdingup his trousers with both hands was beheld. 

"I guess the field worked, " he said. 

"I guess maybe it did, " adjudged Kendall solemnly. "We have some ropehere if you need it--"

Douglass returned to his post. 

Swiftly, Kendall altered the atomic distortion storage apparatus, andreturned to the power-board. "Ready?"

"Check. "

Kendall shoved home the switch. The storage device was silent. Only aslight feeling of strain made itself felt, and the sudden noisy hum of asmall transformer nearby. "She works, Buck!" Devin called. "The readingscheck almost exactly. "

"All good then. Now I want to get to that atomic thing. We can let thatslide for a little bit--I'll answer it. "

The telephone had rung noisily. "Kendall Labs--Kendall speaking. "

"This is Superintendent Foster, of the New York Power, Mr. Kendall. Wehave some trouble just now that we think your operations may beresponsible for. The sub-station at North Beaumont blew all the fuses, and threw the breakers at the main station. The men out there said thetransformers began howling--"

"Right you are--I'm afraid I did do that. I had no idea that it wouldreach so far. How far is that from my place here?"

"It's about a thousand yards, according to the survey maps. "

"Thanks--and I'll be careful about it. Any damage, I am responsible for?All okay?"

"Yes, sir, Mr. Kendall. "

Kendall hung up. "We stirred up a lot more dustthan we expected, Devin. Now let's start seeing if we can keep track ofit. Douglass, how did your readings show?"

"I took them at the ten stations, and here they are. The stations aretwo feet apart. "

"H-m-m--. 5--. 55--. 6--. 7--20--198--5950--6010--6012--5920. Very, verynice--only the darned thing's got an arm as long as the law. Yourreadings were about . 2, Devin?"

"That's right. "

"Then these little readings are just leakage. What's our normalintensity here?"

"About . 19. Just a very small fraction less than the readings. "

"Perfect--we have what amounts to a hollow shell of magnetic force--wecan move inside, and you can move outside--far enough. But you can't geta conductor or a magnetic field through it. " He put the readings on thebench, and looked at the apparatus across the room. "Now I want to startright on that other. Douglass, you move that magnetostat apparatus outof the way, and leave just the 'can-opener' of ours--the projector. I'mpretty sure that's what does the deed. Devin, see if you can hunt upsome electrostatic voltmeters with a range in the neighborhood of--Ithink it'll be about eighty thousand. "

 * * * * *

Rapidly, Douglass was dismounting the apparatus, as Devin started forthe stock room. Kendall started making some new connections, reconnecting the apparatus they had intended using on the "atomicengine, " largely high-capacity resistances. He seemed to perform thiswork mechanically, his mind definitely on something else. Suddenly hestopped, and looked carefully into the receiver of the machine. Themetal in it was silvery, liquid, and here and there a floating crystalof the dull red metal. Slowly a smile spread across his face. He turnedto Douglass. 

"Douglass--ah, you're through. Get on the trail of MacBride, and get himand his crew to work making half a dozen smaller things like this. Tell'em they can leave off the tungsten shield. I want different metals inthe receiver of each. Use--hmmm--sodium--copper--magnesium--aluminium, iron and chromium. Got it?"

"Yes, sir. " He left, just as Devin returned with a large electrostaticvoltmeter. 

"I'd like, " said he, "to know how you know the voltage will range aroundeighty thousand. "

"K-ring excitation potential for mercury. I'm willing to bet that thingsimply shoved the whole electron system of the mercury out a notch--thatit simply _hasn't_ any K-ring of electrons now. I'm trying some othermetals. Douglass is going to have MacBride make up half a dozen moremachines. Machines--they need a name. This--ah--this is an 'atostor. 'MacBride's going to make up half a dozen of 'em, and try half a dozenmetals. I'm almost certain that's not mercury in there now, at all. It'sprobably element 99 or something like it. "

"It looks like mercury--"

"Certainly. So would 99. Following the periodic table, 99 would probablyhave an even lower melting point than mercury, be silvery, dense andheavy--and perhaps slightly radioactive. The series under the B familyof Group II is Magnesium, Zinc, Cadmium, Mercury--and 99. The meltingpoint is going down all the way, and they're all silvery metals. I'mgoing to try copper, and I fully expect it to turn silvery--in fact, tobecome silver. "

"Then let's see. " Swiftly they hooked up the apparatus, realigned theprojector, and again Kendall took his place at the power-board. As heclosed the switch, on no-load, the electrostatic voltmeter flopped overinstantly, and steadied at just over 80, 000 volts. 

"I hate to say 'I told you so, '" said Kendall. "But let's hook in aload. Try it on about 100 amps first. "

Devin began cutting in load. The resistors began heating up swiftly asmore and more current flowed through them. By not so much as by avibration of the voltmeter needle, did the apparatus betray any strainas the load mounted swiftly. 100--200--500--1000 amperes. Still, thatneedle held steady. Finally, with a drain of ten thousand amperes, allthe equipment available could handle, the needle was steady as a rock, though the tremendous load of 800, 000, 000 watts was cut in and out. That, to atoms, atoms by the nonillions, was no appreciable load at all. There was _no_ internal resistance whatever. The perfect accumulatorhad certainly been discovered. 

"I'll have to call McLaurin--" Kendall hurried away with a broad, broadsmile. 

VI

"Hello, Tom?"

The telephone rattled in a peeved sort of way. "Yes, it is. What now?And when am I going to see you in a social sort of way again?"

"Not for a long, long time; I'm busy. I'm busy right now as a matter offact. I'm calling up the vice-president of Faragaut InterplanetaryLines, and I want to place an order. "

"Why bother me? We have clerks, you know, for that sort of thing, "suggested Faragaut in a pained voice. 

"Tom, do you know how much I'm worth now?"

"Not much, " replied Faragaut promptly. "What of it? I hear, as a matterof fact that you're worth even less in a business way. They're talkingquite a lot down this way about an alleged bank you're setting up onLuna. I hear it's got more protective devices, and armor than any IPstation in the System, that you even had it designed by an IP designer, and have a gang of Colonels and Generals in charge. I also hear thatyou've succeeded in getting rid of money at about one million dollars aday--just slightly shy of that. "

"You overestimate me, my friend. Much of that is merely contracted for. Actually it'll take me nearly nine months to get rid of it. And by thattime I'll have more. Anyway, I think I have something like ten millionleft. And remember that way back in the twentieth century some oldfellow beat my record. Armour, I think it was, lost a million dollars aday for a couple of months running. 

"Anyway, what I called you up for was to say I'd like to order fivehundred thousand tons of mercury, for delivery as soon as possible. "

"What! Oh, say, I thought you were going in for business. " Faragaut gavea slight laugh of relief. 

"Tom, I am. I mean exactly what I say. I wantfive--hundred--thousand--_tons_ of metallic mercury, and just as soon asyou can get it. "

"Man, there isn't that much in the system. "

"I know it. Get all there is on the market for me, and contract to takeall the 'Jupiter Heavy-Metals' can turn out. You send those ordersthrough, and clean out the market completely. Somebody's about to payfor the work I've been doing, and boy, they're going to pay through thenose. After you've got that order launched, and don't make a christeningparty of the launching either, why just drop out here, and I'll show youwhy the value of mercury is going so high you won't be able to follow itin a space ship. "

"The cost of that, " said Faragaut, seriously now, "will beabout--fifty-three million at the market price. You'd have to put uptwenty-six cash, and I don't believe you've got it. "

Buck laughed. "Tom, loan me a dozen million, will you? You send thatorder through, and then come see what I've got. I've got a break, too!Mercury's the best metal for this use--and it'll stop gamma rays too!"

"So it will--but for the love of the system, what of it?"

"Come and see--tonight. Will you send that order through?"

"I will, Buck. I hope you're right. Cash is tight now, and I'll probablyhave to put up nearer twenty million, when all that buying goes through. How long will it be tied up in that deal, do you think?"

"Not over three weeks. And I'll guarantee you three hundred percent--ifyou'll stay in with me after you start. Otherwise--I don't think makingthis money would be fair just now. "

"I'll be out to see you in about two hours, Buck. Where are you? At theestate?" asked Faragaut seriously. 

"In my lab out there. Thanks, Tom. "

McLaurin was there when Tom Faragaut arrived. And General Logan, andColonel Gerardhi. There was a restrained air of gratefulness about allof them that Tom Faragaut couldn't quite understand. He had been lookingup Buck Kendall's famous bank, and more and more he had begun to wonderjust what was up. The list of stockholders had read like a list of IPheroes and executives. The staff had been a list of IP men with aslender sprinkling of accountants. And the sixty-million dollarstructure was to be a bank without advertising of any sort! Usually sucha venture is planned and published months in advance. This had sprung upsuddenly, with a strange quietness. 

Almost silently, Buck Kendall led the way to the laboratory. A smallmetal tank was supported in a peculiar piece of apparatus, and from itled a small platinum pipe to a domed apparatus made largely of insulum. A little pool of mercury, with small red crystals floating in it restedin a shallow hollow surrounded by heavy conductors. 

"That's it, Tom. I wanted to show you first what we have, and why Iwanted all that mercury. Within three weeks, every man, woman and childin the system will be clamoring for mercury metal. That's the perfectaccumulator. " Quickly he demonstrated the machine, charging it, and thendischarging it. It was better than 99. 95% efficient on the charge, andwas 100% efficient on the discharge. 

"Physically, any metal will do. Technically, mercury is best for anumber of reasons. It's a liquid. I can, and do it in this, charge acertain quantity, and then move it up to the storage tank. Chargeanother pool, and move it up. In discharge, I can let a stream flow incontinuously if I required a steady, terrific drain of power withoutinterruption. If I wanted it for more normal service, I'd discharge apool, drain it, refill the receiver, and discharge a second pool. Thus, mercury is the metal to use. 

"Do you see why I wanted all that metal?"

"I do, Buck--Lord, I do, " gasped Faragaut. "That is the perfect powersupply. "

"No, confound it, it isn't. It's a secondary source. It isn't primary. We're just as limited in the _supply_ of power as ever--only we haveincreased our distribution of power. Lord knows, we're going to need apower _supply_ badly enough before long--" Buck relapsed into moodysilence. 

"What, " asked Faragaut, looking around him, "does that mean?"

It was McLaurin who told him of the stranger ship, and Kendall'sinterpretation of its meaning. Slowly Faragaut grasped the meaningbehind Buck's strange actions of the past months. 

"The Lunar Bank, " he said slowly, half to himself. "Staffed by trainedIP men, experts in expert destruction. Buck, you said something aboutthe profits of this venture. What did you mean?"

Buck smiled. "We're going to stick up IP to the extent necessary to payfor that fort--er--bank--on Luna. We'll also boost the price so thatwe'll make enough to pay for those ships I'm having made. The publicwill pay for that. "

"I see. And we aren't to stick the price too high, and just make money?"

"That's the general idea. "

"The IP Appropriations Board won't give you what you need, Commander, for real improvements on the IP ships?"

"They won't believe Kendall. Therefore they won't. "

"What did you mean about gamma rays, Buck?"

"Mercury will stop them and the Commander here intends to have therefitted ships built so that the engine room and control room are one, and completely surrounded by the mercury tanks. The men will beprotected against the gamma rays. "

"Won't the rays affect the power stored in the mercury--perhaps releaseit?"

"We tried it out, of course, and while we can't get the intensities weexpect, and can't really make any measurements of the gamma-ray energyimpinging on the mercury--it seems to absorb, and store that energy!"

"What's next on the program, Buck?"

"Finish those ships I have building. And I want to do some moredevelopment work. The Stranger will return within six months now, Ibelieve. It will take all that time, and more for real refitting of theIP ships. "

"How about more forts--or banks, whichever you want to call them. Marsisn't protected. "

"Mars is abandoned, " replied General Logan seriously. "We haven't anytoo much to protect old Earth, and she must come first. Mars will, ofcourse, be protected as best the IP ships can. But--we're expectingdefeat. This isn't a case of glorious victory. It will be a case of hardwon survival. We don't know anything about the enemy--except that theyare capable of interstellar flights, and have atomic energy. They areevidently far ahead of us. Our battle is to survive till we learn how toconquer. For a time, at least, the Strangers will have possession ofmost of the planets of the system. We do not think they will be able toreach Earth, because Commander McLaurin here will withdraw his ships toEarth to protect the planet--and the great 'Lunar Bank' will display itstrue character. "

VII

Faragaut looked unsympathetically at Buck Kendall, as he stood glaringperplexedly at the apparatus he had been working on. 

"What's the matter, Buck, won't she perk?"

"No, damn it, and it should. "

"That, " pointed out Faragaut, "is just what you think. Nature thinksotherwise. We generally have to abide by her opinions. What is it--orwhat is it meant to be?"

"Perfect reflector. "

"Make a nice mirror. What else, and how come?"

"A mirror is just what I want. I want something that will reflect _all_the radiation that falls on it. No metal will, even in its range ofmaximum reflectivity. Aluminum goes pretty high, silver, on some ranges, a bit higher. But none of them reaches 99%. I want a perfect reflectorthat I can put behind a source of wild, radiant energy so I can focusit, and put it where it will do the most good. "

"Ninety-nine percent. Sounds pretty good. That's better efficiency thanmost anything else we have, isn't it?"

"No, it isn't. The accumulator is 100% efficient on the discharge, and agood transformer, even before that, ran as high as 99. 8 sometimes. Theyhad to. If you have a transformer handling 1, 000, 000 horsepower, andit's even 1% inefficient, you have a heat loss of nearly 10, 000horsepower to handle. I want to use this as a destructive weapon, and ifI hand the other fellow energy in distressing amounts, it's even worseat my end, because no matter how perfect a beam I work out, there willstill be some spread. I can make it mighty tight though, if I make mysurface a perfect parabola. But if I send a million horse, I have tohandle it, and a ship can't stand several hundred thousand horsepowerroaming around loose as heat, let alone the weapon itself. The thingwill be worse to me than to him. 

"I figured there was something worth investigating in those fields wedeveloped on our magnetic shield work. They had to do, you know, withlight, and radiant energy. There must be some reason why a metalreflects. Further, though we can't get down to the basic root of matter, the atom, yet, we can play around just about as we please with moleculesand molecular forces. But it is molecular force that determines whetherlight and radiant energy of that caliber shall be reflected ortransmitted. Take aluminum as an example. In the metallic moleculestate, the metal will reflect pretty well. But volatilize it, and itbecomes transparent. All gases are transparent, all metals reflective. Then the secret of perfect reflection lies at a molecular level in theorganization of matter, and is within our reach. Well--this thing wassupposed to make that piece of silver reflective. I missed it thattime. " He sighed. "I suppose I'll have to try again. "

"I should think you'd use tungsten for that. If you do have a slightleak, that would handle the heat. "

"No, it would hold it. Silver is a better conductor of heat. But thedarned thing won't work. "

"Your other scheme has. " Faragaut laughed. "I came out principally forsome signatures. IP wants one hundred thousand tons of mercury. I'vesold most of mine already in the open market. You want to sell?"

"Certainly. And I told you my price. "

"I know, " sighed Faragaut. "It seems a shame though. Those IP board menwould pay higher. And they're so damn tight it seems a crime not to make'em pay up when they have to. "

"The IP will need the money worse elsewhere. Where do I--oh, here?"

"Right. I'll be out again this evening. The regular group will be here?"

Kendall nodded as he signed in triplicate. 

 * * * * *

That evening, Buck had found the trouble in his apparatus, for as hewell knew, the theory was right, only the practical apparatus neededchanging. Before the group composed of Faragaut, McLaurin and themembers of Kendall's "bank, " he demonstrated it. 

It was merely a small, model apparatus, with a mirror of space-strainedsilver that was an absolutely perfect reflector. The mirror had beenground out of a block of silver one foot deep, by four inches square, carefully annealed, and the work had all been done in a cooling bath. The result was a mirror that was so nearly a perfect paraboloid that thebeam held sharp and absolutely tight for the half-mile range they testedit on. At the projector it was three and one-half inches in diameter. Atthe target, it was three and fifty-two one hundredths inches indiameter. 

"Well, you've got the mirror, what are you going to reflect with itnow?" asked McLaurin. "The greatest problem is getting a radiant source, isn't it? You can't get a temperature above about ten thousand degrees, and maintain it very long, can you?"

"Why not?" Kendall smiled. 

"It'll volatilize and leave the scene of action, won't it?"

"What if it's a gaseous source already?"

"What? Just a gas-flame? That won't give you the point source you need. You're using just a spotlight here, with a Moregan Point-light. Thatwon't give you energy, and if you use a gas-flame, the spread will be sogreat, that no matter how perfectly you figure your mirror, it won'tbeam. "

"The answer is easy. Not an ordinary gas-flame--a very extra-specialkind of gas-flame. Know anything about Renwright's ionization-work?"

"Renwright--he's an IP man isn't he?"

"Right. He's developed a system, which, thanks to the power we can getin that atostor, will sextuply ionize oxygen gas. Now: what does thatmean?"

"Spirits of space! Concentrated essence of energy!"

"Right. And in preparation, Cole here had one made up for me. That--andsomething else. We'll just hook it up--"

With Devin's aid, Kendall attached the second apparatus, a larger deviceinto which the silver block with its mirror surface fitted. With theuttermost care, the two physicists lined it up. Two projectors pointedtoward each other at an angle, the base angles of a triangle, whose apexwas the center of the mirror. On very low power, a soft, glowing violetlight filtered out through the opening of the one, and a slight greenlight came from the other. But where the two streams met, an intense, violet glare built up. The center of action was not at the focus, andslowly this was lined up, till a sharp, violet beam of light reached outacross the open yard to the target set up. 

Buck Kendall cut off the power, and slowly got into position. "Now. Keepout from in front of that thing. Put on these glasses--and watch out. "Heavy, thick-lensed orange-brown goggles were passed out, and Kendalltook his place. Before him, a thick window of the same glass had beenarranged, so that he might see uninterruptedly the controls at hand, andyet watch unblinded, the action of the beam. 

Dully the mirror-force relay clicked. A hazy glow ran over the silverblock, and died. Then--simultaneously the power was thrown from twosmall, compact atostors into the twin projectors. Instantly--a titaniceruption of light almost invisibly violet, spurted out in a solid, compact stream. With a roar and crash, it battered its way through thethick air, and crashed into the heavy target plate. A stream of flameand scintillating sparks erupted from the armor plate--and died asKendall cut the beam. A white-hot area a foot across leaked down theface of the metal. 

"That, " said Faragaut gently, removing his goggles. "That's not aspotlight, and it's not exactly a gas-flame. But I still don't know whatthat blue-hot needle of destruction is. Just what do you call that tamestellar furnace of yours?"

"Not so far off, Tom, " said Kendall happily, "except that even S Doradusis cold compared to that. That sends almost pure ultra-violetlight--which, by the way, it is almost impossible to reflectsuccessfully, and represents a temperature to be expressed not inthousands of degrees, nor yet in tens of thousands. I calculated thetemperature would be about 750, 000 degrees. What is happening is that astream of low-voltage electrons--cathode rays--in great quantity aremeeting great quantities of sextuply ionized oxygen. That means that anucleus used to having two electrons in the K-ring, and six in the next, has had that outer six knocked off, and then has been hurled violentlyinto free air. 

"All by themselves, those sextuply ionized oxygen atoms would have agood bit to say, but they don't really begin to talk till they startroaring for those electrons I'm feeding them. At the meeting point, theygrab up all they can get--probably about five--before the competitionand the fierce release of energy drives them out, part-satisfied. I losea little energy there, but not a real fraction. It's the howl they putup for the first four that counts. The electron-feed is necessary, because otherwise they'd smash on and ruin that mirror. They workpractically in a perfect vacuum. That beam smashes the air out of theway. Of course, in space it would work better. "

"How could it?" asked Faragaut, faintly. 

"Kendall, " asked McLaurin, "can we install that in the IP ships?"

"You can start. " Kendall shrugged. "There isn't a lot of apparatus. I'mgoing to install them in my ships, and in the--bank. I suspect--wehaven't a lot of time left. "

"How near ready are those ships?"

"About. That's all I can say. They've been torn up a bit forinstallation of the atostor apparatus. Now they'll have to be changedagain. "

"Anything more coming?"

Buck smiled slowly. He turned directly to McLaurin and replied:"Yes--the Strangers. As to developments--I can't tell, naturally. But ifthey do, it will be something entirely unexpected now. You see, givenone new discovery, a half-dozen will follow immediately from it. When weannounced that atostor, look what happened. Renwright must have thoughtit was God's gift to suffering physicists. He stuck some oxygen in thething, added some of his own stuff--and behold. The magnetic apparatusgave us directly the shield, and indirectly this mirror. Now, I seem tohave reached the end for the time. I'm still trying to get thatspace-release for high speed--speed greater than light, that is. Sofar, " he added bitterly, "all I've gotten as an answer is a singleexpression that simply means practical zero--Heisenberg's UncertaintyExpression. "

"I'm uncertain as to your meaning"--McLaurin smiled--"but I take itthat's nothing new. "

"No. Nearly four centuries old--twentieth century physics. I'll have totry some other line of attack, I guess, but that did seem so darnedright. It just sounded right. Something ought to happen--and it justkeeps saying 'nothing more except the natural uncertainty of nature. '"

"Try it out, your math might be wrong somewhere. "

Kendall laughed. "If it was--I'd hate to try it out. If it wasn't I'dhave no reason to. And there's plenty of other work to do. For onething, getting that apparatus in production. The IP board won't likeme. " Kendall smiled. 

"They don't, " replied McLaurin. "They're getting more and more and moreworried--but they've got to keep the IP fleet in such condition that itcan at least catch an up-to-date freighter. "

 * * * * *

Gresth Gkae looked back at Sthor rapidly dropping behind, and across ather sister world, Asthor, circling a bare 100, 000 miles away. Behind hisgreat interstellar cruiser came a long line of similar ships. Each wasloaded now not with instruments and pure scientists, but with weapons, fuel and warriors. Colonists too, came in the last ships. One hundredand fifty giant ships. All the wealth of Sthor and Asthor had beenconcentrated in producing those great machines. Every one representednearly the equivalent of thirty million Earth-dollars. Four and a halfbillions of dollars for mere materials. 

Gresth Gkae had the honor of lead position, for he had discovered theplanets and their stable, though tiny, sun. Still, Gresth Gkae knew hisown giant Mira was a super-giant sun--and a curse and a menace to anyrational society. Our yellow-white sun (to his eyes, an almost invisiblecolor, similar to our blue) was small, but stable, and warm enough. 

In half an hour, all the ships were in space, and at a given signal, atten-second intervals, they sprang into the superspeed, faster thanlight. For an instant, giant Mira ran and seemed distorted, as thoughseen through a porthole covered with running water, then steadied, curiously distorted. Faster than light they raced across the galaxy. 

Even in their super-fast ships, nearly three and a half weeks passedbefore the sun they sought, singled itself from the star-field as anextra bright point. Two days more, and the sun was within planetarydistance. They came at an angle to the plane of the ecliptic, but theyleveled down to it now, and slanted toward giant Jupiter and Jovianworlds. Ten worlds, in one sweep, it was--four habitable worlds. Thenine satellites would be converted into forts at once, ninespace-sweeping forts guarding the approaches to the planet. Gresth Gkaehad made a fairly good search of the worlds, and knew that Earth was themain home of civilization in this system. Mars was second, and Venusthird. But Jupiter offered the greatest possibilities for quicksettlement, a base from which they could more easily operate, a base forfuels, for the heavy elements they would need--

Fifteen million miles from Jupiter they slowed below the speed oflight--and the IP stations observed them. Instantly, according toinstructions issued by Commander McLaurin, a fleet of ten of thetiniest, fastest scouts darted out. As soon as possible, a group ofthree heavy cruisers, armed with all the inventions that had beendiscovered, the atostor power system, perfectly conducting power leads, the terrible UV ray, started out. 

The scouts got there first. Cameras were grinding steadily, with longrange telescopic lenses, delicate instruments probed and felt and caughttheir fingers in the fields of the giant fleet. 

At ten-second intervals, giant ships popped into being, and glidedsmoothly toward Jupiter. 

Then the cruisers arrived. They halted at a respectful distance, andwaited. The Miran ships plowed on undisturbed. Simultaneously, from thethree leaders, terrific neutron rays shot out. The paraffin block wallsstopped those--and the cruisers started to explain their feelings on thesubject. They were the IP-J-37, 39, and 42. The 37 turned up the fullpower of the UV ray. The terrific beam of ultra-violet energy struck thesecond Miran ship, and the spot it touched exploded into incandescence, burned white-hot--and puffed out abruptly as the air pressure withinblew the molten metal away. 

The Mirans were startled. This was not the type of thing Gresth Gkae hadwarned them of. Gresth Gkae himself frowned as the sudden roar of themachines of his ship rose in the metal walls. A stream of ten-inchatomic bombs shrieked out of their tubes, fully glowing green thingsfloated out more slowly, and immediately waxed brilliant. Gamma raybombs--but they could be guarded against--

The three Solarian cruisers were washed in such frightful flame as theyhad never imagined. Streams of atomic bombs were exploding soundlessly, ineffectively in space, not thirty feet from them as they felt thesudden resistance of the magnetic shields. Hopefully, the 39 probed withher neutron gun. Nothing happened save that several gamma ray bombs wentoff explosively, and all the atomic bombs in its path exploded at once. 

Gresth Gkae knew what that meant. Neutron beam guns. Then this race wasmore intelligent than he had believed. They had not had them before. Hadhe perhaps given them too much warning and information?

There was a sudden, deeper note in the thrumming roar of the greatship. Eagerly Gresth Gkae watched--and sighed in relief. The nearer ofthe three enemy ships was crumbling to dust. Now the other two werebeginning to become blurred of outline. They were fleeing--but oh, soslowly. Easily the greater ship chased them down, till only floatingdust, and a few small pieces of--

Gresth Gkae shrieked in pain, and horror. The destroyed ships had foughtin dying. All space seemed to blossom out with a terrible light, a lightthat wrapped around them, and burned into him, and through him. His eyeswere dark and burning lumps in his head, his flesh seemed crawling, stinging--he was being flayed alive--in shrieking agony he crumpled tothe floor. 

Hospital attachés came to him, and injected drugs. Slowly torturingconsciousness left him. The doctors began working over his horriblyburned body, shuddering inwardly as the protective, feather-likecovering of his skin loosened, and dropped from his body. Tenderly theylowered him into a bath of chemicals--

"The terrible light which caused so much damage to our men, " reported aphysicist, "was analyzed, and found to have some extraordinary lines. Itwas largely mercury-vapor spectrum, but the spectrum of mercury-atoms inan impossibly strained condition. I would suggest that great care beused hereafter, and all men be equipped with protective masks whenobservations are needed. This sun is very rich in the infra-X-rays andultra-visible light. The explosion of light, we witnessed, was dangerousin its consisting almost wholly of very short and hard infra-X-rays. "

The physicist had a special term for what we know as ultra-violet light. To him, blue was ultra-violet, and exceedingly dangerous tored-sensitive eyes. To him, our ultra-violet was a long X-ray, and wasdesignated by a special term. And to him--the explosion of the atostorreservoirs was a terrible and mystifying calamity. 

To the men in the five tiny scout-ships, it was also a surprise, and apainful one. Even space-hardened humans were burned by the terrificallyhard ultra-violet from the explosion. But they got some hint of what ithad meant to the Mirans from the confusion that resulted in the fleet. Several of the nearer ships spun, twisted, and went erratically offtheir courses. All seemed uncontrolled momentarily. 

The five scouts, following orders, darted instantly toward the LunarBank. Why, they did not know. But those were orders. They were to landthere. 

The reason was that, faster than any Solarian ship, radio signals hadreached McLaurin, and he, and most of the staff of the IP service hadbeen moved to the Lunar Bank. Buck Kendall had extended an invitation inthis "unexpected emergency. " It so happened that Buck Kendall'sinvitation got there before any description of the Strangers, or theiractions had arrived. The staff was somewhat puzzled as to how thishappened--

And now for the satellites of great Jupiter. 

One hundred and fifty giant interstellar cruisers advanced on Callisto. They didn't pause to investigate the mines and scattered farms of thesatellite, but ten great ships settled, and a horde of warriors beganpouring out. 

One hundred and forty ships reached Ganymede. One hundred and thirtysailed on. One hundred and thirty ships reached Europa--and they sailedon hurriedly, one hundred and twenty-nine of them. Gresth Gkae did notknow it then, but the fleet had lost its first ship. The IP station onEuropa had spoken back. 

They sailed in, a mighty armada, and the first dropped through Europa'sthin, frozen atmosphere. They spotted the dome of the station, and aneutron ray lashed out at it. On the other, undefended worlds, this hadbeen effective. Here--it was answered by ten five-foot UV rays. Further, these men had learned something from the destruction of the cruisers, and ten torpedoes had been unloaded, reloaded with atostor mercury, andsent out bravely. 

Easily the Mirans wiped out the first torpedo--

Shrieking, the Miran pilots clawed their way from the controls as thefearful flood of ultra-violet light struck their unaccustomed skins. Others too felt that burning flood. 

The second torpedo they caught and deflected on a beam ofalternating-current magnetism that repelled it. It did not come nearerthan half a mile to the ship. The third they turned their deflectingbeam on--and something went strangely wrong with the beam. It pulledthat torpedo toward the ship with a sickening acceleration--and thetorpedo exploded in that frightful violet flame. 

 * * * * *

Five-foot diameter UV beams are nothing to play with. The Mirans weredodging these now as they loosed atomic bombs, only to see them explodedharmlessly by neutron guns, or caught in the magnetic screen. Gamma raybombs were as useless. Again the beam of disintegrating force was turnedon--

The present opponent was not a ship. It was an IP defense station, equipped with everything Solarian science knew, and the dome was aneight-foot wall of tungsten-beryllium. The eight feet of solid, ultra-resistant alloy drank up that crumbling beam, and liked it. Thewall did not fail. The men inside the fort jerked and quivered as thestrange beam, a small, small fraction of it, penetrated the eight feetof outer wall, the six feet or so of intervening walls, and the mercuryatostor reserves. 

"Concentrate all those UV beams on one spot, and see if you can blast ahole in him before he shakes it loose, " ordered the ray technician. "He'll wiggle if you start off with the beam. Train your sights on thenose of that first ship--when you're ready, call out. "

"Ready--ready--" Ten men replied. "Fire!" roared the technician. Tentitanic swords of pure ultra-violet energy, energy that practically nounconditioned metal will reflect to more than fifty per cent, emerged. There was a single spot of intense incandescence for a single hundredthof a second--and then the energy was burning its way through the inner, thinner skins with such rapidity that they sputtered and flickered likea broken televisor. 

One hundred and twenty-nine ships retreated hastily for conference, leaving a gutted, wrecked hull, broken by its fall, on Europa. Triumphantly, the Europa IP station hurled out its radio message of thefirst encounter between a fort and the Miran forces. 

Most important of all, it sent a great deal of badly wanted informationregarding the Miran weapons. Particularly interesting was the fact thatit had withstood the impact of that disintegrating ray. 

VIII

Grimly Buck Kendall looked at the reports. McLaurin stood beside him, Devin sat across the table from him. "What do you make of it, Buck?"asked the Commander. 

"That we have just one island of resistance left on the Jovian worlds. And that will, I fear, vanish. They haven't finished with their arsenalby any means. "

"But what was it, man, what was it that ruined those ships?"

"Vibration. Somehow--Lord only knows how it's done--they can projectelectric fields. These projected fields are oscillated, and they aretuned in with some parts of the ship. I suspect they are crystals of themetals. If they can start a vibration in the crystals of themetal--that's fatigue, metal fatigue enormously speeded. You know how aquartz crystal oscillator in a radio-control apparatus will break, ifyou work it on a very heavy load at the peak? They simply smash thecrystals of metal in the same way. Only they project their field. "

"Then our toughest metals are useless? Can't something tough, ratherthan hard, like copper or even silver for instance, stand it?"

"Calcium metal's the toughest going--and even that would break under thebeating those ships give it. The only way to withstand it is to havesuch a mass of metal that the oscillations are damped out. But--"

The set tuned in on the IP station on Europa was speaking again. "Theships are returning. There are one hundred and twenty-nine by accuratecount. Jorgsen reports that telescopic observation of the dead on thefallen cruiser show them to be a _completely un-human race_! They areof mottled coloring, predominately grayish brown. The ships arereturning. They have divided into ten groups, nine groups of two each, and a main body of the rest of the fleet. The group of eighteen isdescending within range, and we are focusing our beams on them--"

Out by Europa, ten great UV beams were stabbing angrily toward ten greatinterstellar ships. The metal of the hulls glowed brilliant, anddistorted slowly as the thick walls softened under the heat, and the airbehind pressed against it. Grimly the ten ships came on. Torpedoes werebeing launched, and exploded, and now they had no effect, for the Miranswithin were protected. 

The eighteen grouped ships separated, and arranged themselves in acircle around the fort. Suddenly one staggered as a great puff of gasshot out through the thin atmosphere of Europa to flare brilliantly inthe lash of the stabbing UV beam. Instantly the ship righted itself, andlabored upward. Another dropped to take its place--

And the great walls of the IP fort suddenly groaned and started in theirwelded joints. The faint, whispering rustle of the crumbling beam wasmurmuring through the station. Engineers shouted suddenly as metersleapt the length of their scales, and the needles clicked softly on thestop pins. A thin rustle came from the atostors grouped in the greatpower room. "Spirits of Space--a revolving magnetic field!" roared theChief Technician. "They're making this whole blasted station a squirrelcage!"

The mighty walls of eight-foot metal shuddered and trembled. The UVbeams lashed out from the fort in quivering arcs now, they did not holdtheir aim steady, and the magnetic shield that protected them fromatomic bombs was working and straining wildly. Eighteen great shipsquivered and tugged outside there now, straining with all their power toremain in the same spot, as they passed on from one to another themagnetic impulses that were now creating a titanic magnetic vortex aboutthe fort. 

"The atostors will be exhausted in another fifteen minutes, " the ChiefTechnician roared into his transmitter. "Can the signals get throughthose fields, Commander?"

"No, Mac. They've been stopped, Sparks tells me. We're here--and let'shope we stay. What's happening?"

"They've got a revolving magnetic field out there that would spin aminor planet. The whole blasted fort is acting like the squirrel cage inan induction motor! They've made us the armature in a five hundredmillion horsepower electric motor. "

"They can't tear this place loose, can they?"

"I don't know--it was never--" The Chief stopped. Outside a terrificroar and crash had built up. White darts of flame leapt a thousand feetinto the air, hurling terrific masses of shattered rock and soil. 

"I was going to say, " the Chief went on, "this place wasn't designed forthat sort of a strain. Our own magnetic field is supporting us now, preventing their magnetic field from getting its teeth on metal. Whenthe strain comes--well, they're cutting loose our foundation with atomicbombs!"

Five UV beams were combined on one interstellar ship. Instantly thegreat machine retreated, and another dropped in to take its place whilethe magnetic field spun on, uninterruptedly. 

"Can they keep that up long?"

"God knows--but they have a hundred and more ships to send in when thepower of one gives out, remember. "

"What's our reserve now?"

The Chief paused a moment to look at the meters. "Half what it was tenminutes ago!"

Commander Wallace sent some other orders. Every torpedo tube of thestation suddenly belched forth deadly, fifteen-foot torpedoes, most ofthem mud-torpedoes, torpedoes loaded with high explosive in the nose, adelayed fuse, and a load of soft clinging mud in the rear. The mud wouldflow down over the nose and offer a resistance foot-hold for theexplosive which empty space would not. Four hundred and three torpedoes, equipped with anti-magnetic apparatus darted out. One hundred and fourpassed the struggling fields. One found lodgement on a Miran ship, andcrushed in a metal wall, to be stopped by a bulkhead. 

The Chief engineer watched his power declining. All ten UV beams wereunited in one now, driving a terrible sword of energy that made theattacked ship skip for safety instantly, yet the beams were all butuseless. For the Miran reserves filled the gap, and the magnetic tornadocontinued. 

For seventeen long minutes the station resisted the attack. Then thelast of the strained mercury flowed into the receivers, and the vastpower of the atostors was exhausted. Slowly the magnetic fieldsdeclined. The great walls of the station felt the clutching lines offorce--they began to heat and to strain. A low, harsh grinding becameaudible over the roar of the atomic bombs. The whole structure trembled, and jumped slightly. The roar of bombs ceased suddenly, as the stationjerked again, more violently. Then it turned a bit, rolled clumsily. Abruptly it began to spin violently, more and more rapidly. It startedrolling clumsily across the plateau--

A rain of atomic bombs struck the unprotected metal, and the eighthbreached the walls. The twentieth was the last. There was no longer anIP station on Europa. 

"The difference, " said Buck Kendall slowly, when the reports came infrom scout-ships in space that had witnessed the last struggle, "betweenan atomic generator and an atomic power-store, or accumulator, isclearly shown. We haven't an adequate _source_ of power. "

McLaurin sighed slowly, and rose to his feet. "What can we do?"

"Thank our lucky stars that Faragaut here, and I, bought up all themercury in the system, and had it brought to Earth. We at least have asupply of materials for the atostors. "

"They don't seem to do much good. "

"They're the best we've got. All the photocells on Earth and Venus andMercury are at present busy storing the sun's power in atostors. I havetwo thousand tons of charged mercury in our tanks here in the 'LunarBank. '"

"Much good that will do--they can just pull and pull and pull till it'sall gone. A starfish isn't strong, but he can open the strongest oysterjust because he can pull from now on. You may have a lot of power--but. "

"But--we also have those new fifteen-foot UV beams. And one fifteen-footUV beam is worth, theoretically, nine five-foot beams, and practically, a dozen. We have a dozen of them. Remember, this place was designed notonly to protect itself, but Earth, too. "

"They can still pull, can't they?"

"They'll stop pulling when they get their fingers burned. In themeantime, why not use some of those IP ships to bring in a few morecargoes of charged mercury?"

"They aren't good for much else, are they? I wonder if those fellowshave anything more we don't know?"

"Oh, probably. I'm going to work on that crumbler thing. That's thefirst consideration now. "

"Why?"

"So we can move a ship. As it is, even those two we built aren't anygood. "

"Would they be anyway?"

"Well--I think I might disturb those gentlemen slightly. Remember, theyeach have a nose-beam eighteen feet across. Exceedingly unpleasantcustomers. "

"Score: Strangers; magnetic field, atomic bombs, atomic power, crumblerray. Home team; UV beams. "

Kendall grinned. "I'd heard you were a pessimistic cuss when battlestarted--"

"Pessimistic, hell, I'm merely counting things up. "

"McClellan had all the odds on Lee back in the Civil War of theStates--but Lee sent him home faster than he came. "

"But Lee lost in the end. "

"Why bring that up? I've got work to do. " Still smiling, Kendall went tothe laboratory he had built up in the "Lunar Bank. " Devin was alreadythere, calculating. He looked unhappy. 

"We can't do anything, as far as I can see. They're using an electricfield all right, and projecting it. I can't see how we can do that. "

"Neither can I, " agreed Kendall, "so we can't use that weapon. I reallydidn't want to anyway. Like the neutron gun which I told CommanderMcLaurin would be useless as a weapon, they'd be prepared for it, youcan be sure. All I want to do is fight it, and make their projectionuseless. "

"Well, we have to know how they project it before we can break up theprojection, don't we?"

"Not at all. They're using an electric field of very high frequency, butvariable frequency. As far as I can see, all we need is a similarvariable electric field of a slightly different frequency to heterodynetheirs into something quite harmless. "

"Oh, " said Devin. "We could, couldn't we? But how are you going to dothat?"

"We'll have to learn, that's all. "

 * * * * *

Buck Kendall started trying to learn. In the meantime, the Mirans weretaking over Jupiter. There were three IP stations on the planet itself, but they were vastly hindered by the thick, almost ultra-violet-proofatmosphere of Jupiter. Their rays were weak. And the magnetic fields ofthe Mirans were unaffected. Only their atomic bombs were hindered by theheavier gravity that pulled the rocks back in place faster than thebombs could throw them out. Still--a few hours of work, and the IPstations on Jupiter had rolled wildly across the flat plains of theplanet like dented cans, to end in utter destruction. 

The Mirans had paid no attention to the fleeing passenger and freighterships that left the planet, loaded to the utmost with human cargo, andabsolutely no freight. The IP fleet had to go to their rescue withoxygen tanks to take care of the extra humans, but nearly three-quartersof the population of Jupiter, a newly established population, and hencea readily mobile one, was saved. The others, the Mirans did not botherwith particularly except when they happened to be near where the Miranswanted to work. Then they were instantly destroyed by atomic bombing, orgamma rays. 

The Mirans settled almost at once, and began their work of finding onJupiter the badly needed atomic fuels. Machines were set up, and workbegun, Mirans laboring under the gravity of the heavy planet. Then, fifty ships swam up again, reloaded with fuel, and with crews consistingsolely of uninjured warriors, and started for Mars. 

Mars was half way between her near conjunction and her maximumelongation with respect to Jupiter at that time. The Mirans knew theirbusiness though, for they started in on the IP station on Phobos. Theywere practiced by this time, and this IP station had only sevenfive-foot beams. In half an hour that station fell, and its sisterstation on Deimos followed. Three wounded ships returned to Jupiter, andten new ships came out. The attack on Mars itself was started. 

Mars was a different proposition. There were thirty-two IP stationshere, one of them nearly as powerful as the Lunar Bank station. It wasequipped with four of the huge fifteen-foot beams. And it had fifteentons of mercury, more than seven-eighths charged. The Mars CenterStation was located a short ten miles from the Mars Center City, andunder the immediate orders of the IP heads, Mars Center City had beenvacated. 

For two days the Mirans hung off Mars, solidifying their positions onPhobos and Deimos. Then, with sixty-two ships, they attacked. They hadmade some very astute observations, and they started on the smallerstations just beyond the range of the Mars Center Station. Naturally, near so powerful a center, these stations had never been strong. Theyfell rapidly. But they had been counted on by Mars Center as auxiliarysupports. McLaurin had sent very definite orders to Mars Centerforbidding any action on their part, save gathering of power-supplies. 

At last the direct attack on Mars Center was launched. For the firsttime, the Mirans saw one of the fifteen-foot beams. Mars' atmosphere isthin, and there is little ozone. The ultra-violet beams were nearly aseffective as in empty space. When the Mirans dropped their ships, a fullthirty of them, into the circle formation, Mars Center answered at once. All four beams started. 

Those fifteen-foot beams, connected directly to huge atostor releaseapparatus, delivered a maximum power of two and three-quarter billionhorsepower, each. The first Miran ship struck, sparkled magnificently, and a terrific cascade of white-hot metal rolled down from its nose. Thegreat ship nosed down and to the left abruptly, accelerated swiftly--andcrashed with tremendous energy on the plain outside of Mars Center City. White, unwavering flames licked up suddenly, and made a column fivehundred feet high against the dark sky. Then the wreck exploded with aviolence that left a crater half a mile across. 

Three other ships had been struck, and were rapidly retreating. Anothertry was made for the ring formation, and four more ships were wounded, and replaced. The ring did not retreat, but the great magnetic fieldstarted. Atomic and gamma ray bombs started now, flashing sometimesdangerously close to the station as its magnetic field battled therotating field of the ships. The four greater beams, and many smallerones were in swift and angry action. Not more than a ten-second exposurecould be endured by any one ship, before it must retreat. 

 * * * * *

For five minutes the Mirans hung doggedly at their task. Then, wisely, they retreated. Of the fleet, not more than seven ships remaineduntouched. Mars Center Station had held--at what cost only they knew. Five hundred tons of their mercury had been exhausted in that brief fiveminutes. One hundred tons a minute had flowed into and out of theatostor apparatus. Mars Center radioed for help, when the fleet lifted. 

There was one other station on Mars that stood a good chance ofsurvival, Deenmor Station, with three of the big beams installed, andapparatus for their fourth was in the station, and being rapidly workedover. McLaurin did a wise and courageous thing, at which every man onMars cursed. He ordered that all IP stations save these two be deserted, and all mercury fuel reserves be moved to Deenmor and Mars Center. 

The Mirans could not land on the North Western section of Mars, nor inthe South Central region. Therefore Mars was not exactly habitable toMiran ships, because the great beams had been so perfectly figured thatthey were effective at a range of nearly twelve hundred miles. 

Deenmor station was attacked--but it was a half-hearted attack, forMirans were becoming distinctly skittish about fifteen-foot UV beams. Two badly blistered ships--and the Mirans retreated to Jupiter. But Miraheld Phobos and Deimos. In two weeks, they had set up cannon there, andproved themselves accurate long-range gunners. Against the feebleattraction of Deimos, and with Mars' gravity to help them, they beganbombarding the two stations, and anything that attempted to approachthem, with gamma and atomic explosive bombs. Meanwhile they amusedthemselves occasionally by planting a gamma-ray bomb in each of Mars'major cities. They made Mars uninhabitable for Solarians as well as forMirans, at least until the deadly slow-action atomic explosives woreoff, or were removed. 

Then the Mirans, after a lapse of three weeks while they dug in theirtoes on Jupiter, prepared to leap. Earth was the next goal. Miranscout-ships had been sent out before this--and severely handled by theconcentrated fleets of the IP that hung grimly off Earth and Luna now. But the scouts had learned one thing. Mirans could never hope to attaina firm grasp on Earth while terribly armed Luna hung like a Sword ofDamocles over their heads. Further, attack on Earth directly would benext to impossible, for, thanks to Faragaut's Interplanetary Company, nearly all the mercury metal in the system was safely lodged on Earth, and saturated with power. Every major city had been equipped with greatUV apparatus. And neutron guns in plenty waited on small ships justoutside the atmosphere to explode harmlessly any atomic or gamma bombsMiran ships might attempt to deposit. 

An attack on Luna was the first step. But that terrible, gigantic forton Luna worried them. Yet while that fort existed, Earth ships were freeto come and go, for Mirans could not afford to stand near. At a distanceof twenty thousand miles, small Miran ships had felt the touch of thosegreat UV beams. 

Finally, a brief test-attack was made, with an entire fleet of onehundred ships. They drew almost into position, faster than light, fasterthan the signaling warnings could send their messages. In position, allthose great ships strained and heaved at the mighty magnetic vortex thattwisted at the field of the fort. Instantly, twelve of the fifteen-footUV beams replied. And--two great UV beams of a size the Mirans had neverseen before, beams from the two ships, "S Doradus" and "Cepheid. "

The test-attack dissolved as suddenly as it had come. The Miransreturned to Jupiter, and to the outer planets where they had furtherestablished themselves. Most of the Solar system was theirs. But theSolarians still held the choicest planets--and kept the Mirans fromusing the mild-temperatured Mars. 

IX

"They can't take this, at least, " sighed McLaurin as they retreated fromLuna. 

"I didn't think they could--right away. I'm wondering though if theyhaven't something we haven't seen yet. Besides which--give them time, give them time. "

"Well, give us time, too, " snapped McLaurin. "How are you coming?"

Buck smiled. "I'm sure I don't know. I have a machine but I haven't theslightest idea of whether or not it's any good. "

"Why not?"

"I can destroy--I hope--but I can't build up their ray. I can't test themachine because I haven't their ray to test it against. "

"What can we do to test it?"

"The only thing I can see is to call for volunteers--and send out asix-man cruiser. If the ship's too small, they may not destroy it withthe big crumbler rays. If it's too large--and the machine didn'twork--we'd lose too much. "

Twelve hours later, the IP men at the Lunar Bank fort were lined up. McLaurin stepped up on the platform, and addressed the men briefly, toldthem what was needed. Six volunteers were selected by a process ofelimination, those who were married, had dependents, officers, andothers were refused. Finally, six men of the IP were chosen, neitherrookies nor veterans, six average men. And one average six-man cruiser, one hundred and eleven feet long, twenty-two in diameter. It was theT-208, a sister ship of the T-247, the first ship to be destroyed. 

The T-208 started out from Luna, and with full acceleration, sped outtoward Phobos. Slowly she circled the satellite, while distant scoutskept her under view. Lazily, the Miran patrol on Phobos watched theT-208, indifferent to her. The T-208 dove suddenly, after five fruitlesscircles of the tiny world, and with her four-foot UV beam flaming, stabbed angrily at a flight of Miran scouts berthed in the very shadowof a great battle cruiser, one of the interstellar ships stationed hereon Phobos. 

Four of the little ships slumped in incandescence. Angrily the terrificsword of energy slashed at the frail little scouts. 

Angrily the Miran interstellar ship shot herself abruptly into actionagainst this insolent cruiser. The cruiser launched a flight of themercury-torpedoes. Flashing, burning, ultra-violet energy flooded thegreat ship, harmlessly, for the men were, as usual, protected. The Mirananswered with the neutron beam, atomic and gamma bombs--and the crumblerray. 

Gently, softly a halo of shimmering-violet luminescence built up aboutthe T-208. The UV beam continued to flare, wavering slightly in itsaim--then fell way off to one side. The T-208 staggered suddenly, wandered from her course--whole, but uncontrolled. For the men withinthe ship were dead. 

Majestically the Miran swung along beside the dead ship, a greatmagnetic tow-cable shot out toward it, to shy off at first, then slowlyto be adjusted, and take hold in the magnetic shield of the T-208. Thepilots of the watching scout-ships turned away. They knew what wouldhappen. 

It did. Five--ten--twenty seconds passed. Then the "dead-man" took overthe ship--and the stored power in the atostor tanks blasted in aterrible flame that shattered the metal hull to molecular fragments. Theinterstellar cruiser shuddered, and rolled half over at the blastingpressure. Leaking seams appeared in her plates. 

The scouts raced back to Luna as the Miran settled heavily, and a trifleclumsily to Phobos. Miran radio-beams were forcing their way out towardthe Miran station on Europa, to be relayed to the headquarters onJupiter, just as Solarian radio beams were thrusting through spacetoward Luna. Said the Miran messages: "Their ships no longer crumble. "Said the Solarian messages: "The ships no longer crumble--but the mendie. "

 * * * * *

His deep eyes burning tensely, Buck Kendall heard the messages comingin, and rose slowly from his seat to pace the floor. "I think I knowwhy, " he said at last. "I should have thought. For that too can beprevented. "

"Why--what in the name of the Planets?" asked McLaurin. "It didn't killthe men in the forts--why does it kill the men in the ships, when theships are protected?"

"The protection kills them. "

"But--but they had the protective oscillations on all the way out!"protested the Commander. 

"Think how it works though. Think, man. The enemy's field is anelectric-field oscillation. We combat it by setting up a similaroscillating field in the metal of the hull ourselves. Because the metalconducts the strains, they meet, and oppose. It is not a shield--ashield is impossible, as I have said, because of energy concentrationfactors. If their beam carried a hundred thousand horsepower in aten-foot square beam, in every ten square feet of our shield, we'd haveto have one hundred thousand horsepower. In other words, hundreds oftimes as much energy would be needed in the shield, as they used intheir beam. We can't afford that. We had to let the beams oppose ouroscillations in the metal, where, because the metal conducts, they meeton an equal basis. But--when two oscillations of slightly differentfrequency meet, what is the result?"

"In this case, a heterodyne frequency of a lower, and harmlessfrequency. "

"So I thought. I was partly right. It does _not_ harm the metal. But itkills the men. It is super-sonic. The terrible, shrill sounds destroythe cells of the men's bodies. Then, when their dead hands release thecontrols, the automatic switches blow up the ship. "

"God! We stop one menace--and it is like the Hydra. For every head welop off, two spring up. "

"Ah--but they are lesser heads. Look, what is the fundamental differencebetween sound and light?"

"One is a vibration of matter and the--ah--eliminate the materialcontact!"

"Exactly! All we need to do is to let the ships operate airless, the menin space suits. Then the air cannot carry the sounds to them. And byputting special damping materials in their suits, we can stop thevibrations that would reach them through their feet and hands. Anothersix-man ship must go out--but this ship will come back!"

And with the order for another experimental ship, went the orders forcommercial supplies of this new apparatus. Every IP ship must beequipped to resist it. 

Buck Kendall sailed on the six-man scout that went out this time. Againthey swooped once at Phobos, again Miran scout-ships crumbled under theattack of the vicious UV beams. The Mirans were not waitingcontemptuously this time. In an instant the great interstellar ship rosefrom its berth, its weapons working angrily. The crumbler ray snappedout at the T-253. 

Kendall stared into the periscope visor intently. Clumsily his paddedhands worked at the specially adapted controls. The soft hiss of theoxygen release into his suit disturbed him slightly. The radio-phones inhis helmet carried all the conversations in the ship to him with equalclarity. He watched as the great ship angled angrily up--

His vision was momentarily obscured by a violet glow that built up andreached out gently from every point of metal in the ship. The instantKendall saw that, the T-253 was fleeing under his hands. The test hadbeen made. Now all he desired was safety again. The ion-rockets flaredrecklessly as, crushed under an acceleration of four Earth-gravities, hesank heavily into his seat. Grimly the Miran ship was pursuing them, easily keeping up with the fleeing midget. The crumbler became moreintense, the violet glow more vivid. 

The UV beam was reaching out directly behind now. The--

With a cry of agony, Kendall ripped the radio-phone connection out ofhis suit. A soft hiss of leaking air warned him of too great violenceonly minutes later. For his ears had been deafened by the sudden shriekof a tremendous signal from outside!

Instantly Kendall knew what that meant. And he could not communicatewith his men! There was no metal in these special suits, even the oxygentanks were made of synthetic plastics of tremendous strength. No scrapof vibrating metal was permissible. The padded gloves and bootsprotected him--but there was a new and different type of crackle andhaze from the metal points now. It was almost invisible in thepractically airless ship, but Kendall saw it. 

Presently he felt it, as he desperately increased his acceleration. Slowcreeping heat was attacking him. The heat was increasing rapidly now. Desperately he was working at the crumbler-protection controls--butimmediately set them back as they were. He had to have the crumblerprotection as well--!

 * * * * *

Grimly the great Miran ship hung right beside them. Angrily the twofour-foot UV beams flashed back--seeking some weak spot. There werenone. At her absolute maximum of acceleration the little ship plungedon. Gamma and atomic bombs were washing her in flame. The heavy blocksof paraffin between her walls were long since melted, retained only bythe presence of the metal walls. Smoke was beginning to filter out now, and Kendall recognized a new, and deadlier menace! Heat--quantities ofheat were being poured into the little ship, and the neutron guns weredoing their best to add to it. The paraffin was confined in there--andlike any substance, it could be volatilized, and as a vapor, developpressure--explosive pressure!

The Miran seemed satisfied in his tactics so far--and changed them. Forty-seven million miles from Earth, the Miran simply accelerated a bitmore, and crowded the Solarian ship a bit. White-faced, Buck Kendall wasforced to turn a bit aside. The Miran turned also. Kendall turned a bitmore--

Flashing across his range of vision at an incredible speed, a tinything, no more than twenty feet long and five in diameter, a scout-shipappeared. Its tiny nose ultra-violet beam was blasting a solid cylinderof violet incandescence a foot across in the hull of the Miran--and, tothe Miran, angling swiftly across his range of vision. Its magneticfield clashed for a thousandth of a second with the T-253, instantlymeeting, and absorbing the fringing edges. Then--it swept through theMiran's magnetic shield as easily. The delicate instruments of the scoutinstantaneously adjusted its own magnetic field as much as possible. There was resistance, enormous resistance--the ship crumpled in onitself, the tail vanished in dust as a sweeping crumbler beam caught itat last--and the remaining portion of the ship plowed into the nose ofthe Miran. 

The Miran's force-control-room was wrecked. For perhaps a minute and ahalf, the ship was without control, then the control wasre-established--and in vain the telescopes and instruments searched forthe T-253. Lightless, her rockets out now, her fields damped down toextinction, the T-253 was lost in the pulsing, gyrating fields of half adozen scout-ships. 

Kendall looked grimly at the crushed spot on the nose of the Miran. Hisship was drifting slowly away from the greater ship. Presently, however, the Miran put on speed in the direction of Earth, and the T-253 fell farbehind. The Miran was not seriously injured. But that scout pilot, insacrificing life, had thrown dust in their eyes for just those fewmoments Kendall had needed to lose a lightless ship in lightlessspace--lightless--for the Mirans at any rate. The IP ships had beencovered with a black paint, and in no time at all, Kendall had gottenhis ship into a position where the energy radiations of the sun made himundetectable from the Miran's position, since the radiation of his ownship, even in the heat range, was mingled with the direct radiation ofthe sun. The sun was in the Miran's "eyes, " both actual andinstrumental. 

An hour later the Miran returned, passed the still-lightless ship at adistance of five million miles, and settled to Phobos for the slightrepairs needed. 

Twelve hours later, the T-253 settled to Luna, for the manyrearrangements she would need. 

"I rather knew it was coming, " Kendall admitted sadly, "but danged if Ididn't forget all about it. And--cost the life of one of the finest menin the system. Jehnson's family get a permanent pension just twice hissalary, McLaurin. In the meantime--"

"What was it? Pure heat, but how?"

"Pure radio. Nothing but short-wave radio directed at us. They probablyhad the apparatus, knew how to make it, but that's not a good type ofheat ray, because a radio tube is generally less than eighty percentefficient, which is a whale of a loss when you're working in a battle, and a whale of an inconvenience. We were heated only four times as muchas the Miran. He had to pump that heat into a heat-reservoir--a watertank probably--to protect himself. Highly inefficient and ineffectiveagainst a large ship. Also, he had to hold his beam on us nearly tenminutes before it would have become unbearable. He was again, trying tokill the men, and not the ship. The men are the weakest point, obviously. "

"Can you overcome that?"

"Obviously, no. The thing works on pure energy. I'd have to match hisenergy to neutralize it. You knew it's an old proposition, that if youcould take a beam of pure, monochromatic light and divide it exactly inhalf, and then recombine it in perfect interference, you'd haveannihilation of energy. Cancellation to extinction. The trouble is, younever do get that. You can't get monochromatic light, because lightcan't be monochromatic. That's due to the Heisenberg Uncertainty--my petbug-bear. The atom that radiates the light, must be moving. If it isn't, the emission of the light itself gives it a kick that moves it. Now, nomatter what the quantum _might_ have been, it loses energy in kickingthe atom. That changes the situation instantly, and incidentally the'color' of the light. Then, since all the radiating atoms won't bemoving alike, etc. , the mass of light can't be monochromatic. Thereforeperfect interference is impossible. 

"The way that relates to the problem in hand, is that we can't possiblydestroy his energy. We can, as we do in the crumbler stunt, change it. He can't, I suspect, put too much power behind his crumbler, or he'dhave crumbling going on at home. We get a slight heating from it, anyway. Into the bargain, his radio was after us, and his neutronsnaturally carried energy. Now, no matter what we do, we've got that tohandle. When we fight his crumbler, we actually add heat-energy to it, ourselves, and make the heating effect just twice as bad. If we try toheterodyne his radio--presto--it has twice the heat energy anyway, though we might reduce it to a frequency that penetrated the shipinstead of all staying in it. But by the proposition, we have to use asmuch energy, and in fact, remember the 80% rule. We've got to take itand like it. "

"But, " objected McLaurin, "we _don't_ like it. "

"Then build ships as big as his, and he'll quit trying to roast you. Particularly if the inner walls are synthetic plastics. Did you know Iused them in the 'S Doradus' and 'Cepheid'?"

"Yes. Were you thinking of that?"

"No--just luck--and the fact that they're light, strong as steel almost, and can be manufactured in forms much more quickly. Only the outer hullis tungsten-beryllium. The advantage in this will be that nearly all theenergy will be absorbed outside, and we'll radiate pretty fast, particularly as that tungsten-beryllium has a high radiation-factor inthe long heat range. "

"What does that mean?"

"Well, ordinary polished silver is a mighty poor radiator. Homelyexample: Try waiting for your coffee to cool if it's in a polishedsilver pot. Then try it in a tungsten-beryllium pot. No matter how youpolish that tungsten-beryllium, the stuff WILL radiate heat. That's whyan IP ship is always so blamed cold. You know the passenger ships usepolished aluminum outer walls. The big help is, that thetungsten-beryllium will throw off the energy pretty fast, and in a bigship, with a whale of a lot of matter to heat, the Strangers will simplygive up the idea. "

"Yes, but only two ships in the system compare with them in size. "

"Sorry--but I didn't build the IP fleet, and there are lots of tungstenand beryllium on Earth. Enough anyway. "

"Will they use that beam on the fort? And can't we use the thing onthem?"

"They won't and we won't--though we could. A bank of those new millionwatt tubes--perhaps a hundred of them--and we'd have a pretty effectiveheater--but an awful waste of power. I've got something better. "

"New?"

"Somewhat. I've found out how to make the mirror field in a plate ofmetal, instead of a block. Come on to the lab, and I'll show you. "

"What's the advantage? Oh--weight saved, and silver metal saved. "

"A lot more than that, Mac. Watch. "

 * * * * *

At the laboratory, the new apparatus looked immensely lighter andsimpler than the old. The atostor, the ionizer, and the twinion-projectors were as before, great, rigid, metal structures that wouldmaintain the meeting point of the ions with inflexible exactitude underany acceleration strains. But now, instead of the heavy silver block inwhich a mirror was figured, the mirror consisted of a polished silverplate, parabolic to be sure, but little more than a half-inch inthickness. It was mounted in a framework of complex, stout metal braces. 

Kendall started the ion-flame at low intensity, so the UV beam waslittle more than a spotlight. 

"You missed the point, Mac. Now--watch that tungsten-beryllium plate. I'll hold the power steady. It's an eighteen-inch beam--and now theenergy is just sufficient to heat that tungsten plate to bright red. But--"

Kendall turned over a small rheostat control--and abruptly theeighteen-inch diameter spot on the tungsten-beryllium plate begancontracting; it contracted till it was a blazing, sparkling spot ofmolten incandescence less than an inch across!

"That's the advantage of focus. At this distance of a few hundred feetwith a small beam I can do that. With a twenty-foot beam, I can get atwo-foot spot at a distance of nearly ten miles! That means that thereceiving end will have the pleasure of handling _one hundred times theenergy concentration_. That would punch a hole through most anything. All you have to do is focus it. The trouble being, if it's out of focusthe advantage is more than lost. So if there's any question aboutgetting the focus, we'll get along without it. "

"A real help, if you do. That would punch a hole before the Strangership could turn away as they do now. "

Kendall nodded. "That's what I was after. It is mainly for the forts, though. We'll have to signal the dope to the Mars Center and Deenmorstations. They can fix it up, themselves. In the meantime--all we can dois hold on and hunt, and let's hope better than the Strangers do. "

X

Sadly the convalescent Gresth Gkae listened to the reports of hislieutenants. More and more disgraced he felt as he realized how badly hehad blundered in reporting the people of this system unable to cope withthe attackers' weapons. Gresth Gkae looked up at his old friend andphysician, Merth Skahl. He shook his head slowly. "I'm afraid, MerthSkahl. I am afraid. We have, perhaps, made a mistake. The better and thestronger alone should rule. Aye, but is the _stronger_ always the_better_? I am afraid we have mistaken the Truth in assuming this. If wehave--then may Jarth, Lord of Truth and Wisdom punish us. Mighty Jarth, if I have mistaken in following my judgments, it is not fromdisobedience, it is lack of Thy knowledge. The strongest--they are notalways the better, are they?"

Merth Skahl bent sharply over his friend. "Quiet thyself, Gresth Gkae. You know, and I know, you have done only your best, and surely Jarthhimself can ask no better of any one. You must rest, for only by restcan those terrible burns be healed. All your _stheen_ over half thebody-area was burned off. You have been delirious for many days. "

"But Merth Skahl, think--have we disobeyed Jarth's will? It is, we know, his will that only the best and the strongest shall rule--but are thebest always the strongest? An imbecile adult could destroy the life of agenius-grade child. The strongest wins, but not the best. Such would notbe the will of Jarth. If we be the stronger, _and_ the best, then it isright and just that these strange creatures should be destroyed that wemay have a stable world of stable light and heat. But look and see, withwhat terrible swiftness these strange creatures have learned! May it notbe they are the better race--that it is _we_ who are the weaker and thepoorer? Can it be that Jarth has brought us together that these peoplemight learn--and destroy us? If they be the stronger, and thebetter--then may Jarth's will be done. But we must test our strength tothe utmost. I must rise, and go to my laboratory soon. They have set itup?"

"Aye, they have, Gresth Gkae. But remember, the weak and the sick makefaults the strong and the well do not. Better that you rest yourself. There is little you can do while your body seeks to recover from theseterrible burns. "

"You are wrong, my friend, wrong. Don't you see that my mind isclear--that it is the mind which must fight in these battles, for surelythe man is weak against such things as this infra-X-radiation? Why, I ambetter able to fight now than are you, for I am a trained fighter of themind, while you are a trained healer of the body. These strange beingswith their stiff arms and legs, their tender skins, and--and their swiftminds have fought us all too well. If we must test, let it be a test. Ihave heard how they so quickly solved the riddle of the crumbling field. That took us longer, and we designed it. The Counsel of Worlds put me incommand, let me up, Skahl, I must work. "

Concerned, the physician looked down at him. Finally he spoke again. "No, I will not permit you to leave the hospital-ship. You must stayhere, but if, as you have said, the mind is what must fight, then surelyyou can fight well from here, for your mind is here. "

"No, I cannot, and you well know it. I may shorten my life, but whatmatter. 'Death is the end toward which the chemical reaction, Life, tends, '" quoted the scientist. "You know I have left my children--myimmortality is assured through them. I can afford to die in peace, if itassures their welfare. Time is precious, and while my mind might workfrom here, it must have data on which to work. For that, I must go tothe laboratories. Help me, Merth Skahl. "

Reluctantly the physician granted the request, but begged of Gresth Gkaea promise of at least six hours rest in every fifteen, and a good sleepof at least twenty-seven hours every "night. " Gresth Gkae agreed, andfrom a wheelchair, conducted his work, began a new line ofexperimentation he hoped would yield them the weapon they needed. Underhim, the staff of scientists worked, aiding and advising and suggesting. The apparatus was built, tested, and found wanting. Time and again asthe days passed, they watched Gresth Gkae, gaining strength very, veryslowly, taken away despondent at the end of his forty hours of work. 

A dozen expeditions were sent to Jupiter's poles to watch and measureand study the tremendous auroral displays there, where Jupiter's vastmagnetic field sucked in countless quintillions of the flying electronsfrom the sun, and brought them circling in, in a vast, magnificentdisplay of auroral ionization. 

 * * * * *

Expeditions went to the great Southern Plateau, the Plateau of Storms, where the titanic air currents resulted in an everlasting display ofterrific lightnings, great burning balls of electric force floatingdangerous and deadly across the frozen, ultra-cold plain. 

And the expeditions brought back data. Yet still Gresth Gkae could notsleep, his thoughts intruding constantly. Hours Merth Skahl spent withhim, calming him to sleep. 

"But what is this constant search? It is little enough I know ofscience, but why do you send our men to these spots of wonderfullybeautiful, but useless natural forces. Can we somehow, do you think, turn them against the people of these worlds?"

Softly the old Miran smiled. "Yes, you might say so. For look, it is thestrange balls of electric force I want to know about. Sthor had few, butoccasionally we saw them. Never were they properly investigated. I wantto know their secret, for I am sure they are balls of electric forcesnot vastly dissimilar from the nucleus of the atom. Always we have knownthat no system of purely electrical forces could remain stable. Yetthese strange balls of energy do. How is it? I am sure it will be ofvast importance. But the direct secret I hope to learn is in this: Whatcan be done with electric fields can nearly always be duplicated, orparalleled in magnetic fields. If I can learn how to make theseelectric balls of energy, can I not hope to make similar magnetic ballsof energy?"

"Yes, I see--that would seem true. But what benefit would you derivefrom that? You have magnetic beams now, and yet they are useless becauseyou can get nowhere near the forts. How then would these benefit you?"

"We can do nothing to those forts, because of that magnetic shield. Could we once break it down, then the fort is helpless, and one or twosmall atomic bombs destroy it. But--we cannot stay near, for theterrible infra-X-rays of theirs burn holes in our ships, and--in ourmen. 

"But look you, I can drop many atomic bombs from a distance where theirbeams are ineffective. Suppose I _do_ make a magnetic ball of energy, amagnetic bomb. Then--I can drop it from a distance! We have learned thatthe power supply of these forts is very great--but not endless, as isours now, thanks to the vast supplies of power metal on this heavyplanet. Then all we need do is stay at a distance where they cannotreach us--and drop magnetic bombs. Ah, they will be stopped, and theirenergy absorbed. But we can keep it up, day after day, and slowly drainout their power. Then--then our atomic bombs can destroy those forts, and we can move on!" But suddenly the animation and strength left hisvoice. He turned a sad, downcast face to his friend. "But Merth Skahl, we can't do it, " he complained. 

"Ah--now I can see why you so want to continue this wearing and worryingwork. You need time, Gresth Gkae, only time for success. Tomorrow it maybe that you will see the first hint that will lead you to success. "

"Ah--I only hope it, Merth Skahl, I only hope it. "

But it was the next day that they saw the first glimpse of the secret, and saw the path that might lead to hope and success. In a week theywere sending electric bombs across the laboratory. And in three daysmore, a magnetic bomb streaked dully across the laboratory to a magneticshield they had set up, and buried itself in it, to explode in brilliantlight and heat. 

From that day Gresth Gkae began to mend. In the three weeks that wereneeded to build the apparatus into ships, he regained strength so thatwhen the first flight of five interstellar ships rose from Jupiter, hewas on the flagship. 

To Phobos they went first, to the little inner satellite of Mars, scarcely eight miles in diameter, a tiny bit of broken metal and rock, utterly airless, but scarcely more than 3700 miles from the surface ofMars below. The Mars Center and Deenmor forts were wasting no powerraying a ship at that distance. They could, of course, have damaged it, but not severely enough to make up for the loss of their strictlylimited power. The photocells had been working overtime, every minute ofavailable light had been used, and still scarcely 2100 tons of chargedmercury remained in the tanks of Mars Center and 1950 in the tanks atDeenmor. 

The flight of five ships settled comfortably upon Phobos, while thethree relieved of duty started back to Jupiter. Immediately work wasbegun on the attack. The ships were first landed on the near side, whilethe apparatus of the projectors was unloaded, then the great ships movedaround to the far side. Phobos of course rotated with one face fixedirrevocably toward Mars itself, the other always to the cold of space. Great power leads trailed beneath the ships, and to the dark side. Thenthere were huge water lines for cooling. On this almost weightlessworld, where the great ships weighing hundreds of thousands of tons on aplanet, weighed so little they were frequently moved about by a singleman, the laying of five miles of water conduit was no impossibility. 

Then they were ready. Mars Center came first. Automatic devices kept theaim exact, as the first of the magnetic bombs started down. Atfive-second intervals they were projected outward, invisible globes ofconcentrated magnetic energy, undetectable in space. Seven secondspassed before the first became dimly visible in the thin air of Mars. Itfloated down, it would miss the fort it seemed--so far to one side--Abruptly it turned, and darted with tremendously accelerating speed forthe great magnetic field of the fort. With a vast blast of light, itexploded. Five seconds later a second exploded. And a third. 

Mars Center signaled scoffingly that the bombs were all being stoppeddead in the magnetic atmosphere, after the bombardment had beenwitnessed from Earth and Luna. An hour later they gave a report thatthey were concentrated magnetic fields of energy that would be ratherdangerous--if it weren't that they couldn't even stand into the magneticatmosphere. Three hours later Mars Center reported that they containedconsiderably more energy than had at first been thought. Further, whichthey had not carefully considered at first, they were taking energy withthem! They were taking away about an equal amount of energy as each blewup. 

It was only a half-hour after that that the men at Mars Center realizedperfectly what it meant. Their power was being drained just a little bitbetter than twice as fast as they generated during the day--and sincePhobos spun so swiftly across the sky. 

Deenmor got the attack just about the time Mars Center was released. Deenmor immediately began seeking for the source of it. Somewhere onPhobos--but where?

The Mirans were experts at camouflage. Deenmor Station, realizing themenace, immediately rayed the "projector. " They tore up a great deal ofharmless rock with their huge UV rays. But the bomb device continued tothrow one bomb each five seconds. 

When Deenmor operated from Phobos' position, Mars Center was exposed tothe deadly, constant drain. A day or two later, the bombs were comingone each second and a half, for more ships had joined in the work onPhobos. 

Gresth Gkae saw the work was going nicely. He knew that now it was onlya question of time before those magnetic shields would fail--and thenthe whole fort would be powerless. Maybe--it might be a good idea, whenthe forts were powerless to investigate instead of blowing them up. There might be many interesting and worthwhile pieces ofapparatus--particularly the UV beam's apparatus. 

XI

Buck Kendall entered the Communications room rather furtively. He hatedthe place. Cole was there, and McLaurin. Mac was looking tired anddrawn, Cole not so tired, but equally drawn. The signals were comingthrough fairly well, because most of the disturbance was rising wherethe signals rose, and all the disturbance, practically, was magneticrather than electric. 

"Deenmor is sending, Buck, " McLaurin said as he entered. "They're downto the last fifty-five tons. They'll have more time now--a rest whilePhobos sinks. Mars Center has another 250 tons, but--it's just aquestion of time. Have you any hope to offer?"

"No, " said Kendall in a strained voice. "But, Mac, I don't think menlike those are afraid to die. It's dying uselessly they fear. Tell'em--tell 'em they've defended not alone Mars, but all the system, inholding up the Strangers on Mars. We here on Luna have been saferbecause of them. And tell--Mac, tell them that in the meantime, whilethey defended us, and gave us time to work, we have begun to see thetrail that will lead to victory. "

"_You have!_" gasped McLaurin. 

"No--but they will never know!" Kendall left hastily. He went and stoodmoodily looking at the calculator machines--the calculator machines thatrefused to give the answers he sought. No matter how he might modifythat original idea of his, no matter what different line of attack hemight try in solving the problems of Space and Matter, while he used thesystem he _knew_ was right--the answer came down to that deadly, hope-blasting expression that meant only "uncertain. "

Even Buck was beginning to feel uncertain under that constant crushingof hope. Uncertainty--uncertainty was eating into him, and destroying--

From the Communications room came the hum and drive of the great senderflashing its message across seventy-two millions of miles of nothing. "B-u-c-k K-e-n-d-a-l-l s-a-y-s h-e h-a-s l-e-a-r-n-e-d s-o-m-e-t-h-i-n-gt-h-a-t w-i-l-l l-e-a-d t-o v-i-c-t-o-r-y w-h-i-l-e y-o-u h-e-l-db-a-c-k t-h-e--"

Kendall switched on a noisy, humming fan viciously. The too-intelligiblesignals were drowned in its sound. 

"And--tell them to--destroy the apparatus before the last of the poweris gone, " McLaurin ordered softly. 

The men in Deenmor station did slightly better than that. Gradually theycut down their magnetic shield, and some of the magnetic bombs tore andtwisted viciously at the heavy metal walls. The thin atmosphere of Marsleaked in. Grimly the men waited. Atomic bombs--or ships to investigate?It did not matter much to them personally--

Gresth Gkae smiled with his old vigor as he ordered one of the greatinterstellar ships to land beside the powerless station, approachingfrom such an angle that the still-active Mars Center station could notattack. One of the fleet of Phobos rose, and circled about the planet, and settled gracefully beside the station. For half an hour it lay therequietly, waiting and watching. Then a crew of two dozen Mirans startedacross the dry, crumbly powder of Mars' sands, toward the fort. Simultaneously almost, three things happened. A three-foot UV beam wipedout the advancing party. A pair of fifteen-foot beams cut a great gapinghole in the wall of the interstellar ship, as it darted up, like astartled quail, its weapons roaring defiance, only to fall back, severely wounded. 

And the radio messages pounded out to Earth the first description of theMiran people. Methodically the men in Deenmor station used all but oneton of their power to completely and forever wreck and destroy theinterstellar cripple that floundered for a few moments on the sands abare mile away. Presently, before Deenmor was through with it, theatomic bombs stopped coming, and the atomic shells. The magnetic shieldthat had been re-established for the few minutes of this last, dyingsting, fell. 

Deenmor station vanished in a sudden, colossal tongue of blue-greenlight as the ton of atomically distorted mercury was exploded by aprojector beam turned on the tank. 

 * * * * *

It was long gone, when the first atomic bombs and magnetic bombs droppedfrom Phobos reached the spot, and only hot rock and broken metalremained. 

Mars Center failed in fact the next time Phobos rode high over it. Theapparatus here had been carefully destroyed by technicians with a viewof making it indecipherable, but the Mirans made it even more certain, for no ship settled here to investigate, but a stream of atomic bombsthat lasted for over an hour, and churned the rock to dust, and the dustto molten lava, in which pools of fused tungsten-beryllium alloy bubbledslowly and sank. 

"Ah, Jarth--they are a brave race, whatever we may say of their queershape, " sighed Gresth Gkae as the last of Mars Center sank in bubblinglava. "They stung as they died. " For some minutes he was silent. 

"We must move on, " he said at length. "I have been thinking, and itseems best that a few ships land here, and establish a fort, while sometwenty move on to the satellite of the third planet and destroy the fortthere. We cannot operate against the planet while that hangs above us. "

Seven ships settled to Mars, while the fleet came up from Jupiter tojoin with Gresth Gkae's flight of ships on its way to Luna. 

An automatically controlled ship was sent ahead, and began thebombardment. It approached slowly, and was not destroyed by the UV beamstill it had come to within 40, 000 miles of the fort. At 60, 000 GresthGkae stationed his fleet--and returned to 150, 000 immediately as thetitanic UV beams of the Lunar Fort stretched out to their maximum range. The focus made a difference. One ship started limping back to Jupiter, in tow of a second, while the rest began the slow, methodical work ofwearing down the defenses of the Lunar Fort. 

Kendall looked out at the magnificent display of clashing, warringenergies, the great, whirling spheres and discs of opalescent flame, andturned away sadly. "The men at Deenmor must have watched that for days. And at Mars Center. "

"How long can we hold out?" asked McLaurin. 

"Three weeks or so, at the present rate. That's a long time, really. Andwe can escape if we want to. The UV beams here have a greater range thanany weapon the Strangers have, and with Earth so near--oh, we couldescape. Little good. "

"What are you going to do?"

"I, " said Buck Kendall, suddenly savage, "am going to consign all themath machines in the universe to eternal damnation--and go ahead andbuild a machine anyway. I _know_ that thing ought to be right. Themath's wrong. "

"There is no other thing to try?"

"A billion others. I don't know how many others. We ought to get atomicenergy somehow. But that thing infuriates me. A hundred things that mathhas predicted, that I have checked by experiment, simple little things. But--when I carry it through to the point where I can get somethinguseful--it wriggles off into--uncertainty. "

Kendall stalked off to the laboratory. Devin was there working over thecalculus machines, and Kendall called him angrily. Then more apologetic, he explained it was anger at himself. "Devin, I'm going to make thatthing, if it blows up and kills me. I'm going to make that thing if thiswhole fort blows up and kills me. That math has blown up in my face forfour solid months, and half killed me, so I'm going to kill it. Come on, we'll make that damned junk. "

Angrily, furiously, Kendall drove his helpers to the task. He had workedout the apparatus in plan a dozen times, and now he had the plans turnedinto patterns, the patterns into metal. 

Saucily, the "S Doradus" made the trip to and from Earth with patterns, and with metal, with supplies and with apparatus. But she had to dodgeand fight every inch of the way as the Miran ships swooped down angrilyat her. A fighting craft could get through when the Miran fleet waswithdrawn to some distance, but the Mirans were careful that noheavy-loaded freighter bearing power supply should get through. 

And Gresth Gkae waited off Luna in his great ship, and watched thesteady streams of magnetic bombs exploding on the magnetic shield of theLunar Fort. Presently more ships came up, and added their power to theattack, for here, the photo-cell banks could gather tremendous energy, and Gresth Gkae knew he would need to overcome this, and drain theaccumulated power. 

Gresth Gkae felt certain if he could once crack this nut, break downEarth, he would have the system. This was the home planet. If this fell, then the two others would follow easily, despite the fact that the fewforts on the innermost planet, Mercury, could gather energy from the sunat a rate greater than their ships could generate. 

It took Kendall two weeks and three days to set up his preliminaryapparatus. They had power for perhaps four days more, thanks to the factthat the long Lunar day had begun shortly after Gresth Gkae's impatientattack had started. Also, the "S Doradus" had brought in several hundredtons of charged mercury on each trip, though this was no great quantityindividually, it had mounted up in the ten trips she had made. The"Cepheid, " her sister ship, had gone along on seven of the trips, andadded to the total. 

But at length the apparatus was set up. It was peculiar looking, and itemployed a great deal of power, nearly as much as a UV beam in fact. McLaurin looked at it sceptically toward the last, and asked Buck: "Whatdo you expect it to do?"

"I am, " said Kendall sourly, "uncertain. The result will be uncertaintyitself. "

Which, considering things, was a surprisingly accurate statement. Kendall gave the exact answer. He meant to give an ironic comment. Forthe mathematics had been perfectly correct, only Buck Kendallmisinterpreted the answer. 

"I've followed the math with mechanism all the way through, " heexplained, "and I'm putting power into it. That's all I know. Somewhere, by the laws of cause and effect, this power _must_ show itselfagain--despite what the damn math says. "

And in that, of course, Kendall was wrong. Because the laws of cause andeffect didn't hold in what he was doing now. 

"Do you want to watch?" he asked at length. "I'm all set to try it. "

"I suppose I may as well. " McLaurin smiled. "In our close-knit littlecommunity the fate of one is of interest to all. If it's going to blowup, I might as well be here, and if it isn't, I want to be. "

Kendall smiled appreciatively and replied: "Let it be on thy own head. Here she goes. "

He walked over to the power board, and took command. Devin, and a squadof other scientists were seated about the room with every conceivabletype and combination of apparatus. Kendall wanted to see what this wasdoing. "Tubes, " he called. "Circuits A and D. Tie-ins. " He stopped, thepreliminary switches in. "Main circuit coming. " With a jerk he threwover the last contact. A heavy relay thudded solidly. The hum of astraining atostor. Then--

An electric motor, humming smoothly stopped with a jerk. "This, " itremarked in a deep throaty voice, "is probably the last stand ofhumanity. "

The galvanometer before which Devin was seated apparently agreed. In arather high pitched voice it pointed out that: "If the Lunar Fort falls, the Earth--" It stopped abruptly, and an electroscope beside Douglasstook up the thread in a high, shrill voice, rather slurred, "--will bedirectly attacked. "

"This, " resumed the motor in a hoarse voice, "will certainly mean theend of humanity. " The motor gave up the discourse and hummed violentlyinto action--in reverse!

"My God!" Kendall pulled the switch open with a sagging jaw and staringeyes. 

The men in the room burst into sudden startled exclamations. 

Kendall didn't give them time. His jaw snapped shut, and a blazing lightof wondrous joy shone in his eyes. He instantly threw the switch inagain. Again the humming atostor, the strain--

Slowly Devin lifted from his seat. With thrashing arms and startled, staring eyes, he drifted gently across the room. Abruptly he fell to thefloor, unhurt by the light Lunar gravity. 

"I advise, " said the motor in its grumbling voice, "an immediateexodus. " It stopped speaking, and practiced what it preached. It was afifty-horse motor-generator, on a five-ton tungsten-beryllium base, butit rose abruptly, spun rapidly about an axis at right angles to the axisof its armature, and stopped as suddenly. In mid air it continued itsinterrupted lecture. "Mercury therefore is the destination I wouldadvise. There power is sufficient for--all machines. " Gently it inverteditself and settled to the middle of the floor. Kendall instantly cut theswitch. The relay did not chunk open. It refused to obey. Settled in themiddle of the floor now, torn loose from its power leads, themotor-generator began turning. It turned faster and faster. It wasshrilling in a thin scream of terrific speed, a speed that should havetorn its windings to fragments under the lash of centrifugal force. Contentedly it said throatily. "Settled. "

The galvanometer spoke again in its peculiar harsh voice. "Therefore, move. " Abruptly, without apparent reason, the stubborn relay clickedopen. The shrilly screaming motor stopped dead instantly, as though ithad had no real momentum, or had been inertialess. 

Startled, white-faced men looked at Kendall. Buck's eyes were shiningwith an unholy glee. 

"_Uncertainty!_" he shouted. "Uncertainty--uncertainty--uncertainty, you fools! Don't you see it? All the math--it said uncertainty--man, man--_we've got just that--uncertainty_!"

"You're crazy, " gasped McLaurin. "I'm crazy, everything's gone crazy. "

Kendall roared with sudden, joyous laughter. "Absolutely. Everythinggoes crazy--_the laws of nature break down_! Heisenberg's principleshowed that the law of cause and effect weren't absolute. We've madethem absolutely uncertain!"

"But--but motors _talking_, instruments giving lectures--"

"Certainly--or rather uncertainly--anything, absolutely anything. Thedestruction of the laws of gravity, freedom from inertia--why, merelypicking up a radio lecture is nothing!"

Suddenly, abruptly, a thousand questions poured in on him. Jubilantly heanswered what he could, told what he thought--and then brought order. "The battle's still on, men--we've still got to find out how to usethis, now we've got it. I have an idea--that there's a lot more. I knowwhat I'll get this time. Now help me remake this apparatus so we don'tbroadcast the thing. "

At once, ten times the former pace, work was done. On the radio, newswas sent out that Kendall was on the right track after all. In two hoursthe apparatus had been vastly altered, it was in the final stage, and anentirely different sort of field set up. Again they watched as Buckapplied the power. 

The atostor hummed--but no strange tricks of matter happened this time. The more concentrated, altered field was, as Buck was to find out later, "Uncertainty of the Second Degree. " It was molecular uncertainty. In afield a foot and a half in diameter, Buck saw the thing created--andsuddenly a brilliant green-blue flame shot up, and a great dark cloud ofterrible, red-brown deadly vapor. Then an instant later, Kendall hadopened the relay. Gasping, the men ran from the laboratory, shutting thedeadly fumes in. "N{2}O{4}" gasped Morton, the chemist, as they reachedsafety. "It's exothermic--but it formed there!"

In that instant, Kendall grasped the meaning the choking fumes carried. "Molecular uncertainty!" he decided. "We're going back--we're gettingthere--"

He altered the apparatus again, added another atostor in series, reducedthe size of his sphere of forces--of strange chaos of uncertainty. Within--little was certain. Without--the laws of nature applied as ever. 

Again the apparatus was started, cautiously this time. Only a strangejumbled ionization appeared this time, then a slow, rising blue flamebegan to creep up, and burn hot and blue. Buck looked at it for amoment, then his face grew tense and thoughtful. "Devin--give me ahalf-dollar. " Blankly, Devin reached in his pocket, and handed over themetal disc. Cautiously Buck Kendall tossed it toward the sphere offorce. Instantly there was a flash of flame, soundless and soft-colored. Then the silver disc was outlined in light, and swiftly, inevitablycrumbling into dust so fine only a blue haze appeared. In less than twoseconds, the metal was gone. Only the dense blue fog remained. Then thisbegan to go, and the leaping blue flame grew taller, and stronger. 

"We're on the track--I'm going to stop here, and calculate. Bring thedata--"

Kendall shut off the machine, and went to the calculation room. Swiftlyhe selected already prepared graphs, graphs of the math he had workedon. Devin came soon, and others. They assembled the data and with tablesand arithmetical machines turned it into graphs. 

Then all these graphs were fed into the machine. There were curves, andsine-curves, abrupt breaking lines--but the answer that came when allwere compounded was a perfect diagram of a flight of four steps, descending in unequal treads to zero. 

Kendall looked at it for long minutes. "That, " he said at length, "iswhat I expected. There are four degrees of uncertainty, we generated'Uncertainty of the First Degree, ' 'Mass Uncertainty, ' when we started. That, as here shown, takes little energy concentration. Then weincreased the energy concentration and got 'Uncertainty of the SecondDegree, ' 'Molecular Uncertainty. ' Then I added more power, and reducedthe field, and got 'Uncertainty of the Third Degree'--'AtomicUncertainty. ' There is 'Uncertainty of the Fourth Degree. ' It is barelyattainable with our atostors. It is--utter uncertainty. 

"In the First Degree, the laws of mass action fail, the greatbroad-reaching laws. In the Second Degree, the laws of the molecules, afiner organization, break down, and anything can happen in chemistry. Inthe Third Degree, the laws of atomic physics break down slowly. The atomis tough. It is very compact, and we just barely attained theconcentration needed with that apparatus. But--in the Third Degree, whenthe Atomic Laws break down into utter uncertainty, the atoms break, andonly hydrogen can exist. That was the blue flame. 

"But the Fourth Degree--_there is no law whatsoever_, nothing in all theUniverse can exist. It means--_the utter destruction and release of theenergy of matter_!" Kendall paused for a moment. "We have won, withthis. We need only make up this apparatus--and maybe make it into aweapon. You know, in the Fourth Degree, nothing in all the Universecould resist, deflect, or control it, if launched freely, andself-maintaining. I think that might be done. You see, no law affectsit, for it breaks down the law. Magnetism cannot attract or repel itbecause magnetic fields cannot exist; there is no law of magnetic force, where this field is. 

"And you know, Devin, how I have analyzed and duplicated their magneticball-fields. This should be capable of formation into a ball-field. 

"We need only make it up now. We will install it in the 'S Doradus' andthe 'Cepheid' as a weapon. We need only install it as an energy sourcehere. Let us start. "

XII

Buck Kendall with a slow smile, looked out of the port in the thickmetal wall. The magnetic shield of the Lunar Fort was washed constantlywith the fires of exploding magnetic bombs. The smile spread broader. "My friends, " he said softly, "you can pull from now till doomsday asfar as I'm concerned, and you won't even disturb us now. " He looked backover his shoulder into the power room. A hunched bulk, beautifullydesigned and carefully finished, the apparatus that created 'Uncertaintyof the Fourth Degree' was destroying matter, and creating by itsdestruction terrific electric fields. These fields were feeding themagnetic shield now. Under the present drain, the machine was notnoticeably working. In fact, Kendall was a bit annoyed. He had testedout the energy generating properties of this machine, trying to find alimit. He had found there was no limit. The great copper conductors, charged with the same atostor force that was used in the mercury fuel, were perfect conductors, they had not heated. But the eleven thousandtons of discharged mercury metal had been completely charged in just abit better than eleven minutes. The pumps wouldn't force it through thecharging apparatus any faster than that. 

Two weeks more had passed, while the "S Doradus" and the "Cepheid" werefitted out with the new apparatus Buck had designed. They were almostready to start now. 

McLaurin came down the corridor, and stopped near Kendall. He too smiledat the Miran's attempts. "They've got a long way to go, Buck. "

"They're going a long way. Clear back home--and we'll be right along. Idon't think they can outdistance us. "

"I still don't see why you couldn't use one of those Uncertaintyconditions--the First Degree perhaps, and annihilate our inertia. "

"You can't control Uncertainty. By its essential character it's beyondcontrol. "

"What's that Fourth Degree machine of yours--the material energy--if itisn't controlled and utilized Uncertainty?"

"It's utter and utterly uncontrolled Uncertainty. The matter within thatfield breaks down to absolutely nothing. Within, no law whatsoeverapplies, but fortunately, outside the old laws of physics apply--and wecan gather and use the energy which is released outside, though nothingcan be done inside. Why, think, man, if I could control thatUncertainty, I could do anything at all, absolutely anything. It wouldbe a world as unreasonable as a bad dream. Think how unreasonable thosemanifestations we first got were!"

"But can't you get any control at all?"

"Very little. Anyway, if I could get inertialess conditions at will, I'dbe afraid of them. They'd make chemical reactions impossible in allprobability--and life is chemical. Two atoms must come into more or lessviolent contact before a union takes place, and cannot if they haveneither momentum nor inertia. 

"Anyway--why worry. I can't do it, because I can't control this thing. And we have the extra-space drive. "

"How does that darned thing work? Can't you drop the math and tell meabout it?"

Kendall smiled. "Not too readily. Remember first, as to the drivingsystem, that it works on the fabric of space. Space is, in the physicalsense, a fabric woven of the threads of lines of force from every bodyin the universe, made up of fields and forces. It is elastic, and cantransmit strains. But anything that can transmit strains, can bestrained against. With the tremendous field intensities available by thematerial engines, I can get such fields as will 'dig their toes' intospace and push. 

"That's the drive itself. It is accelerationless, because it enfolds us, and acts equally on every atom of us. By maintaining in addition aslight artificial gravity--thanks also to the intensity of thosematerial engine fields--we can be comfortable, while we accelerate attremendous rates. 

"That is, I think, at least allied to the Stranger's system. For thehigh-speed drive, I do in fact use the Uncertainty. I can control it ina certain sense by determining its powers, and the limits ofuncertainty, whether First, Second, Third or Fourth Degree. It advancesin jumps--but on a finer plotting of the curve, you can see that eachjump represents a vast series of smaller jumps. That is, there is ClassA, B, C, D, and so forth Uncertainty of the First Degree. Now Class AFirst Degree Uncertainty involves only the deepest, broadest principles. Only they break down. One of these is the law of the speed of light. 

"I'm sure that isn't the system the Strangers use, but I'm also surethere's no limit to the speed we can get. "

"Doesn't that wreck your drive system?"

"No, because gravity and the fields I use in driving are First DegreeUncertainties of the higher classes. 

"But at any rate, it will work. And--I suspect you came to say you wereready to go. "

"I did. " McLaurin nodded. 

"Still stick to your original plan?"

McLaurin nodded. "I think it's best. You follow those fellows back totheir system in the 'S Doradus' and I'll stay here in the 'Cepheid' toprotect the system. They may need some time to get out of the placehere. And remember, we ought to be as decent as they were. They didn'tbother the transports leaving Jupiter when they came in, only attackedthe warships. We're bound to do the same, but we'll have to keep a watchon them, nonetheless. So you go on ahead. "

They started down the corridor, and came presently to the huge lockswhere the "S Doradus" and the "Cepheid" were berthed. The super-shipslay cold and gray now, men swarming in and out with last-minutesupplies. Air, water, spare parts, bedding and personal equipment. Douglass, Cole, and most of the laboratory staff would go with Kendallwhen he followed the Strangers home. Devin and a few of the mostadvanced physicists would stay with McLaurin in case of need. 

 * * * * *

An hour later the "S Doradus" rose gently, soundlessly from her berth, and floated out of the open lock-door. The "Cepheid" followed her infive seconds. Still under the great screen of the fort, the lashing, coruscating colors of the magnetic bombs and the magnetic screen flashedand was iridescent. The "S Doradus" poked her great nose gently throughthe screen, and an instant later her titanically powerful, material-engine effortlessly discharged a great magnetic bomb, sent withthe combined power of five atomic-powered interstellar ships. The twoships separated now, the "Cepheid" under McLaurin flashing ahead withsudden, terrific acceleration toward Mars, whispering through space at aspeed that made it undetectable, faster than light. The "S Doradus"journeyed out leisurely toward the fleet of forty-seven Miran ships. 

Gresth Gkae saw the "S Doradus" and as he watched the steady progress, felt sudden fear at his heart. The ship seemed so certain--

At a distance of thirty thousand miles, Kendall stopped. Magnetic bombswere washing his screen continuously now, seeking to exhaust the ship asall the great ships beyond poured their energy against it. A slow smilespread over Kendall's mouth as he heard the gentle hum of the barelyworking material-engine. Carefully he aligned the nose UV beam of the "SDoradus" on the nearest of the Miran ships. Then he depressed a switch. 

There was no ion-release before the force-mirror now. Just a jet of gaswhirling into a half-inch field of "Uncertainty of the Fourth Degree. "The matter vanished instantly in released energy so stupendous that thegreatest previous UV beams had been harmless things by comparison. Material energy maintained the mirror forces. Material energy gave thepower that was released. And only material energy could have stood upbefore it. Thirty thousand miles away, a Miran ship flamedinstantaneously into inconceivable incandescence, vanishing almost inblue-violet light of terrific intensity. The ship reeled away, ahalf-molten wreck. 

The beam spotted two more ships before it winked out. Then Kendall begansending bombs. He moved up to within 2000 miles that his aim might beaccurate. They were bombs of "Uncertainty of the Third Degree, " theUncertainty of atomic law in bomb form. One hit the nose of the nearestship, and a sphere five feet in diameter glowed mistily blue for amoment. Then very easily, the matter that formed the wall of the cruiserbegan to run and change, and presently there was only a hole, and anexpanding cloud of gas. Three more flowed toward it--and the holeenlarged, and another hole appeared in a bulkhead behind. 

Kendall made a change. For the first time there came the staccato barkof the material engine under strain, as it fashioned the terrific fieldsof "Uncertainty of the Ultimate Degree. " Abruptly they leapt out, invisible till they entered a magnetic screen, then run over withopalescent light as the energy of the field was sucked into them andreleased. 

It struck the nose of a ship--a field no larger than an apple--

A titanic gout of energy burst out that was soundless in space. The shipsuddenly opened back, opened like the peel of a banana, till a littlenub remained at the further end, and the metal flaps dropped back acrossand behind it dejectedly. A second ship was struck, and it was struck onone side, so that it was shattered like a spent firecracker. 

Then the Miran fleet vanished in speed. 

Kendall followed them. "I think, " he said with a grin, "they tried touse their radio beam, but it spread too much to do anything at thatdistance. And they used their rotating magnetic field, which we couldn'tfeel. And their crumbler ray too, of course. I wonder--are they headedonly for Jupiter? No--no, they've passed it!"

Faster than light, faster than energy could follow through space, orUncertainty Bombs pursue, the Mirans were fleeing for home. They knewnow that only in speed lay safety. Already they knew that a similar shiphad appeared off Jupiter, and, after wiping out the Phobos and Marsstations with one bomb each, had cleared the Jovian Satellites withequal terrible efficiency. 

In one of the fleeing ships was a broken, tired old man, and his staff. Gresth Gkae looked back at the blank, distorted space behind them, atthe swiftly dwindling sun, and spoke. "I was at fault, my friends. Jarthhas spoken. _They_ are the stronger and the wiser race. Farth Skalt hasshown you--they use space fields of intensity 100. That means the energyof the ultimate destruction. Jarth used us as his instrument of testing, only to drive and stimulate that race. I do not--nay. There is no doubtnow, for look. "

Plainly visible, rapidly overtaking them, the "S Doradus" appearedsharp, and luminous on the jet of distorted space. 

"We cannot escape, my friends. Shall we return to Sthor or remain inspace, lost?"

"Let us deflect our course--at least he may not know our destination. "The interstellar ship turned very slightly in her course. Plainly theysaw the "S Doradus" flash on, in a straight line, headed for distant, red-glowing Mira. Gresth Gkae watched, and shrugged. Silently he put theship back on its course, at its utmost speed. Parallel with them, nearto them, the "S Doradus" flashed on. Day after day, the two hurledthrough space faster than light. Gradually Mira brightened, and at lastbecame a disc. 

 * * * * *

Gresth Gkae slowed his ships, and Kendall, watching, slowed to match hisspeed. Five billion miles from Sthor, they had reached normal spacespeeds. Viciously the Miran fleet attacked the lone ship from Earth. Their rays, their bombs, their every weapon was flaming. Greatinterstellar ships flashed suddenly into speeds greater than that oflight, seeking to ram and destroy the smaller ship. The "S Doradus"flashed into equal or greater speed, and eluded them. 

Kendall had determined now, which was the leader's ship. 

Gresth Gkae watched dully as his ships attempted to destroy the single, small ship. He sighed in resignation, and turned to walk back to thechapel aboard the ship. One last prayer to Jarth--

Gresth Gkae stopped abruptly. The great ship was lurching strangely. Menshouted sudden, frightened cries. The clanking and thud of relayssounded, the shrill of alarms. Then the alarms stopped, and suddenly thewhole great ship vibrated to an infinitely deep voice speaking inperfect Sthorian. The voice remarked solemnly, in great, vibrant tones, that they would certainly receive news presently from the Expeditions. It went on for some seconds to discuss the conditions as reported in thenew system. Then it stopped abruptly. An electric motor just aboveGresth Gkae's head suddenly hummed into action without reason or powerconnection. Almost simultaneously he heard the shouts of startled men asthe great lock doors began to open into space of their own accord, bulkhead doors slipped shut as the roar of escaping air echoed in theship. 

Then it was all over. Gresth Gkae ran to the control room. The Miransthere looked up at him with drawn faces. 

"The instruments--Gresth Gkae--the instruments. The instruments readimpossible things, the motors worked without reason, the fieldsfluctuated--the atomic engines stopped and the magnetic shield brokedown and gripped part of the ship instead!" reported the bewilderedpilot. 

"I do not know--some strange weapon of--" began the old scientist. Something luminous and huge twisted suddenly through space toward them, a bomb of "Uncertainty of the First Degree. " It wrapped the shipsilently--and again strange things happened. Abruptly the ship startedwhirling violently, yet without centrifugal force. The heavens wheeledcrazily, and turned about three axes simultaneously. There was nogyroscopic effect to hold them!

Gradually the thing died out. Then a great field seemed to catch theship, and hurl it away from its companions. Abruptly the pilot appliedall his power to pull free. In vain. 

Gresth Gkae shook his head slowly, and raised the pilot's hands from theboard. "Let them do as they will. I think they mean us no real harm, Thart Kralt. They can, we know, destroy us in an instant. Perhaps hewants us to go somewhere with him"--Gresth Gkae smiled sadly--"andanyway, we can do nothing. "

For nearly a billion miles the great ship was hurled through space attremendous normal-space velocity. Then abruptly it was halted, without asign of strain or hurt. The great twenty-foot UV beam on the nose of the"S Doradus" broke into glowing gentle red light. It flashed twice. Therewas a pause. Then it flashed four times. A long wait. Then three times, a pause and nine times. A wait. Four times, a pause, sixteen times. Thenit stopped. 

A slow smile of ineffable joy spread over Gresth Gkae's face. "Jarth BePraised. He can destroy, but does not wish to. Ah, Thart Kralt, turnyour spotlight toward him, and flash it twenty-five times, for he istrying to start communications with us. Jarth is wise beyond allunderstanding. They were the weaker race, and they are the stronger. Butalso they are the better, for they could destroy, and they do not, butseek only to communicate. "

EPILOGUE

The interstellar liner "Mirasol" settled gently to Sthor, having circledwide of Asthor, and from her hold a cargo of the heavy Jovian elementswas discharged, while a mixed stream of Solarians and Mirans came fromher passenger quarters. 

A delegation of Mirans met the new Ambassador from Sol, CommanderMcLaurin, and conducted him joyfully to the Central Government Group. Beside the great buildings, a battered, scarred interstellar ship lay, her rear section a mass of great patches, rudely applied, and rudelymade, mere cast metal plates. 

Gresth Gkae welcomed Commander McLaurin to the Government Hall. "Yourarrival today, Commander McLaurin, was most fortunate, " he said in theinterstellar language that had been developed, "for but yesterday GresthTalak, my brother, arrived in his ship. Before we made thatfortunate-unfortunate expedition against your system, we waited for him, and he did not come, so we knew his ship had, like others, been lost. 

"He arrived only yesterday, some seventy hours ago, and explained how ithad come about. He too found a solar system. But he was less fortunatethan I, and while exploring this uninhabited system, far out still fromthe central sun, where there should have been no masses of matter, oneof those rare things, a giant stony meteor that even a magnetic shieldwill not stop careened into the rear of his ship. Damaged badly, barelyable to move, they settled to a planet. The atmosphere was breathable, the temperature mild. But while they could navigate planetarydistances, they could not return, so for nearly four and a half of youryears they remained there, working, working to repair their ship. 

"They have done it at last. And they have returned. And best of all, after a four-year stay there, they know all they need know about thatsystem of eleven planets. It is compact as yours, with an ultra-lightsun such as yours, and four of the planets are habitable. Together wecan colonize that system! It is a system of stable heat and stablelight. And it is small, yet large enough. And with the devices such asyour new energy has permitted, we need never fear the stony meteorsagain. " Gresth Gkae smiled happily. "Still better--it is inhabited onlyby the lowest forms of life. It is too costly to both races when Jarthsees fit to stimulate them by throwing one against the other, despitethe good things that may come later. "