And so I says to myself, says I, give me a good husky band of Boy Scouts! They'll do the job if it can be done! Case Canfield, caretaker, sat back in a patched chair in the dusky, unoccupied office of the Labyrinth mine and addressed himself to four lads of seventeen who were clad in the khaki uniform of the Boy Scouts of America. Those of our readers who have read the previous books of this series will have good cause to remember George Benton, Charley ("Sandy") Green, Tommy Gregory and Will Smith. The adventures of these lads among the Pictured Rocks of Old Superior, among the wreckers and reptiles of the Florida Everglades, in the caverns of the Great Continental Divide, and among the snows of the Hudson Bay wilderness have been recorded under appropriate titles in previous works. The four boys were members of the Beaver Patrol, Chicago. Will Smith was Scoutmaster, while George Benton was Patrol Leader. They wore upon the sleeves of their coats medals showing that they had passed the examination as Ambulance Aids, Stalkers, Pioneers and Seamen.