Written by Jack Kirby and Dave Wood with art and cover by Kirby and others and an introduction by Paul Kupperberg! The Challengers were test pilot Ace Morgan, daredevil/mountain climber Red Ryan, heavyweight boxing champ Rocky Davis, and Professor Haley, a scientist specializing in underwater exploration -- four men who barely survived the crash of a small aircraft and considered themselves to be living on borrowed time! After avoiding such a devastating fate, they dedicated themselves to a life of harrowing adventures, all in the name of good. Nothing was deemed too dangerous for the Challengers -- after all, they should have been dead already! The fearsome foursome faced the impossible and the unimaginable at every turn -- don't miss this chance to relive their earliest adventures! 168-page hardcover that collects SHOWCASE #6-7, 11-12, and CHALLENGERS OF THE UNKNOWN #1-2, circa 1957-1958.