MEN OF TREASON Dan Fowler, Ace of the F.B.I., battles to blow the lid off a racket that threatens our Nation's war effort—and teaches traitors who gamble on American lives that justice holds the trump hand! THE CROWN OF MURDER Following the dangerous trail of an international gem robbery studded with corpses, the Ace of the F.B.I. is plunged into a web of death spun by a master of crime! Dan Fowler and Larry Kendal brave grim odds in an all-out battle for justice.