Synopsis

Superman must find out the identity of the mysterious gang leader known as the Unknown X who has organized one of the most thorough criminal organizations Metropolis has ever seen.

Written By:

Bill Finger Henry Boltinoff Jerry Siegel Gardner Fox Ed Moore Jack Lehti

Pencils:

Bob Kane Stan Aschmeier Henry Boltinoff Howard Purcell John Wentworth Harry Lampert Paul Norris Ed Moore Don Cameron Jack Lehti Joseph Sulman Eddie Winiarski Paul Henry Cassidy

Inks:

Bob Kane Stan Aschmeier Henry Boltinoff Howard Purcell Harry Lampert Ed Moore Jack Lehti Joseph Sulman Leo Nowak

Cover By:

Fred Ray