SF/Horror anthology. This series was one of five SF anthologies launched in a six-month period (cover dates January 1952–June 1952), increasing Marvel's SF line from seven to twelve books. It was also one of five such anthologies cancelled together, reducing Atlas's SF line from thirteen books to eight. It was re-launched as one of eight SF anthologies launched in an eight-month period (cover dates October 1955–June 1956), increasing Marvel's SF line from eight to sixteen books. This book ran until the collapse of Atlas's distributor and the subsequent restructuring known as the "Atlas Implosion".