Fantastic: August 1956 (Volume 5, Number 4)
Illustrations by Virgil Finlay, (John) Giunta, and at least 3 others (uncredited.) Cover by Edward Valigursky.

Contents: "Guardian of the Crystal Gate" by Robert Silverberg (novelet - based on cover)
"The Long Forgotten" by Henry Still
"O' Captain, My Captain" by Ivar Jorgensen
"Growing Pains" by Robert Arnette
"The Slow and the Dead" by Robert Randall (=Robert Silverberg+Randall Garrett; novelet)
"Revolt of the Synthetics" by Ralph Burke.

Edited by Howard Browne.