A collection of original science fiction stories. Kuttner, Henry. "A Cross of Centuries" Kornbluth, C. M. "The Advent On Channel Twelve" Leiber, Fritz. "Space-Time for Springers" Wilson, Richard. "Man Working" del Rey, Lester. "Helping Hand" deFord, Miriam Allen. "The Long Echo" Cooper, Edmund. "Tomorrow's Gift" Knight, Damon. "Idiot Stick" Gunn, James E. "The Immortals"