It first appeared in the November 1956 issue of "Science Fiction Quarterly" and was anthologized in the collections "Nine Tomorrows" (1959), "The Best of Isaac Asimov" (1973), "Robot Dreams" (1986), "The Best Science Fiction of Isaac Asimov" (1986), the retrospective "Opus 100" (1969), and in "Isaac Asimov: The Complete Stories, Vol.