 is a science fiction short story by American writer Isaac Asimov.It was first published in the June 1951 issue of "Astounding" and was reprinted in science fiction anthologies such as "Beachheads in Space" (1952) and "The Great SF Stories #13 (1951)" (published in 1985), as well as in Asimov-only collections such as "Through a Glass, Clearly" (1967), "Nightfall and Other Stories" (1969).and "Robot Dreams" (1986).