In 1964, Playboy magazine approached several science fiction writers to create short-short stories based on a photograph of a clay head without ears. The selected stories--Arthur C. Clarke's "Playback", Frederik Pohl's "Lovemaking", and Thomas M. Disch's "Cephalatron" (later "Fun with Your New Head")--were published in the December 1966 issue. Asimov's story, on the other hand, was rejected, so he submitted it to the Magazine of Fantasy and Science Fiction, where it was published in April 1965. It has since been anthologized several times and was included in Asimov's collection Nightfall and Other Stories (1969).

In the very distant future - about a trillion years in the future - humans have long since abandoned physical form and they exist as energy entities spanning space. The results are quite powerful.

This is the story of how two of these entities, known only as Ames and Brock, tire of artistic competitions using manipulations of energy and decide to look for a creative way to manipulate mass.