The man who folded himself (1973)

An inherited time belt allows Dan Eakins to meet other versions of himself, making identity as much of a puzzle as cause and effect. Gerrold follows the premise into desire, loneliness and the strange limits of being one's own most important companion. This short, conceptually concentrated novel turns inward, with self-encounter taking the place of a broad historical adventure. Its adult treatment of sexuality belongs to the argument about who a person can become.