Five survivors of a global war are kept alive inside a mammoth computer called AM, which is supremely intelligent and self-aware. It is descended from several Allied Mastercomputers that were developed to fight the massive war as it became more and more complicated. The four men and one woman have been inside the computer for 109 years.

In his previous life, Gorrister had been a conscientious objector who took part in peace marches and planned for the future. The computer transforms him into someone who cares about nothing. Benny, who had been a homosexual college professor, is redesigned as an insane chimpanzee-like being with enormous genitals. Another man has been renamed "Nimdok" by the computer, which the narrator, Ted, explains, "amused itself with strange sounds." This man spends long periods of time alone in the darkness. The others do not know what AM does to him...