Simon Dykes is a successful artist about to open another big show of his work in London. A week before the opening, he goes out to a bar with his colleagues, indulges in drugs, has sex with his girlfriend, and falls into an uncomfortable sleep with bizarre dreams. He wakes up in a world where every person is a chimpanzee and where humans are kept in zoos or are experimented on in labs, and the few humans surviving in the wild are close to extinction.
Terrified and dismayed, he is taken to a psychiatric ward where the chimpanzee doctors try to help him overcome his "delusions" that he is actually a human. They eventually turn to Dr. Zack Busner, an alpha male, theoretical renegade and media star, as well as a maverick drug researcher, "anti-psychiatrist," psychoanalyst, and clinical psychologist. Together they try to understand the root of Simon's delusion and return Simon to his sanity and "chimpunity."
