The Thanatos Syndrome (1987) was Walker Percy's last novel. It is a sequel to Love in the Ruins. Set in the near future in Feliciana, it tells the story of an imprisoned psychiatrist who is freed and returns to his town with the active members demonstrating new mysterious behaviors. He suspects that something or someone is making everyone in his town crazy and reversing them to be like primitive apes.

Walker Percy, OblSB was an American writer whose interests included philosophy and semiotics. Percy is noted for his philosophical novels set in and around New Orleans; his first, The Moviegoer, won the National Book Award for Fiction.