Norman Bates is released from the mental hospital, after having been re-incarcerated at the end of Psycho III; after spending several years there, he is judged rehabilitated again. Norman is now married to a young psychiatrist named Connie and is expecting a child. Norman secretly fears that the child will inherit his mental illness, so he must seek closure once and for all.
Radio talk show host Fran Ambrose is discussing the topic of matricide with her guest Dr. Richmond, Norman's former psychologist. Norman calls the show, using the alias "Ed", to tell his story.
Norman's narrative is seen as a series of flashbacks set in the 1940s and 1950s, some slightly out of order. When Norman is six years old, his father dies, leaving him in the care of his mother, Norma. Over the years, Norma (who is implied to suffer from schizophrenia and borderline personality disorder) dominates her son, teaching him that sex is sinful and dressing him in girl's clothes as punishment for getting an erection in her presence.
The two live in contented isolation at the large house as if there is no one else in the world until, in 1949, she becomes engaged to a brutish man named Chet Rudolph. Driven over the edge with jealousy and suffering from Norma and Chet's constant abuse, Norman kills both of them by serving them poisoned iced tea, then steals and preserves his mother's corpse. He develops a split personality in which he "becomes" his mother to suppress the guilt of murdering her; whenever this personality takes over, it drives him to dress in his mother's clothes, put on a wig, and talk to himself in her voice. As "Mother", he murders two local women who try to seduce him during their stay at his newly opened motel.
In the present day, Dr. Richmond realizes "Ed" is Norman and tries to convince Ambrose to trace the calls. Richmond's worries are dismissed. Norman fears he will go insane and kill again. He tells Fran that Connie got pregnant against his wishes and that he does not want to create another "monster". He then tells Fran he realizes that his mother is dead, but he fears that his mother may repossess him and kill Connie "with my own hands, just like the first time."
Norman takes his wife to his mother's house and does attempt to kill her, but Connie reassures Norman that their child will not be a monster, and he drops his knife. Connie forgives him. Finally, Norman impulsively sets fire to the house where all his unhappiness began. As he tries to escape the flames, he hallucinates that he sees his victims, his mother and eventually himself preserving her corpse. Norman barely flees the burning house alive.
He and Connie leave the next day. Norman happily proclaims, "I'm free," indicating that his mother will never again haunt his mind and drive him insane. Then, the wooden doors of the house cellar close on the rocking chair that continues to rock, at which point "Mother" screams for Norman to release her before the sound of a baby crying is heard.
What is the name of Norman's wife?
Connie