Psycho

Marion Crane, a secretary in Phoenix, impulsively steals $40,000 in cash from her employer's client and goes on the run, planning to start a new life with her boyfriend Sam Loomis. Caught in a rainstorm, she pulls off the highway and checks into the isolated Bates Motel — the only other presence being the motel's owner, Norman Bates, a gentle and nervous young man with a taxidermy hobby, and his reclusive mother in the house on the hill above.

Norman and Marion share a meal in his parlor, surrounded by his stuffed birds. He tells her he feels trapped by his life and his mother. She suggests, gently, that he put her somewhere. He bristles. She returns to her room, reconsidering her theft, planning to return the money in the morning. That night, a figure in a dress and wig stabs her to death in the shower. Norman discovers the body and, frantic to shield his mother from suspicion, cleans the room, wraps Marion in a shower curtain with her belongings and her car, and sinks everything in the nearby swamp. The $40,000 disappears with her.

Marion's sister Lila and her boyfriend Sam hire a private investigator named Arbogast to find her. He traces her to the Bates Motel and is murdered on the stairs of the house before he can report back. When Arbogast also vanishes, Lila and Sam consult the local sheriff — who tells them, puzzled, that Norman Bates's mother has been dead for ten years, poisoned by Norman himself in a jealous rage over a lover, then preserved so he would never have to lose her.

Lila and Sam visit the motel. Sam keeps Norman occupied while Lila searches the house. In the fruit cellar she finds Mrs. Bates — a mummified corpse in a rocking chair. Norman arrives in his mother's dress and wig, knife in hand. Sam subdues him.

A psychiatrist explains what happened: Norman developed a split personality, assuming his mother's voice and identity whenever his guilt or attraction to a woman became unbearable. In those moments, he was her — and she eliminated the threat. The final image is Norman alone in a cell, his mother's voice narrating his thoughts, her face briefly superimposed over his smile.