Psycho is an American 1960 suspense/horror movie directed by Alfred Hitchcock, from the screenplay by Joseph Stefano. The film is based on the novel of the same name by Robert Bloch, which was in turn inspired by the crimes of Wisconsin serial killer Ed Gein. There's also a 1998 remake of this film
The story starts with Marion, In need of money to marry her boyfriend Sam Loomis, Marion Crane steals $40,000 from her employer and flees Phoenix, Arizona by car. While en route to Sam's California home, she parks along the road to sleep. A highway patrol officer awakens her and, suspicious of her agitated state, begins to follow her. When she trades her car for another one at a dealership, he notes the new vehicle's details. Marion returns to the road but, rather than drive in a heavy storm, decides to spend the night at the Bates Motel.
Owner Norman Bates tells Marion he rarely has customers because of a new interstate nearby and mentions he lives with his mother in the house overlooking the motel. He invites Marion to have supper with him. She overhears Norman arguing with his mother about letting Marion in the house, and during the meal she angers him by suggesting he institutionalize his mother. He admits he would like to do so, but does not want to abandon her.
Marion resolves to return to Phoenix to return the money. After calculating how she can repay the money she has spent, Marion dumps her notes down the toilet and begins to shower. An anonymous female figure enters the bathroom and stabs her to death. Finding the corpse, Norman is horrified. He cleans the bathroom and places Marion's body, wrapped in the shower curtain, and all her possessions — including the money — in the trunk of her car and sinks it in a nearby swamp.
Shortly afterward, Sam is contacted by both Marion's sister Lila and private detective Milton Arbogast, who has been hired by Marion's employer to find her and recover the money. Arbogast traces Marion to the motel and questions Norman, who unconvincingly lies that Marion stayed for one night and left the following morning. He refuses to let Arbogast talk to his mother, claiming she is ill. Arbogast calls Lila to update her and tells her he will contact her again after he questions Norman's mother.
Arbogast enters Norman's house and at the top of the stairs is attacked by a figure who slashes his face with a knife, pushes him down the stairs, then stabs him to death. When Arbogast does not call Lila, she and Sam contact the local police. Deputy Sheriff Al Chambers is perplexed to learn Arbogast saw a woman in a window, since Norman's mother died ten years ago. Norman confronts his mother and urges her to hide in the cellar. She rejects the idea and orders him out of her room, but against her will Norman carries her to the cellar.
Posing as a married couple, Sam and Lila check into the motel and search Marion's room, where they find a scrap of paper in the toilet with "$40,000" written on it. While Sam distracts Norman, Lila sneaks into the house to search for his mother. Sam suggests to Norman that he killed Marion for the money so he could buy a new hotel. Realizing Lila is not around, Norman knocks Sam unconscious and rushes to the house. Lila sees him and hides in the cellar where she discovers the semi-preserved and mummified body of Norman's mother. Wearing his mother's clothes and a wig and carrying a knife, Norman enters and tries to attack Lila, but she is rescued by Sam.
After Norman's arrest, forensic psychiatrist Dr. Fred Richmond tells Sam and Lila that Norman's dead mother is living in Norman's psyche as an alternate personality. After the death of Norman's father, the pair lived as if they were the only people in the world. When his mother found a lover, Norman went over the edge with jealousy and murdered both of them. Consumed with guilt, he tried to "erase the crime" by bringing his mother back to life in his mind. He stole her corpse and preserved the body. When he is "Mother", he acts, talks, and dresses as she would. Norman imagined his mother would be as jealous of a woman to whom he might be attracted just as he was of his mother's lover, and so "Mother" kills any woman he has feelings for; when Norman regains consciousness, he believes that his mother has committed the crime, and covers up for her. It is implied that Norman is responsible for the unsolved disappearances of two young girls. Richmond concludes that the "Mother" personality has now taken complete control of Norman's mind.
In the final scene, Norman sits in a cell, thinking in "Mother"'s voice. In a voiceover, "Mother" explains that she plans to prove to the authorities she is incapable of violence by refusing to swat a fly that has landed on her hand. The final shot shows Marion's car being recovered from the swamp.
