Trapped in a cave, five men cut the arm off of another companion in order to ward off starvation. After they are saved, their victim seeks revenge on them one by one.
Norman Bates is again released from the mental hospital he was placed in at the end of Psycho III after serving another few years and is apparently rehabiliated for the second time. Norman is now married to a young nurse named Connie and is expecting a child. However, Norman fears that the child will inherit his mental illness. Meanwhile, Fran Ambrose is a radio talk show host who is discussing the topic of matricide with guest Dr. Richmond, Norman's former psychologist. The radio station receives a call from Norman, who uses the alias "Ed" to tell his story.