As Norman tells his story on the radio, he reveals the origins of his madness, including his unhealthy relationship with his mother, Norma. Flashbacks show how Norma had a controlling and emotionally abusive effect on Norman, which ultimately led to his violent behavior.
As Norman prepares for the arrival of his child, he becomes increasingly anxious about his ability to be a good father and avoid repeating the cycle of abuse that he experienced with his own mother. He also begins to experience hallucinations and vivid dreams about his mother, who seems to be urging him to commit murder once again.
Meanwhile, Fran begins to suspect that "Ed" may actually be Norman Bates and continues to press Dr. Richmond for more information about his former patient. As the tension mounts, it becomes clear that Norman's inner demons are still very much alive and threatening to destroy everything he has built in his attempt to lead a normal life.
In the climactic finale, Norman's fears are realized as he experiences a violent relapse and a final showdown with his own demons and those who would seek to expose him. The movie ultimately serves as a haunting meditation on the nature of madness and the destructive power of family dysfunction.