Norman Bates (Perkins) has finally been judged mentally sound and released from the mental institution where he has been for 22 years. Once out, he eventually falls in love with Mary (Tilly). But Lila Loomis (Miles), the sister of Marion Crane who was murdered in the shower 22 years before, protests fiercely over his release and wants him put back in the institution for life. Then Norman sees his mother in the window of the Bates house and the murders start happening again. But this time it isn't Norman... or is it?