Chan Shou-Ching is a beautiful introverted young woman who works as a police psychologist. She's troubled by a recurring dream about her father mysteriously leaving her when she was ten. One night, she has a nightmare about a devil-worshiping psychopath brutally killing a woman. Her roommate, colleague and best friend, Rose, is dating a facetious, womanizing, inept, cowardly cop called Ka-Ming. The girls witness Ka-Ming's tough partner Mo Ti Nam brutally taking out an armed gang in a restaurant, so Ching decides to investigate him for police brutality. That's when the killer from her dream contacts her and presents himself as Judas, a supernatural clairvoyant satanic serial killer who must prove to her that she is the Devil's daughter. If she accepts this as truth, she will become the Antichrist and destroy the world. Nam, Ka-Ming and Ching's priest who taught her about Christianity in her youth try to stop the killer before it's too late.