In Los Angeles, California, police detective Danny O’Brien has a nightmare related to his apprehending serial killer Simon Moon, known as “The Terror,” three years earlier: beneath the Santa Monica Pier, Danny and his partner, Dwight, find Moon’s hideout and the bodies of his female victims. As Danny follow Moon’s tracks in the sand, the killer attacks and nearly drowns Danny. Danny climbs a ladder to escape, followed by Moon, but the killer falls and is knocked unconscious. When Dwight and backup officers arrive, they give Danny the nickname, “Hero,” and Moon is sent to Camden State Maximum Security Hospital. Danny is awakened by a telephone call from his pregnant girl friend, Kay Kennedy, reminding him that he agreed to help move her belongings into his apartment. He tells Kay that his nightmares relating to Simon Moon are starting again. As his former therapist, Kay insists the dreams will go away in time. At Camden State Hospital, Dr. John Highwater discovers Simon Moon has escaped from his cell and stolen a laundry van. Moon drives the van off a cliff into a river, but his body is not found. At the newly renovated Wiltern Theatre, employee Betsy Hammond goes to the restroom. Simon Moon emerges from an air vent. After breaking Betsy’s neck, Moon drags her body to his hideout above the theater’s false ceiling. Meanwhile, Danny and Kay learn they are having a daughter. Danny asks Kay if she wants to get married, but she does not feel ready. In the evening, the Wiltern holds a premiere for actress Ginger Franks’s new film. Ginger goes to the restroom to retouch her makeup, but Moon kills her. Ginger’s body is found in a park near the theater. At the mayor’s insistence, Danny is ordered to investigate Ginger’s murder. Seeing her neck was broken, Danny believes Simon Moon is alive. He meets with Dr. John Highwater, and learns that Moon kills on instinct like an animal, and has a drive to take his victims to a place where he feels safe. Danny visits Moon’s former hideout at the pier. His partner, Dwight, arrives and informs Danny that Betsy’s father reported to police that his daughter went missing while working at The Wiltern. At City Hall, Danny informs the mayor and his assistant, Sal Copelli, that Simon Moon is killing women inside the theater. The mayor agrees to have an officer remain at the theater at all times to search for Moon. After an evening out, Danny and Kay arrive at The Wiltern to see Danny’s friend and coworker, Bill Robinson. While Danny updates Robinson on the return of Simon Moon, Kay goes to the restroom. However, Danny insists they go home, but Kay goes into labor, and Danny drives her to the hospital. As Kay gives birth, Bill Robinson is murdered by Moon and his body placed outside the theater. When informed of Bill’s death, Danny and Dwight go to the theater, and find the unlocked air vent in the women’s restroom. Climbing inside, Danny makes his way above the auditorium, but sees no sign of Simon Moon. In the morning, Danny looks over The Wiltern’s blueprints and finds a hidden prop room he missed. Returning to the theater, Danny finds Moon’s hideout, and the bodies of several victims. Moon attacks Danny. Leading Moon to the roof outside, Danny kills the killer by throwing him through a skylight to the theater floor. Afterward, Danny arrives at the hospital with a priest. Seeing the priest, Kay agrees to marry Danny.