Plot summary

Psychiatrist Dr. Parson (Danny Rogers) is struck from behind by an unseen assailant, while sitting outside his beachfront home. Within moments, his daughter, Christie (Mary McDonough), finds his body floating in the swimming pool.Weeks later, a young man named Josh (Denis Mandel) trespasses at the warehouse of his former employer, mortician Hank Andrews (Christopher George). Assisted by his friend, Greg Stevens (David Wallace), Josh attempts to steal a pair of tires as compensation for unpaid back wages. The boys are briefly distracted as they witness the mortician conducting an occult ritual, which includes Eve Parson (Lynda Day George), the doctor's widow. While rolling the tires toward the exit, Josh is accosted by a masked killer, who stabs him repeatedly with a trocar, a tool used in embalming. The killer loads the body into Greg's van, and drives away.That evening Greg is given a ride home by his girlfriend, Christie, and as they kiss goodnight, the attacker approaches them, but retreats when Greg's parents appear. The following day, Sheriff Duncan (Bill Conklin) recovers the van, then questions Greg about Josh's disappearance and the boys' trespassing at the warehouse. While Greg admits guilt, he also tells the sheriff of Hank's ritual, which the mortician strongly denies. The sheriff releases Greg with a warning and continues his search for Josh.Meanwhile, Christie tells her mother, Eve, that someone followed her home, but her concern is dismissed as paranoia brought on by her father's "accidental" death. Christie insists that his death was no accident, and criticizes Eve's complacency. That night, Christie envisions her father's murder in a dream, then sleepwalks through the house and into the swimming pool. When Christie is wakened by a disembodied voice whispering her name, she runs screaming into the house, where she sees a masked face watching her through a window. Although Eve tries to comfort Christie by telling her that she imaged everything, the girl believes herself to be the next victim of her father's killer, and accuses her mother of trying to drive her insane.The following day, Christie and Greg visit Dr. Parson's grave, and encounter Paul Andrews (Bill Paxton), the mortician's son, who recently lost his mother to suicide. Christie and Greg both agree that the eccentric Paul has gotten "weirder" in recent weeks, and place the blame on Hank for forcing the boy to work as an embalmer.One evening, while Greg and Christie are alone in her house, they are subjected to frequent interruptions in electrical and telephone services. When Eve is told of the phenomenon, she again blames her daughter's overactive imagination. Later, the couple suspects Eve and Hank of being romantically involved, and follow them to the warehouse, where the mortician conducts a seance to contact the spirit of Dr. Parson. Paul observes Christie and Greg from a distance, but says nothing as they leave the building.When the couple returns to the Parson home, Christie asks Greg for a moratorium on their relationship until she can better manage her fears. That night, she has another dream about her father's death, and resumes sleepwalking, this time arming herself with a knife. The masked figure appears outside the window, asking to touch her, and she plunges the knife through the glass, shocking herself back into consciousness. Christie seeks comfort from her mother, who explains that her late husband was Paul's psychiatrist. The boy developed a psychotic obsession with Christie following his mother's death, prompting Dr. Parson to recommend he be institutionalized. Based on these facts, Christie deduces that Paul killed her father. She apologizes to Eve for her erratic behavior, and following an embrace, the women return to their bedrooms.While Eve sleeps, the stalker stabs her to death, then pursues Christie around the house. Believing she has evaded the killer, Christie calls police, but is interrupted as her stalker grabs her from behind and reveals himself to be Paul. He renders her unconscious with chloroform and drives her to the mortuary. Unable to stay away, Greg returns to the Parson home as Paul drives away with Christie and her mother's body. He follows Paul to the mortuary, where the killer injects Christie with a sedative and dresses her in a wedding gown.Hank arrives moments later and accuses Paul of stalking Christie and killing her father. Paul states that Dr. and Mrs. Parson needed to be punished for opposing his plan to marry Christie. When Hank orders his son to surrender to the sheriff, Paul responds by stabbing him.Greg enters the mortuary to find Paul declaring that he and Christie are to be married, and standing over Eve and Hank's bodies. He locks Greg in the embalming room, and drives Christie and the two corpses to the warehouse for a wedding ceremony. Greg escapes the mortuary, arms himself with an ax, and follows Paul to the warehouse.Surrounded by the preserved bodies of his victims, Paul pretends to conduct a Mozart symphony, then tells the body of his mother that he "faked" her death to protect her from being institutionalized for her multiple suicide attempts. As Paul is about to cut Christie with a scalpel, Greg threatens the killer with his ax, but Paul knocks the weapon out of his hands. As Paul is about to stab Greg, the sleepwalking Christie grabs the ax and sinks the blade into Paul's back, killing him. She sobs as she regains consciousness, and Greg assures her the danger has passed. In the final shot, Mrs. Andrews (Donna Garrett) suddenly springs to life and runs at the couple with a knife in her hand.