Clement Dunne buries the half-naked body of a female murder victim in a shallow grave on a southern California beach, then returns to his sparsely furnished single apartment where he cuts out the face of “Judy,” Miss January from a men’s magazine, then draws a circle around the face of “Jackie,” Miss March. At her apartment, Jackie Carroll awakens to the ring of her alarm clock, puts on her white nurse’s uniform, and drives to West Park Hospital in her late model Cadillac convertible. There, she receives a telephone call from Clement, asking where she got the car, since he has never seen her drive it before. Jackie recognizes the voice of the phone-stalker who has been harassing her as he rails that exposing her body is filthy, and dirties the minds of others. When she leaves for the day, Clement follows Jackie in his Ford Falcon station wagon. She stops for gas, and while her tank is being filled, she is approached by a young woman named Linda Williams, who says that she has been waiting three hours for her boyfriend to pick her up and take her to Barstow, California. Jackie offers the young woman a ride, as she is on her way to the mountains see about a nursing job. As Linda accepts Jackie’s offer, three rather disreputable characters observe from afar and cheer as the two women drive off. Clement has also been watching and continues following Jackie when she pulls out of the gas station. Arriving at Camp Manachee, Jackie goes to the office and asks to see Dr. Hudson, but is told by Mrs. Walker, who runs the camp with her husband, Ed, that the doctor was called away on an emergency and will not return before Sunday afternoon. Mrs. Walker asks if she wants to reschedule the appointment, but Jackie says she will stay with at her aunt’s vacation house in the area until Dr. Hudson returns. Linda agrees to stay with Jackie at her aunt’s, and Jackie promises to drive her to the bus station in the morning. Ed Walker overhears the young women’s conversation and seems greatly curious about Jackie. That night, as Jackie and Linda sleep, the three disreputable characters make their presence known to Linda, who is associated with them, and she lets them into the house. When Jackie demands to know who the people are, Linda introduces them as her boyfriend, Tim, and her two friends from Barstow, Donna and Rita, and asks if Jackie minds if they spend the night? Jackie agrees to let them stay, but the group terrorizes her with loud partying during the night and physical abuse in the morning. When she attempts to retrieve her car keys from her purse so she can go to the police, she discovers that Tim has taken them. He threatens to rape her, but is startled when someone comes to the door. Tim tells Jackie to get rid of the visitor, Ed Walker, who says he is on his way to the store and stopped by to see if Jackie needed anything. Jackie tells him no, and Ed leaves; however, her houseguests continue their campaign of terror until they get bored. Before they leave, Tim insists on consummating his postponed rape. However, Jackie fights him off and escapes. The four intruders chase Jackie through the woods, and she finds herself at Camp Manachee where Clement is now staying. Jackie rouses the Walkers in the camp office, and they bring her inside. Ed Walker calls the police, and Mrs. Walker suggests they put Jackie up in room twelve, next to “that man who came in yesterday.” After Ed takes Jackie to the room, Clement attempts to open her door, but is thwarted when Ed returns and asks what he is doing. Mrs. Walker demands that Ed get Jackie out of the camp the next morning, and he takes her back to her aunt’s house, where he attempts to seduce her. Since Jackie is beyond “putting up a fight,” Ed Walker loses interest and leaves. Clement comes in, offering to help Jackie, and she recognizes the voice of her phone-stalker. With no fight left in her, Jackie cannot escape, and Clement slits her throat, then cuts her face from her picture in the magazine when he returns to his apartment. Clement now turns his attention to “Charly,” Miss May. As Charly races off for a boat trip to an island where she will be participating in a centerfold photo shoot, Clement pursues her. “Charly” joins a group of people, including photo director Melissa and her sometime lover, Perry; Sam, a photographer, and two other models, Glory and Sandi, who travel to a house on an isolated island. Clement steals a boat and follows. On the island, Clement enters Glory’s bedroom, but does not kill her. Instead, he stalks Sandi, Charly’s roommate, who hears a sound as she returns to their room after a tryst with Perry. Sandi goes to the cliff overlooking the ocean seeking the person who made the sound, and is killed by Clement. Glory discovers her body the next morning. That night, Clement returns to the house, but is discovered by Perry, who is killed by the intruder. The rest of the visitors believe that Melissa killed Perry in retaliation for his one night stand with Sandi. Sam sends the women back to their rooms, but as he looks for the killer, Clement kills Melissa. Sam gives Charly his pistol for protection, and goes in search of a boat so he and the remaining women can escape; but he, too, is killed by Clement. Charly goes to her room to get some blankets, and when Glory enters the room, she mistakes the girl for the killer and accidentally kills her. As Charly runs screaming from the house, Clement grabs her and slits her throat. Police are baffled at how all those known to be on the island are dead. Clement now turns his attention to Vera Porter, a flight attendant who has posed for centerfold photos. At Vera’s apartment complex, Clement confuses Vera’s friend, Patsy, for the centerfold model and kills her by mistake. Police tell Vera that the killer is likely stalking her. The following morning, Clement calls Vera. In turn, she phones the police and finds Sergeant Garrett off duty. In an effort to escape her stalker, Vera leaves town. Through a ruse, Clement discovers where she has gone. When Vera returns to her hotel room after a walk on the beach, she finds yellow roses in her room and receives a telephone call from Clement. Vera gets into her car to return to Los Angeles, and Clement follows. Her car breaks down, but before Clement can get to Vera, two sailors, returning to their base in San Diego, drive up and offer her a ride. Clement pursues them. At a rest stop, the sailors drug Vera’s beer when she goes to the restroom, and, as a result, she loses her inhibitions. They take her to a hotel and rape her. In the morning, after the sailors have left, Clement and the hotel manager check Vera’s room and Clement offers her a ride. They stop at a gas station, where Vera goes to call a tow truck to pick up her car, and Clement buys a knife at a nearby store. Back in his car before Clement returns, Vera finds the pinup magazine with the models faces cut. Realizing that Vera has found him out, Clement holds the knife to her throat and drives her to a remote location, where he asks if she will stand naked in front of him an let him make love to her? To save her life, Vera says yes, and Clement responds that he knew she was “unclean.” When he takes out his razor, she knees him in the groin and runs away. In the ensuing chase, Vera picks up a rock and throws it at Clement, stunning him and breaking his glasses. Vera gets back to Clement’s car, but he has taken the keys. However, the knife is on the front seat, and when he catches up to her, Vera stabs Clement to death. With his dying breath he says he only wants to help her.