The film revolves around a series of murders of young women in the southern California area. The opening scene features an unnamed blonde woman (Betty Boatner) running along a mountain road, wearing only her undergarments. She is clearly scared for her life. She enters a city park and manages to reach a telephone booth. Her attempt to escape her assailant ends in failure, when the man also reaches the booth. He quickly kills her and leaves her corpse next to a lake. The corpse is soon discovered by visitors of the park.
The scene shifts to a police station, where Police Lieutenant Matt Carson (Kenne Duncan) receives a phone report on the latest murder. He instructs subordinate Officer Kline (Fred Mason) to gather information from the witnesses who called in the discovery of the body. Then he summons his associate Sergeant Randy Stone (Duke Moore) and they head out towards the crime scene. They take note of the youthful appearance of the victim and suspect a connection to the "smut picture racket".
The next scene takes place in the film studio of pornographic director Jaffe (Harry Keatan), an elderly man who is somewhat elfin in appearance. Jaffe is currently shooting a scene involving three women posing for the camera. He fusses over the details of the scene he is shooting, in a scene both depicting and mocking his artistic pretensions. His superior Johnny Ryde (Carl Anthony) interrupts him to bring orders from their boss, Gloria Henderson (Jean Fontaine). She wants their inventory moved to a safer location. Jaffe promises to do so after completing of his shooting. He never actually finishes, since Carson leads a police raid into the studio. All participants in the shooting are arrested, and the inventory of films passes into police custody.
Back at the police station, Carson and Stone are berated by their superior, who demands quicker action in exposing the racket. Afterwards the two officers are visited by local businessman Mr. Romaine (Harvey B. Dunn), who demands to know why are taxpayers' money wasted in persecuting harmless deviances such as pornography. In his view, they should be preoccupied with more serious crimes and with the gangs of young hoodlums roaming the streets. In response, Carson claims that the dirty picture racket is connected to major crimes. He then reveals images of the murder victims, and explains the connection between them working for the racket and their violent deaths. He then asks the shocked Romaine if he has a daughter. As he exits the door to leave, the visibly shaken Romaine explains that he has two daughters.
The next scene takes place in the suburban house of Gloria Henderson. Gloria is visited by Johnny Ryde, who informs her of the recent police raid. The conversation shifts to Shirley, a person permanently silenced by Dirk. This is the first time the name of the killer is revealed in the film. The conversation also reveals that Shirley had learned too much about the inside operations of Gloria's organization and was attempting to blackmail them. Johnny states that he is worried about Dirk himself, since he clearly enjoys using his knife.
The conversation next moves to another operation of the pornography ring. They have been peddling bondage photos to high school kids, but these young customers have started demanding newer material.
The scene shifts to a hangout for the teenage crowd, Jake's Pizza Joint. Teen customers are depicted happily dancing and eating. Then two young man approach each other, with switchblades in their hands. A fight begins, and Dirk Williams (Dino Fantini) is seen observing from afar. The fight is taken outside and evolves into a street fight attracting onlookers. Inside Jake, the owner, finds time to negotiate the purchase of more smut pictures from Janet, an agent of the pornography ring. He complains, however, about the inventory of photos he already has. Claiming that copies are already owned by everyone from ages 7 to 70, so finding new customers is hard. The fight outside attracts the attention of the police, so Jake and others are arrested. The two street fighters are revealed to be low-level smut peddlers, who were fighting over turf area.
Later, Janet leads three other women into attacking Clauson, a distributor of smutty pictures who was embezzling funds of the organization. The man ends up hospitalized. The scene shifts back to Gloria's house. Gloria and Johnny are watching 16 mm films, projected onto a screen, and conversing. Gloria points that the increasingly unstable Dirk is both aroused and triggered to kill by viewing pornography. Johnny claims that he can still keep the killer under control. Meanwhile, Dirk has returned to the park. He is flirting with a woman and the two kiss. But then his lust turns to murderous rage. He strips off her clothes and then stabs her to death.
In the police station, Carson and Stone start discussing the fates of the women victimized by pornography. 'Mary Smiths' from 'Everywhere, USA' who graduate at the top of their class, were once great in a school play, and come into Hollywood seeking stardom.
The scene shifts to following the path of one 'Mary Smith' (Jeanne Willardson). The inexperienced actress is rejected by film studios and talent agents, before offered work by Johnny Ryde, who introduces himself as a director, without explaining the kind of films he directs. With childlike naivete, Mary agrees to work hard for him. She receives money for her expenses long before filming starts. She first becomes economically dependent on her employers, then she resigns into posing for revealing pictures.
The scene shifts from the fate of 'Mary Smith' to the exterior of Gloria's house, where Dirk is seen lurking. He breaks into the house and gets his hands into more smutty pictures. By this point, he is clearly addicted to both porn and killing. Later he returns to the park and finds another victim, a young woman who was feeding the ducks. This time the murder has repercussions for him. He leaves behind photos which he had touched with his bare hands. Through his fingerprints, the police discover the identity of the killer. The identity of the killer is leaked to the press, making the headline of the Hollywood Chronicle. Gloria's own overlords in "the Syndicate" then order her to remove Dirk permanently, as he is an unruly employee who is drawing negative attention for their organization.
Gloria and Johnny next argue over the best way to accomplish this. Johnny suggests an indirect way of killing Dirk, by sending on an errand in an old car with faulty brakes. In other words, arranging a fatal "accident" for him. As if aroused by the idea, the two partners then share a passionate embrace. Dirk survives his "accident" by leaping out of the car, then comes to Gloria's house seeking vengeance. He finds it empty and them manages to ambush an arriving Johnny. Johnny temporarily manages to convince his assailant that they could work together to topple Gloria off her leadership position. Dirk then murders Johnny, before being shot in the dark by Gloria, who assumed that she was shooting Johnny. The film ends with Gloria's disbelief that she shot the wrong man as the police arrest her.