In the early 1980s, a series of gruesome murders occurred at Crippen High School. A few years later, a film crew uses the now-abandoned Crippen High as the set for a film. But an uninvited guest makes an appearance on the set.
A few years ago, a mysterious serial-killer caused panic on Crippen High School. The killer was never caught. A movie company, Cosmic Pictures, has decided to make a feature movie about these events - on location, at the now abandoned school. Since members of cast and crew disappear without a trace, it seems as if history is repeating itself...—Mattias Thuresson
In 1982, at Crippen High School, a serial killer escapes justice following a murderous rampage. Five years later, Cosmic Pictures comes to town to make a film about the Crippen High murders in the abandoned school where they occurred. However, shortly after filming begins, police are called to the scene to investigate another massacre. Officers estimate seven or eight people have been killed, but cannot be sure because the murderer dismembered the corpses and scattered the body parts. Police Chief Deyner (Pepper Martin) interrogates the only survivor, Arthur Lyman (Richard Brestoff), who wrote the screenplay and was a student at the school at the time of the original murders. Lyman expresses his resentment of sleazy producer Harry Sleerik (Alex Rocco), who cut costs by deferring salaries and boarding the cast and crew at the school.
In a series of fractured, non-linear flashbacks, Arthur relates his knowledge of the murders to the chief. The first victim is Oliver (George Clooney), an actor who quit the production to star in a television show. As he leaves the school, Oliver is murdered by a man wearing a white theater mask, a black hooded robe, and yellow rubber gloves. Police officer and technical advisor Steven Blake (Brendan Hughes), a former Crippen student, replaces Oliver. He befriends lead actress, Callie Cassidy (Lori Lethin), and tells her that while he was a student, he dated a girl named Kathy Johnson, unaware that she was the daughter of the school principal. They fell in love, but she never returned after summer vacation. Amos (Al Fann), the school janitor, and Principal Kastleman (Andy Romano) also serve as technical advisers.
Two more crew members are murdered; an unnamed extra is killed, followed by Choo Choo (Panchito Gomez), a special effects assistant. Shortly after, cast member Richard Farley (Philip McKeon) is caught in a booby trap that drags his body into a steel-blade industrial fan.
While wandering the high school in-between scenes, Steve recounts to Callie his relationship with his high school girlfriend, Kathy; her father, Crippen's Principal Kastleman, is on-set serving as a technical advisor, but Steve has not seen Kathy in years. Meanwhile, Callie begins noticing that cast and crew are disappearing. Fearing the killer has returned, she and Steve begin their own private investigation. Callie's discomfort is compounded one day while watching the filming of a brutal scene in which the school biology teacher, Richard Birnbaum, is dissected.
When Steven inquires about Kathy's whereabouts, Kastleman claims she is in graduate school. After making love in one of the classrooms, Steven and Callie discover blood in the hallway and follow it to the men's restroom. Continuing their investigation, Steven and Callie find a number severed heads, including Harry and Josh's corpses, as well as a secret passageway to the basement, which contains a room filled with human skeletons.
They are confronted by Amos, the school janitor, who attacks Steve. During their fight, Steve inadvertently removes a latex mask from Amos's face, revealing him to actually be Principal Kastleman in disguise. Kastleman explains how years ago, Kathy discovered she was pregnant with Steve's child, after which Kastleman murdered her in a rage and hid her body in the school basement before killing multiple students. Callie and Steve manage to overpower Kastleman, impaling him with a javelin.
As Arthur finishes his story, Police Chief Deyner orders his men to the basement. Once they are gone, Lyman yells, "All clear." The many corpses on the lawn suddenly come to life, revealing that the recent murders were part of a stunt to generate publicity for the film. Harry Sleerik confesses that he did not think the plan would work until Callie and Steven discovered that Kastleman was the real killer. Meanwhile, in the basement, Kastleman springs to life and lunges at the officers before he is felled by gunfire. When police discover the bodies missing, they assume "some sicko" took them.
In the final scene, Arthur Lyman sits at his typewriter, and begins typing his latest screenplay Return to Horror High, which he intends as a sequel. It is revealed that Kastleman is Arthur's father. An unseen figure enters the room, dripping blood on the pages, and Arthur addresses him as "Dad."
