Daniel Grayham, a man with paranoid schizophrenia, escapes from a mental asylum after killing a doctor and stealing his uniform. Three years later, a sociology teacher at St. Trinian's College is murdered whilst alone in a classroom, and a new teacher, Julie Parker, is hired by the school's wheelchair-using priest headmaster Father Janson to take her place the following semester.

During her first few weeks at St Trinian's, Julie befriends fellow teachers Cynthia and Mark, the latter of whom she develops a romantic relationship with. During this time, however, two female students of Julie's are killed by an unseen killer with a knife. Julie is told of one of the murders through a phone call from Cynthia, who later tells her that she is suspicious of Mark. Julie decides to investigate Mark's apartment room while he is out at the college, and finds both a pocket knife and various newspaper articles on murders occurring in the surrounding area, before Mark suddenly returns to the apartment, forcing Julie to flee.

The next day, Cynthia's mutilated corpse is found in a storage room within the college, causing it to be closed early for the day. Julie, deeply upset by the incident, tells Father Janson that she is quitting her job, then packs her bags as she prepares to leave town tomorrow. Before leaving, however, Julie, believing Mark to be the killer, calls Father Janson and asks him to meet with her at St Trinian's later that night. Mark suddenly appears, causing Julie to attack him and run before getting in her car and driving to the college.

After arriving and telling Father Janson of her suspicions, however, Janson reveals that he can walk, and also reveals that he is Daniel Grayham and has been the killer the whole time, his motives having been driven in-part by misogyny and religious zealotry. Julie runs away and tries to escape as Mark arrives, having followed Julie to St Trinian's. Before Mark can get inside the college building, however, Janson catches up to Julie and kills her by slicing open her back. Janson then calls the police in an attempt to frame Mark for the murder, but Mark notices a bloody knife sheath disguised as a crucifix on the wall of Janson's office. With his plans foiled, Janson is taken away to an insane asylum, where he is placed in a straightjacket.

• Forbes Riley (as Francine Forbes) as Julie Parker
• Ric Randig as Mark Hammond
• Dick Biel as Father Janson / Daniel Grayham
• Laura Gold as Cynthia Lockey

The original version of the movie was shot in 1981, and it clocked in at around 65 minutes. 13 minutes of additional scenes with students were filmed the next year to increase the running time.^[1]

The filmmakers were originally told they would have two weeks to shoot at Mercy College, but the school cut their time by a week, so many members of the crew wound up sleeping in the classrooms to ensure the film was finished. When students returned to school, they were alarmed to find crew members cleaning up fake blood.^[2]

AllMovie criticized the film for its "bone-headed plotting" and "half-hearted execution".^[3] In its review, Horror DNA said the film is "pretty forgettable except for a surprise twist ending that still holds up well today".^[4]

The website Really Awful Movies also found the film "very weak".^[5]

• Splatter University at IMDb