 Tessa Hurst, a young teenaged girl who attends an English girls school, is raped in the woods in the vicinity of the school. The attack leaves her in a catatonic state after her traumatic experience. One month later, Susan Miller, another girl from the same school is attacked and is killed in the process. Julie West, the school s art teacher, witnesses the killer as he is leaving and in her hysterical state, mistakes him for the devil. She then decides to use herself as bait to catch the rapist. She is aided in her plan by Dr. Greg Lomax, who also happens to be treating Tessa. During the investigation, the police come up with a list of several suspects from the voyeuristic husband of the school s headmistress to Dr. Lomax. They eventually come up with a plan to try and catch the killer by administering sodium pentithol to Tessa to bring her out of her state. Just as Tessa is about to be injected, Julie realizes that the killer is a colleague of Greg s and struggles with him. During the struggle, Tessa wanders out of the doctor s office and returns to the place where she was raped. She is then confronted by her attacker, who again tries to rape and murder her.