Description
Anne Barron is a teacher's aide at a daycare center in Boston. One evening, she is relaxing on the playground carousel when someone pulls up on a motorcycle, wearing a black motorcycle helmet. She is startled as the stranger pulls out a kukri and starts spinning the carousel. The terrified Anne goes around until the kukri hits her. Lt. Judd Austin is the policeman assigned to the case. As he gets to the scene, he sees the girl decapitated with her head in a nearby bucket. The distraught director of the center tells Judd that Anne worked there during the day and was attending night classes at Wendall College.
At the hospital, Judd and his partner Taj discuss a similar case from the previous week, in which another girl was found decapitated with her head in a pond. They wonder if there's any connection between the two murders. At Wendell, the administrator Helene Griffin tells Judd that Anne was close to a girl named Kim Morrison. When asked if Anne had a boyfriend, Kim tells Judd that Anne was indeed involved with someone, but she doesn't know who. Judd enters Professor Millett's anthropology class to speak with him about Anne. The professor doesn't provide much information, but he introduces Judd to an exchange student named Eleanor Adjai. Eleanor leaves the school and goes to the local diner. There, she is creeped out by Gary, the busboy who appears to have mental issues. The waitress Carol asks Eleanor if she's in Millett's class and implies that he sleeps around, irritating Eleanor and she leaves. Gary follows her home. When she realizes this, she runs the rest of the way and quickly locks her door. She gets into the shower but someone tries to break in. Frightened, she gets out of the shower, only to find that it's Professor Millett, her boyfriend who had been locked out by accident.
Kim works at the local aquarium. About to leave work, she takes off her diving suit and is decapitated by the figure in a motorcycle helmet. A woman who was previously looking at the turtles screams after she sees Kim's head fall into the tank. Judd pays a visit to Professor Millett and is surprised to see Eleanor, who explains that she is his research assistant. Judd then informs Millett that a second student of his has been killed and asks him if he has had any affairs with his pupils. Annoyed by the question, Millett tells Judd to leave. Eleanor and Millett get into an argument and she goes to the diner to be alone. The professor follows her, and she tells him that she is three months pregnant. He's sympathetic, although he still manages to flirt with Carol. After the diner has closed, Carol is left to clean up. When the power goes out, she heads to the basement to investigate. The killer appears and attacks her. Carol escapes, but is then caught in an alley and killed. The next day, Carol's head is found in a water-filled sink and her body in a dumpster. Judd and Taj go to Gary' house since he is now considered a prime suspect, but Judd doesn't believe he was involved.
When Judd goes to Professor Millett's home again, he finds a collection of skulls taken from tribal headhunters from around the world. Eleanor doesn't see anything wrong with this. At Wendell, Helene tells Millett to stop sleeping around with his students and counsels student Kathy, who confesses that she too has been intimate with the professor. Helene invites the girl to spend the night at her house, resulting in the two sleeping together. Helene is killed when she gets up to answer the phone, and Kathy is killed shortly after discovering Helene's head in the toilet.
Judd is on his way to speak to Helene when he sees the killer fleeing. He chases the killer to Professor Millett's apartment. Inside, the killer is revealed to be Eleanor. She confesses the killings to her boyfriend and justifies the crimes by comparing them to tribal rituals he teaches in his courses. As the police are approaching, Millett puts on the helmet and flees on his motorcycle to divert the suspicion from Eleanor. During a chase with Judd and Taj, Millett is struck by a car and killed. Eleanor attends his burial and the police believe the case has been solved, although it is implied that Judd suspects Eleanor was the killer and Millett sacrificed his life to protect her. However, the case is closed and Eleanor moves back to England.