In the woods outside the small affluent town of Cherry Falls, Virginia, a young teenage couple is getting romantic in a car when a female, black-haired killer appears and murders them both. Meanwhile, in town, teenager Jody Marken (Brittany Murphy) - the daughter of the local sheriff - is trying to deal with her boyfriend, Kenny (Gabriel Mann), who thinks it's time to go "all the way. " Jody gently tells him 'no', then goes back home only to find her father, Brent (Michael Biehn), upset that she's out past curfew. Brent and his deputies begin to investigate the murders the next day. They see that that the killer carved the word "virgin" into both victims.
At the high school, Brent runs into intelligent English teacher Mr. Marliston (Jay Mohr), who urges Brent to divulge more details of the murder to students and the town so as to eliminate the possibility of secrets. Soon enough, the female killer murders another teen - again targeting a virgin. Concerned for the town's safety, Brent holds a meeting at the high school to tell parents the nature of the crimes. (No students are invited, but Jody sneaks in. ) The female killer appears and strikes at Jody, but her father rescues her.
Word gets out in Cherry Falls about how virgins are being targeted. The school's worst fears are confirmed when a large-scale orgy is planned outside of city limits. At the police station, Jody describes the killer to an officer, who draws a composite sketch. Brent confides with an old friend (the current high school principal) that the suspect looks like "Lora Lee Sherman. " The two are both visibly nervous, and Jody listens in on their conversation. Later, Jody learns from her mother about the tale of Loralee Sherman. 25 years ago, Loralee was a high school loner.
She claimed that four popular boys at school - including Brent, and the high school principal - raped her one night. Her cries fell on deaf ears and she left the city for the rural outskirts, where she was rarely seen or heard from again. The night the student orgy begins, Brent is abducted by the killer and dragged away. Jody is riding her bike that night, as she has refused to have sex with Kenny at the party. She bikes by Marliston's house as he is dragging a heavy trunk inside. When Jody opens the trunk and sees her bloody father inside, she is knocked unconscious.
At the orgy, Kenny is there with a girl who he plans to have sex with, but after thinking, changes his mind and goes to find Jody. He drives to find her but strangely sees her bicycle outside of a house. Downstairs in that house, Marliston puts on a wig and makeup to "become" Loralee Sherman. Marliston reveals that he is Loralee Sherman's illegitimate son, then asks Brent to retell the story of what happened that night 25 years ago. Brent reveals that the four boys - including himself when he was very intoxicated - did indeed rape Loralee. Marliston says his mother became an abusive "psycho" after the rape and gave birth to a son (himself) fathered by one of the rapists.
With a close-up of both Brent and Marliston's (identical) eyes, it is strongly implied that Brent is in fact Marliston's biological father. By frightening virgins, Marliston anticipated a large high school orgy (which is happening at that very moment), which would thereby rob all the wealthy parents of their precious children's virginity (just like his mother lost her virginity under less than ideal circumstances). Kenny enters the house and frees Jody. Brent battles with Marliston, losing his life in the battle. Jody and Kenny flee to the orgy. Marliston follows and kills a deputy. He heads inside with an axe and mass panic erupts. After stabbing panicking students and then trying to escape, Marliston is pushed to his death by Jody.
The next day, Jody and her mother head away from the police station after submitting a distorted version of the truth..