In a suburban neighborhood of Los Angeles, chaos brews when a headline blares: “MASS MURDERER OF 5 RUSS THORN ESCAPES.” Eighteen-year-old Trish Deveraux (Michele Michaels) begins her day unaware of the danger lurking around her. As her parents leave for the weekend, she disposes of a collection of dolls, a seemingly harmless task that is soon disrupted when a mysterious figure retrieves one from the trash.
At school, Trish's friends, including Neil (Joe Johnson) and Jeff (David Millbern), chatter about a slumber party planned for that night. The atmosphere shifts when a horrifying event occurs: a man abducts and brutally kills a telephone repairwoman, hinting at the presence of Russ Thorn (Michael Villella), an escaped convict renowned for his violent past.
During basketball practice, Trish plays alongside her teammates while the new girl, Valerie Bates (Robin Stille), is ignored by most. When Trish extends a friendly invitation to Valerie for the slumber party, she is met with rejection, a reflection of the social hierarchy at school. After practice, as the group discusses their party plans, the camera reveals Russ Thorn lurking ominously in a van, setting the stage for a night of terror.
As the evening unfolds, the girls gather at Trish’s house, festooned with laughter and carefree conversations. However, a sinister presence surrounds them. Mr. Contant (Ryan Kennedy), their neighbor, offers a false sense of security, blissfully unaware of the chaos about to unfold.
When a pizza delivery arrives, it’s an unexpected horror: the deliveryman is brutally murdered, leaving the girls in a state of panic. Unable to escape, they arm themselves with kitchen knives, preparing for confrontation. Each moment ticks away with suffocating tension as Jeff and Neil decide to split up to summon help, inadvertently sealing their fates.
Trish and her friends are thrust into a fight for survival as Russ Thorn picks them off one by one. The girls, engrossed in their own world, fail to perceive the lurking menace until it’s too late. With every horrific discovery—friends gone and screams echoing through the darkness—their hopes for a fun evening dissolve into sheer terror.
Efforts to escape lead to tragic encounters, with Diane's last moments captured in chilling silence and John's horrifying fate leaving the remaining girls paralyzed with fear. The struggle continues until only Valerie, Courtney (Jennifer Myers), Trish, and a few others are left to confront the monster that has targeted them.
In a climactic face-off, Valerie wields a machete with a fierce determination to protect her sister and friends. As the confrontation builds to a fever pitch by the poolside, the battle becomes a grotesque ballet of survival, where friendships are tested, and each choice could mean the difference between life and death.
In a final act of bravery, Valerie efficiently dispatches Russ Thorn, leaving the three survivors shaken but alive as the sirens of impending rescue wail in the distance. Their ordeal, punctuated by horror, has left indelible scars, transforming an ordinary night into a haunting nightmare.
