Mandy Lane (Amber Heard) is the popular outsider whom all the boys love and compete for her attention. She is invited to a pool party by Dylan (Adam Powell), and agrees to go under the conditon that Emmet (Michael Welch) is invited too. Emmet is Mandy's friend who is bullied by the popular group and is seen to be a freak. While at the pool party Emmet tells Dylan to jump off the roof of the house into the pool to impress Mandy. He does so but misses, hitting his head off the concrete killing him. Nine months later Emmet and Mandy have drifted apart, and Mandy has become friends with the popular group who invite her to a party at a ranch. She agrees to go. During the weekend away, the boys compete for Mandy's attention, while the girls are shown to be jealous of her. Despite the boys trying to impress her Mandy seems interested in the ranch hand Garth (Anson Mount). Members of the party begin to dissapear and in the morning only a few surviours remain. When trying to escape Garth is shot. Mandy stays with the injured Garth while the others go for help. Later, Chloe (Whitney Able) arrives back at the ranch, being chased by the killer who is revealed to be Emmet. However Mandy stabs Chloe, killing her, revealing Mandy is helping Emmet kill the group for bullying him for years. Emmet has become obsessed with Mandy, and when she decides she does not want to commit suicide he attacks her. The pair fight but Emmet is shot by Garth, allowing Mandy to stab Emmet to death. Mandy and Garth drive away, meaning Mandy has got away with the killings.