Molly Hartley (Haley Bennett), a 17-year-old girl, is stabbed with scissors in the chest one day after school in the bathroom by her deranged mother, Even though she survives and her wound is healed with only a scar left, she is still haunted in her dreams and hears things by the frightening experiance. Molly lives with her father since her mother is locked up in a mental ward outside the town she recently moved to. Her father enrolled Molly in a new school to help with the trauma and start a new life. However, as her 18th birthday approches, Molly must deal with both the stress of being a new student and with the continuing nightmares she has of her mother's attack. Joseph, a student at her new school, attempts to help her. However, Molly begins to evince symptoms of the same psychosis that took control of her mother's life, but eventually Molly discovers that her mother and others who share her mother's concerns want her killed in order to save her from a preordained life as a servant to the devil. It's revealed that Molly had died as the result of a miscarriage and her parents made a pact with the devil to save her life. But they would only have her till her 18th birthday, until she belonged to the devil. Joseph tells Molly that he is also to be a servant of the devil. He says Molly can either kill her father to break the pact, or turn over to the devil. She attempts to let her father live and not join the devil by stabbing herself and trying to kill herself. This attempt is in vain because the clock has already struck midnight.

The movie switches to a mental institution, where a doctor is talking to Molly. It is revealed that Molly's father has now been admitted to the institution, and Molly smiles and says she will not visit him. Molly becomes valedictorian of her high school, and dates Joseph. She is seen leaving her high school graduation with Joseph in a limousine, after being told by a servant of the devil (disguised as the school guidance counselor) that they'll "see her soon."

Thnx 4 reading!