Newly divorced medical doctor Sarah Cassidy (Elisabeth Shue) and her 17-year-old daughter Elissa (Jennifer Lawrence) move to a small, upscale suburb. They are disturbed to discover the house they are moving into is on the same street as a house in which a family used to live until the parents were murdered. The story of the massacre is told to them by the neighbors. Four years prior, a girl named Carrie-Anne Jacobson killed her parents, then fled into the forest and was never seen again, leaving her brother Ryan (Max Thieriot) as the sole survivor. Ryan now lives alone and is hated by his neighbors; Bill Weaver (Gil Bellows), a local police officer, appears to be Ryan's only supporter.