When a young couple goes on a weekend getaway to a seemingly tranquil lakeside cabin, they soon begin to regret the choice of such an isolated area. Jenny (Kelly Reilly) and her boyfriend Steve(Michael Fassbender), who plans to propose over the weekend, have only just arrived when they run into a gang of violent teenagers who are intent on terrorizing the couple. Their car is disabled, their possessions are stolen, and soon they are truly stranded. When Steve is attacked, Kelly is left alone to try to find help. The woods appear appear to be an endless maze which she has to navigate for any hope of survival. Just when she finally finds gets to the town where she thinks she's safe she finds it's really only just begun.