British horror written and directed by James Watkins. Infant teacher Jenny (Kelly Reilly) escapes for a romantic weekend camping by a woodland lake with her boyfriend Steve (Michael Fassbender), who - unbeknownst to her - is planning to propose to her. But the couple's peace is shattered when a menacing gang of kids encircles their campsite, steals their belongings and vandalises their car, leaving them completely stranded. When Steve confronts them, tempers flare and he suffers a shocking and violent attack. Jenny, who manages to flee the scene, becomes the subject of a brutal and relentless game of cat-and-mouse as she desperately tries to evade her young pursuers and find her way out of the woods.