Nursery school teacher Jenny (Kelly Reilly) and her boyfriend, Steve (Michael Fassbender), journey to a remote lake in the wooded English countryside. Hiking to the lakeside, they meet Adam, a young boy gathering insects. Relaxing beside the lake, the setting is disrupted by Juvenile delinquency teenagers and their dog, who have ridden their bicycles to a spot within a few metres of the young couple. After they sleep overnight in their tent, they find their food infested with insects and their car tire damaged by a bottle left behind by the teens.