The movie that tells the story of two teenage sisters as Britain descends into an alien apocalypse. Told through the eyes of the younger sister, the sisters' descent into a post apocalyptic hell where they must choose between humanity and brutality in the fight for survival.

Cowen Rosewell lives with a small group of old friends in a scruffy flat in a small English town. Like many teens leaving school in 2014, there are few prospects or opportunities for people like Cowen and he has enrolled on a BTEC media course as a way of passing the time. His first assignment is to record everything in a week of his life. At first Cowen dismisses the random acts of violence he witnesses as the business as usual in a small English town. However, when one of his best friends is savagely attacked by a stranger, and in defending her they kill her assailant, the inexplicably serious nature of the dead assailant's injuries alert them to a more disturbing reality. As events escalate, Cowen and his friends discover that the town has come under a mysterious malign influence which is somehow controlling organised gangs who are rounding people up and taking them to a nearby factory. The friends hide, hoping to escape, but their sanctuary is discovered and over run. Finally ...