In the aftermath of a devastating alien invasion, 19-year-old orphan Sarah Connolly (Dakota Blue Richards) tries to protect her blind brother (Jack McMullen) and her family's farm from the unseen alien race that is wiping out the Earth's population and destroying its natural resources. In her struggle to survive, Sarah faces further threat from the planet's desperate survivors including a mysterious wounded stranger (Karl Davies) who turns up at her isolated farmhouse seeking shelter, claiming his family were killed by bandits. But Sarah soon becomes increasingly sceptical of the wanderer's true identity and motives...