Tense thriller in which a couple's mournful retreat to a remote island is interrupted when an injured military man is washed ashore. Kate (Thandie Newton) has just suffered a miscarriage. Devastated by the loss, she and her husband, Martin (Cillian Murphy), head to the cottage on an uninhabited island they remember from happier times. Beyond the miscarriage, there are problems in the relationship and their attempt to resolve these issues isn't helped by the arrival of Jack (Jamie Bell). Apparently washed in by the tide, Jack claims that an airborne virus has been devastating the world and that the only way to survive it is for the three of them to stay inside the cottage. Trapped together in close confines, Kate and Martin try to make sense of Jack, his claims about the virus and their own relationship and will need to find answers before time runs out...