Successful businessman David Bradshaw has created a nuclear shelter for his family. It's the ideal survival capsule. When the bombs drop, the family are safely cocooned underneath their country home. What David hasn't catered for is unforeseen circumstances, and the challenges of the family dynamic. He and wife Mary look on as their children, twentysomethings Tom and Holly, succumb to the stress of the situation by regressing into childish squabbling. For Holly, it is perhaps understandable, as she's missing the social life that has defined her recent years. She's in denial about the likely end of the world as she knows it. Her underlying health condition also makes it paramount that they find a habitable outside world as soon as possible. Tom, however, is in a worse position. The secret he carries makes this forced proximity almost unbearable. His anger and despair threaten to have all four inhabitants at each other's throats. And then the unexpected happens- Their futures will be more different than they could ever have imagined- if they can all make it out alive.
