1962, London during the Cuban Missile Crisis. What would you do if there was a real possibility that the world might end? Ray, aware of his parents' building worry, decides to take matters into his own hands. He builds a shelter in the woods behind his house in the hope that he never has to use it. Only to discover that someone else needs it more than he does. An American girl, reported missing, has turned up there. Why is she hiding? And with neighbour turning against neighbour, will Ray be willing to help her?