In a steel-lined basement on a near-future Thursday morning, Conor and Julia are waiting for the world to end. Julia has spent her life plagued by visions of darkness, and today is the day when, according to one of her dreams, Britain will be wiped out by a nuclear strike.

No one but Conor has ever believed her. They have prepared to spend years underground together, waiting for the radiation to clear and dreaming of the world they will rebuild when they emerge. But as the moment of truth draws nearer doubts begin to creep into the airless room with them. Can they trust each other and themselves? Have they done all they can to stop the end of the world? And what will they do with the long years ahead of them if Julia’s prophecies fail, and everyone lives?