It was 9.22, the moment when everything stopped. First there was the burning air, then came the darkness, the fire, and finally the frost.

Now, in a frozen, wasted London, a woman - uncertain even of her own name - is fighting to stay alive. Along with a small group of fellow survivors, she takes refuge in an abandoned skyscraper in what was once the financial centre. But spectres stalk the empty offices and endless corridors, and soon visions of a forgotten world emerge, a world of broken love and betrayal, and horrific, shocking mercies - a world more traumatic even than the desolate present.

Then is a novel of singular invention and bravery. With it, Julie Myerson has created an echo chamber of the heartbreaking and the terrifying, and an enduring apocalyptic vision.