Despondent and suicidal over the disappearance of his beloved Leven, Shaun goes from medical observation to the River Thames-where he wades into the freezing water intent upon ending it all. Instead, Shaun finds himself rescuing the mysterious floating body of a man in strange armour. And he learns that Leven is not dead, hope is not lost, love is not over. . .and the world of London is not the world he thought it was at all. Shaun and his sister Beth struggle to save the life of this man so like Leven as to be identical, although he has no memory of Shaun or anything that's happened to him. When their struggle becomes one of escaping their own tyrannical parents and violent past, it is Beth's wild, uncontrollable art that brings to them the clues Shaun needs to piece together where Leven has been, what happened to him there, who's coming for him now. . .and how only a fine thread of precognition hangs between London and oceanic apocalypse. Before it's too late, Shaun must recover this man's memory- The memory of water.