Angel Islington is the only person who can tell Door who killed her family and help get Richard back to his old life. But how do they get to him? The Marquis suggests a visit to Earl's Court - but it has a worrying tendency to move around. Meanwhile, Croup and Vandemar alert Door to the fact that there is a traitor in her midst... but who?

With the sacred key in his possession, only one person stands in the way between the Angel and his ultimate ambition - Door. As the apocalyptic climax looms, everyone faces their own destinies.