Kell travels between the Grey London of our world, the Red London of his, and the White London everyone fears -- as one of only two people with the ability to move between worlds, he is valued as a messenger. When his interest in tokens from other worlds results in mortal danger, he finds himself at the mercy of a Grey London thief, Lila Bard, who offers her help and her sarcasm. An inventive and truly magical book, Schwab invents a miraculous and detailed history that is easy to slip into and fully believe.