Held prisoner by the Burner forces in Philadelphia, Jess and his friends struggle to stay alive in the face of threats from both sides ... but a stunning escape guarantees worse is coming. The Library now means to stop them by any means necessary, and they'll have to make dangerous allies and difficult choices to stay alive. They have only two choices: face the might of the Great Library head on, or be erased from life, and the history of the world, for ever.