The Subtle Knife - Philip Pullman

The Subtle Knife is the second book in the Dark Matter trilogy by Pullman. Like The Golden Compass, it's not really a kids book. It's too violent for one thing. For another, the novel introduces complex social and religious issues that most kids will struggle with. That aside, the story is compelling. I found myself staying up too late to finish, only to hit another cliff hanger at the end. Now I have to find the third book! Highly recommended.