A well-wrought world, probably post-apocalyptic, in which Foon sets the story of a boy who sees his village slaughtered and his sister stolen by warrirors dressed as birds. The boy falls in with a brotherhood religious sect, while the sister is held as a marketing tool by the keeper's in the city--magicians who are augmented by technology. This SF-fantasy hybrid takes many twists and turns and has a unique magick not seen in any other fantasy series. The main dilemma between seeing what violence has done and needing violence to stop more destruction plays out nicely in the main character.
Oh, and probably the coolest new version of vampires I've encountered in a while.