Shade's Children by Garth Nix

            Imagine a world where your fourteenth birthday is your last In a brutal city of the future, human, life is in the hands of the evil Overlords who have decreed that no child live a day past his fourteenth birthday. On that Sad Birthday, the child is the object of an obscene harvest--his brains and muscles are used to construct machine-like creatures whose sole purpose is to kill.

            Where only one thing can save them.

            The mysterious Shade--once a man, but now more like the machines he fights--recruits the few children lucky enough to escape. He gives them food, shelter, and the training they need to fight the Overlords. But Shade's sent many children out on missions--and fewer of them are coming back.

            And where even your protector may not be trusted

            By luck, cunning, and skill, four of Shade's children--Ella, Drum, Ninde, and Gold-Eye--have come closer than any to discovering the source of the Overlords' power--and the key to their downfall. But the closer the children get, the more ruthless Shade seems to become...