It's hard to defend the Earth from deadly monsters when you suspect you might be one of them. Discovering she's a walking magical weapon is just the beginning of Ada's problems. Her guardian thinks she's turned traitor, and her new boss has put her on goblin-catching duty. With enemies around every corner and a centaur uprising threatening to bring a bloodbath to Earth's doorstep, Ada and Kay are once again thrown into danger -- and a conspiracy...