When the downtrodden Noor rebel in the West, Wen, overhearing a plan to crush the Noor with powerful war machines, leaves the ghostly Bo, now a boy determined to transform himself into a living machine, and journeys into the war zone to warn the Noor--and her great love, Melik. It's been a year since the collapse of the slaughterhouse where Wen worked as her father's medical assistant. Now she works in the clinic at the weapons factory and sneaks away to nurse Bo, once the Ghost, now a boy determined to transform himself into a living machine. The Noor are waging a rebellion in the west, and Wen overhears plans to crush Melik's people with the powerful war machines created at the factory. Determined to warn them, she journeys into the warzone and she discovers that a year of brutality has changed Melik. How much is Wen willing to sacrifice to save him and his people?

Sequel to: Of metal and wishes.