"Telepathically connected twins battle a totalitarian regime...Exciting, thought-provoking, and very hard to put down."--The New York Times Book ReviewMika lives in future London, behind The Wall: Solid concrete topped with high-voltage razor wire and guarded by a battalion of Ghengis Borgs, it was built to keep out the animals, because animals carry the plague. Or so Mika's been told. But ever since Ellie vanished a year ago, Mika's suspected his world may be built on secrets--and lies. When a mysterious organization starts recruiting mutant kids to compete in violent virtual reality games, Mika takes the chance to search for his twin sister--and the truth.