Martin may have seen his sister, Cassie, to safety at the end of The Sky Inside, but his adventure is far from over. There's still a totalitarian regime in place, murderous game shows on the air, and a couple of government agents on Martin's tail. When Martin and his AllDog, Chip, go back to his old suburbs to check up on Mom, they get a lot more than they bargained for when they end up escaping with both parents. But the biggest surprise is yet to come—the heart of the government's central power is closer to Martin than he ever suspected.