Orphaned when their spy parents were killed during an operation, Tom and Zilla are normally cooped up at boarding school. But when the only way to get at a target is by using a child, MI5 bring them in to help. Mission Alert tells the story of some of their adventures; the brother and sister spy duo must dig deep to survive! - See more at: http://www.bloomsbury.com/uk/mission-alert-viper-attack-9781472929600/#sthash.EabS8Sk2.dpuf
