The only living Neanderthal is stolen from a top secret government lab. The spies must find him before the evil Uzhmanis do. Katrina Houseman arrives at MI High. She has been working on a top secret project: N80, a real life Neanderthal, and needs the spies' help. N80 has been broken out of his cage, and Katrina thinks that the Uzhmanis stole him. They plan to take N80 and clone him to create an army of fighting Neanderthals - a possibility that doesn't bear thinking about. The spies set to work to find N80. MI9 get intelligence - N80 has been sighted running along a busy street in London. Carrie and Oscar rush to retrieve him, while Rose goes to Katrina's lab to investigate further. The spies don't trust Katrina, and wonder whether she has something to do with N80's disappearance. Carrie and Oscar manage to bring N80 back to HQ, meaning he's safe for now. Carrie and N80 immediately strike a bond, as Carrie makes him laugh. She names him Andy. At the lab, Rose has discovered an isotope. Andy is being tracked, but by whom? Suddenly, Andy breaks out of HQ and makes a run for it. Yhe spies chase after him, but they're not the only ones in pursuit: the Uzhmanis are at St Hope's and they've come for Andy.