Robble loves his life in the country, and is appalled by the idea of moving to Edinburgh. With no space and no sun to bask in, his pet tortoise, Herman, will be equally perturbed by the change. The new house and school look grim, and the class bullies are quick to pick on him. At first, the only consolation is the time he spends with Herman in the back yard. But when his teacher asks the class to write about their pets, Robbie's story about Herman, and recent reports of tortoise thefts, intrigue his classmates. With a few new friends, things are looking up. Then one afternoon, Herman goes missing. Perhaps he's been the victim of a tortoise gang - or is the culprit is closer to home?