Gr 5-8-In this second book in the series, 13-year-old Nick Diamond refuses to be enlisted in Chief Inspector Snape's plan to make him the undercover cellmate of the notorious Johnny Powers in order to worm out the name of the Fence, the 15-year-old's partner in crime. But when Nick is mysteriously caught with a famous jewel in his pocket during a class field trip and he is arrested, tried, and sent to Strangeday Hall for young offenders with great expediency, it becomes clear to him that the Scotland Yard inspector wouldn't take no for an answer. Nick soon finds himself fleeing prison with Johnny and sneaking around London's underground to save himself (and his hapless brother, Tim). Horowitz has a knack for puns and humor, and he successfully combines it with a nonstop action mystery that has everything from hydraulically controlled buses to secret caverns. A readable and exciting adventure.-Lynn Evarts, Sauk Prairie High School, Prairie du Sac, WI Copyright 2004 Reed Business Information.