Bullets fly and bombs explode when John ""Trader"" Wooly fails for a new classmate--who turns out to be part of an international terrorist gang. A scavenger who is fascinated by Nazi artifacts, Trader finds life on an Army base near Munich agreeable, even though danger seems ever ready to reach out for him (see Trader Wooly and the Secret of the Lost Nazi Treasure); here, under an old abandoned mansion, he comes upon a secret cache of finely made toy trains and small, remote-control bombs--also toylike, but quite deadly. Then a mysterious young woman named Katrin attaches herself to him with a peculiar intensity; she is part of a terrorist plot to attack his school and, since he's seen too much, she also has orders to kill him. After several abortive but suspenseful attempts, Katrin fails--and is at last captured and recruited by US counterintelligence. The swiftly moving, moderately violent plot (all deaths offstage) will appeal to fans of action stories, but the characters are thin as paper: the women are mostly unlikable screamers and weepers, the terrorists crude and predictable. Nonetheless, though Trader is younger and nerdier than Raboo Rodgers' Cody Burke (Magnum Fault), the two share a love of machinery and a taste for derring-do--an old-fashioned combination but still one that creates exciting adventures.