From the moment that Jim and his best friend Charlie bug the staffroom and overhear two of their teachers speaking to each other in a secret language, they know there's an adventure on its way. But what does 'spudvetch' mean, and why do Mr Kidd's eyes flicker with fluorescent blue light when Charlie says it to him? Perhaps Kidd and Pearce are bank robbers talking in code. Perhaps they're spies. Perhaps they're aliens. Whatever it is, Jimbo and Charlie are determined to find out. There really is an adventure on its way. This is a nuclear-powered, one hundred-ton adventure with reclining seats and a buffet car. And as it gathers speed and begins to spin out of control, it can only end in one way ...with a Boom!