Best friends Stanley and Manjit are part of Class 4B, which head teacher Mrs Bottomley-Blunt says is the worst class in the world. She says school is not about footling or fiddle-faddling or fun. It is about learning and it is high time 4B tried harder to excel at it. But they didn't mean to let the class stick insects loose in the wilds of the playground. And they really didn't mean to make a massive mess trying to do modern art (which may or may not have involved a mummified cat being stolen). These things just happened, even though they had plans to get away with it all.