At St Groan's Boarding School, all the smart children are mysteriously going missing. And since Linus's best friend Ang is a genius, he is clearly in danger.
What or who could be behind the disappearances? They soon discover (involving some risky eavesdropping) that Mrs Beardsley and the janitor, Leroy, are involved in a plan for world domination; a plan that involves getting rid of all the smart children of the world, starting with St Groan's.
But there's a third person involved in this plan too. Ang and Linus don't recognise the nasty, snurbly, smuffly voice, but when they manage to sneak a peak through a slot in the door . . . they're in for a very big shock!
St Groan's Boarding School is being invaded by space boogers!