Maggie and Eleanor Crabtree love to annoy stuffy grownups with their quick wit and reckless behavior. But when the girls get kidnapped and imprisoned in their own family mansion on the rugged west coast of Scotland life becomes a lot less fun. This gang of international art thieves will make their lives miserable until their father, a famous art historian, gives the crooks a priceless collection of goblets, brooches and swords. Surrounded by evil, mean humans and a slobbering guard dog they have no way to escape... unless a scruffy, rude, bad-tempered rock creature can help them come up with a plan involving secret codes, frozen pizza, a tape recorder, stinking sausage meat, a rusty paint can and a chamber pot full of poop.