Measle's mum and dad have been kidnapped! It's up to Measle to save them...but that's a difficult thing to do when you've been left holding the baby, literally. Because Mum's last words to Measle were that he should look after Matilda, his little sister. Babies are bad enough at the best of times. But this one is special. She's a mallockee - a magical being with power unseen for over a thousand years. She just doesn't know it yet. And neither does Measle. The weaselly wrathmonks do though. And they will do anything to get their hands on her. Can Measle stop them, save Matilda and rescue his parents? Sometimes it's tough being ten!