Jack is a very small and bendy boy. So small and bendy, that he can hide inside his own school bag! Other than bending and hiding, his favourite thing to do is to go to Old Mr Mudge's junkyard and ride the horses, Lightning and Boadicea. It's definitely better than going home to his drippy Aunt Violet, smelly Uncle Ted and evil cousin Kelly. But when he (accidentally) runs away, he finds himself on an adventure to free his mum from prison- with the help of a lot of talking animals!