Bella's cat is a real witch's cat and Bella tells her everything! At school Bella's class are practising for a big gym display. Bella is rubbish at gym - hard as she tries, she can't manage to vault over the horse or climb the rope or walk along the narrow beam without falling off. But she knows Pegatha would be able to do it easy peasy. So they decide to cast a spell to swap places. Bella will be a cat and Pegatha will be a girl. It's a very short-lived spell, but it will last just long enough for everyone to think Bella is brilliant at gym - even if it's just for one lesson! The lesson goes really well - but then the spell lasts longer than expected . . .