Series about Potto and Hilda, who live in their magical question tree with the Bookworms and the Weatherberries. They are joined by their friends Claribelle and Archie. In this episode, Potto's new invention, the transmogrifier 3000, goes mysteriously wrong, causing Potto and Samson the Bookworm to switch bodies. The friends soon realise that they need to work together to switch back.