Imagine living in a 13-storey treehouse that includes a secret underground laboratory, self-making beds, a vegetable vaporiser and a marshmallow machine that shoots marshmallows into your mouth? Well Andy and Terry are lucky enough to live in one, where they have a series of completely mad adventures.And today Andy and Terry manage to get their dates all mixed up. They thought that they were going to rehearse their new play, The 13-Storey Treehouse, except they forgot to write it! And to make matters worse, they need to find flying cats, a mermaid, a sea monster, an invasion of monkeys, and a giant gorilla!Despite not having any of these things, they do have a box of costumes and props, some pretty awesome technology and friends to help out!