There’s something wrong with me. It’s hidden, under the skin where nobody can see, but I know. I know, my parents know, and my baby sister Anna knows. But that’s it. Not another soul. Not even my best friend. Because there are some things you just don’t talk about.

Misfit girl Josie Fletcher turns into a mermaid every night, and she hates it. So when she hears about the great city of Atlantis from a merman who washed up on her local beach she decides to go and visit. And blow it up if at all possible. Unfortunately for her, it turns out that someone else might just beat her to it. But joining forces with the bad guys is no big deal, right? Until she realises that being on the bad side has its disadvantages...