Daniel knows that his mum was very ill once - mentally ill. She's fine now, and she's even landed a big new job as a head teacher. The problem is, she's head of his new school! It's so embarrassing - everyone is going to tease him.

But then things get even tougher for Daniel. With his father abroad, his mum stops taking the medication that prevents her illness coming back. As she starts behaving more and more weirdly, Daniel realizes that something is terribly wrong. And that he is the only person who can help her. . .

There are 176 pages in this book. This book was published 2008 by Pan Macmillan .

Gwyneth Rees has written under different names for many best-selling children's series, but Mermaids is her first work for Macmillan. When she's not writing, Gwyneth is a psychiatrist in a London hospital. She lives in west London with two cats.