I downloaded the sample of this to my kindle, in order to see if it would make a good Christmas present for my niece,I was enjoying so much that (despite being 30 years past it's upper age limit) I bought the book!
The book is engaging, and convincingly written, and it certainly won't patronise its young readers. It is nicely sprinkled with humour, a great book to read to children. (Parents or teachers won't be tempted to take a short-cut to the end!)
The illustrations (also by the author) are accomplished, and translate well on to kindle.
(My only gripe - why are some people so multi-talented?)