The double story line and rather challenging language make this a book I'd recommend for teenagers and adults rather than children. It's very much a coming of age novel, but there's much more to it than that.
The plot of the book is compelling and has all the ingredients of a page-turner: suspense, humour, red-herrings and unexpected revelations. Add to this the dual historical backgrounds and well developed characters and you have a book well worth reading. I thoroughly enjoyed it.
You can read excellent reviews of this book on amazon UK http://www.amazon.co.uk/ and USA http://www.amazon.com/ .