We listened to this BBC Cover to Cover audio book over the holidays and it was brilliant. We're not alone thinking this as it won a golden Smarties award in 2000. William Nicholson is also known for writing the screenplay of Gladiators but this is his first attempt at a children's story.
It's essentially a fantasy adventure of three children on a quest. If successful, they will completely change the nature of the dreadful society in which their family despondently lives. Deeper than that, it's primarily an attack on conformism among children and the dangers of following a group (see interview by Jo-Anna Wildman). There is also a theme reinforcing the merit of a strong family.
Deeper still, it can be viewed as a satire of the absurdities created by a meritocracy and an examination of the idea of social inclusion. It's a book you can read at multiple levels.
Entertaining. Well paced. Superbly read by Samuel West. The audio book is six CD's long (7 hrs 45 minutes) and has no boring bits. Highly recommended. Or read the book yourself of course!
This is the first book in a trilogy and the other two books are available as well. Nevertheless, the climax brings the story to a satisfying close so you don't have to read all three.