HarperCollins 02 October 2006 ISBN 978-0007210930 UK£5.99 PB
Amazon.co.uk Play.com
Philomel Books 03 July 2008 ISBN 978-0399247262 US$16.99 HC
Amazon.com
Puffin Books 02 April 2009 ISBN 978-0142413395 US$7.99 PB
Also available as a downloadable audiobook from