The Mysterious Benedict Society by Trenton Lee Stewart

My AZ review: "I loved this book, not least the quirky outer cover, it doesn't even open like a normal book. The previous reviewer has given such an excellent account of the storyline that I wont add to that. Everyone keeps talking about Roald Dahl (who I adore), it is not like Dahl in feel, yes it's about kids and good and bad adults but the feel is completely different, more like Pullman in its level of sophistication, tight plotting and characterisation and its ability to address issues of childhood loss and the importance of memory. My only complaint is the end which screamed sequel, but otherwise an involving unputdownable read about four extraordinary but believable children."