The Mysterious Benedict Society and the Prisoner's Dilemma by Trenton Lee Stewart

In this book the Mysterious Benedict Society sets out on its own to foil Mr. Curtain's nefarious plots concerning the Whisperer. This book is on par with its predecessors: I think it's a very inventive idea and I know that I would have loved it as a little kid, but the prose plods too much to make the reading as enjoyable as it should be. Sticky is still whitewashed on the cover, as well.