I've been reading the 39 Clues series lately. In case you aren't acquainted with them, they are an action-packed adventures middle grade fiction series, ingeniously laced with history and geography. If your middle grade reader suddenly starts asking you questions about Mt. Everest, Shaolin Monks, cobra venom, or phosphorus, you'll know that he or she has joined Amy and Dan Cahill on the adventure of a lifetime to find the 39 clues.
Suffice it to say, my kids (even the teens) are eating the books up in gulps. Although it's been a little disrupting to have them arguing over who has first dibs on whichever book they are currently on (I always win because I'm the mom), from the standpoint of a writer, I find the lure of the 39 Clues intriguing. How do they captivate the reader? What enticement keeps us from putting them down? In short, why do we keep reading them?
I'd like to explore the idea of the book you can't put down more, but at this point, I'd like some feedback. As a reader, what is the difference between the books that you can walk away from and the books that you just can't put down? What is their magic?