A lot of books are billed as, "The next Harry Potter." Are there any real "next Harry Potters"? No. At least, I don't think so. The book Tunnels has been long billed as that. This is Scholastic's attempt at the next HP. I guess, it's working, since two of the series are already on the bestseller list.
The idea of the series is total interactivity. You are part of the most powerful family of all time (my branch is related to Neil Armstrong!). You are on a quest for the 39 Clues, which lead you to the greatest secret of all time. To find the clues, you need to read the books, collect the cards, and play the online games. I already have 2 clues! Oh, and you're also competing for over $100,000 in prizes. Hooray!
The first book in the series is written by Rick Riordan, author of the Percy Jackson and the Olympians series (btw, the fifth book is called the Last Olympian!). Other guest writers will be in further books.
On the book itself, I really enjoyed it. Not as good as Percy Jackson, but the author's style really shone through. I woudn't recommend it fully on its wonderful writing, but for the awesome idea of the whole interactive aspect.