Is there life after Harry Potter?

More than a year after J.K. Rowling unveiled her seventh and final Potter novel, Scholastic, its U.S. publisher, has all but fallen off the children's chapter-book bestseller lists. It has so far been unable to produce a series that can begin to fill the shoes of the boy wizard.

Now, Scholastic is hoping that the 39 Clues will provide them with a much-needed hit.

39 Clues pioneers a new approach to children's lit: More than just another set of chapter books, it is a multiplatform adventure series combining books with online gaming and card collecting. The 10-book series, which makes its debut today with The Maze of Bones, presents an interactive, immersive treasure hunt plotline; using the online component to create a community, kids can also compete for $100,000 in prizes.

The treasure-hunt theme of the 39 Clues series seems fitting.

Harry Potter shattered publishing records after it was first published in 1997 (sales now exceed 400 million copies worldwide), turning into an unprecedented success for Scholastic.

But a year after the final Potter book hit the shelves, Scholastic's shares have fallen off nearly 25 percent, as the children's publisher battles harsh economic conditions and a fruitless search to find a series that catches fire with the so-called "middle-grade" age group that Harry Potter targeted (roughly 8 to 12). Disney-Hyperion's Percy Jackson & The Olympians and Artemis Fowl, as well as Random House's Books of Ember, are three fantasy series that have sprouted up from other publishers to fill the Potter void.

With 39 Clues, Scholastic is banking on the idea that favorite pastimes like computer games and card collecting, paired with recent trends like social networking, will draw children in to the series.

"What we're trying to do is extend the reading experience," says Suzanne Murphy, the vice president and publisher of Scholastic's Trade Publishing Division.

"We know from experience that the idea of being a part of the story, being part of a community of kids, has big appeal."