The alternative-reality adventure world of The 39 Clues, the time-travel world of Infinity Ring, and the fantasy world of Spirit Animals will converge in Scholastic’s Worlds Collide, an integrated marketing campaign that aims to connect the authors and fans of these multiple-platform series. The initiative features virtual and physical components, including an online hub, a national group author tour, and the release of an e-book bundle packaging together the inaugural novels in each of the three middle-grade series.

Launching April 1, the Worlds Collide website will offer new content representing a mash-up of themes and storylines from each series, which have a combined 22 million copies in print in the U.S. alone and have been translated into 28 languages. The online games that tie into the three series have more than 2.5 million registered players, who hail from all 50 states and 191 countries.

The Worlds Collide online hub will also offer kids weekly rewards, including fan fiction story-starters, which enable kids to work with the editors of each series to create a mash-up story with characters from all three worlds. The site will include a “real-time message board,” a new feature that will let fans across the globe interact with one another. Visitors to the site can also access writing tips and play alongside the designers of a newly expanded Spirit Animals multi-player game.

Four middle-grade luminaries who wrote the inaugural books in each series will hit the road together on the Worlds Collide #1s Tour, which kicks off April 22 in Seattle. Participants are James Dashner (Infinity Ring #1: A Mutiny in Time), Gordon Korman (The 39 Clues Cahills vs. Vespers #1: The Medusa Plot), Brandon Mull (Spirit Animals #1: Wild Born), and Jude Watson (The 39 Clues Unstoppable #1: Nowhere to Run).

At tour events, the authors will stage dramatic readings of all three series, voicing each other’s characters, excerpts from which will be posted on the online hub. Rick Riordan, architect for The 39 Clues and author of its debut title, The Maze of Bones, will join the quartet for the tour’s grand finale event at the Water Street Bookstore in Exeter, N.H. on April 25.

Due April 21, the e-book celebrating the Worlds Collide initiative, dubbed a “Powerpack” by the publisher, includes the three series’ debut titles in one volume: The Maze of Bones, A Mutiny in Time, and Wild Born. This marks the first time the publisher has bundled three titles together in a single e-book.

David Levithan, Scholastic’s publisher and editorial director, hopes that the e-book will further cross-pollinate the multi-platform series’ fan bases. “We took such a great leap into the unknown when we pushed the button to launch The 39 Clues in 2008,” he said. “And now these three multi-platform series have become tentpoles for us. We’re finding that kids come in the door with one series and then discover the others. This e-book gives them access to all of the series’ first books in one place.”

Noting that a significant number of new readers and gamers visit the The 39 Clues, Infinity Ring, and Spirit Animals websites every day, Levithan said that the tour (involving what he calls “a dream team of authors”) and the online components of the Worlds Collide initiative is a prime way to connect authors and fans of all three series.

“We’re hoping to give kids the full experience, where they can interact with authors and with each other. With the Worlds Collide online hub, they can jump from property to property. One of the things that makes us proudest is that fans of these series clearly feel like they are a community. On message boards they are certainly letting us know their feelings about every single plot twist! This new initiative will let them get even more involved.”