HarperCollins Children’s Books has bought Seven Wonders, a seven-book middle-grade adventure series by Peter Lerangis, author of three books in Scholastic’s bestselling The 39 Clues series. The first book, The Colossus Rises, goes on sale February 5, 2013, with six more novels to follow every nine months. Harper declined to discuss the financial terms.

“I call it Indiana Jones meets Percy Jackson,” says Lerangis’s editor, David Linker, of the series, which follows four tweens on a globe-spanning quest to unlock the secrets of an ancient world. “It was Peter’s idea and inspiration, and we helped him shape it. He’s got the whole thing mapped out – a very elaborate story arc for the books, and for the prequel novellas that will come out before each of the books.”

Those prequels are the Seven Wonders Journals; the first, The Select, will be released as a free e-novella on December 18. Subsequent journals will be released in both digital and print formats (at $2.99) seven weeks prior to each novel’s publication.

“They’re a deep dive into various characters throughout the series,” Linker says. “You get a behind-the-scenes look at the action that’s happening off the page.”

Plans call for a 15-city tour timed to the publication of The Colossus Rises, as well as what Linker says will be a “very robust Web site” that will launch in December with the first prequel. Each of the seven novels will be released simultaneously in hardcover and e-book, with paperback editions coming out eight months later. Book seven comes out in summer 2017, a prospect Linker says “blows my mind. I’ve worked on a lot of big projects before, but never anything of this size and complexity.”