Mortal Instruments author Cassandra Clare and The Spiderwick Chronicles author Holly Black have landed a book deal for a five-book middle grade fantasy series.

Scholastic will publish the first book, The Iron Trial, in 2014. Editorial director David Levithan negotiated the deal with literary agents Russell Galen (for Clare) and Barry Goldblatt (for Black).

Here’s more from the release: “In this exciting new series, twelve-year-old Callum Hunt has grown up knowing three rules by heart. Never trust a magician. Never pass a test a magician gives you. And never let a magician take you to the Magisterium. Callum is about to break all the rules. And when he does, his life will change in ways he can’t possibly imagine.”

Constantin Film, a Germany-based independent film production company, has already snapped up the movie rights to this series. Robert Kulzer, who is currently producing an adaptation of The Mortal Instruments, will also serve as a producer for this project.

This project marks the first professional collaboration between the two authors who have shared a personal friendship for many years.

As we previously reported, Clare inked a deal for a new YA series called The Dark Artifices with Margaret K. McElderry Books, an imprint of Simon & Schuster’s children’s division. In May, she will release book five in The Mortal Instruments series, City of Lost Souls.

Earlier this month, Black released the final book of The Curse Workers trilogy, Black Heart. Currently, she is also working on another YA vampire novel project entitled The Coldest Girl in Coldtown.