Cassandra Clare's bestselling book series "The Mortal Instruments" is headed to the big screen.

Screen Gems will develop the urban fantasy series into a potential franchise, starting with the first installment "City of Bones," according to Variety. Constantin Film and Unique Features will team with Screen Gems for the project.

"City of Bones" centers on 15-year-old Clary Fray, a seemingly ordinary girl who discovers she is the descendant of a warrior clan called Shadowhunters. Her destiny is tied to the secret organization, which is dedicated to combating demons around the world.

Jessica Postigo is scripting the adaption, with Martin Moszkowicz and Dylan Sellers serving as executive producers. Robert Kulzer, Michael Lynne and Robert Shaye will produce.

"City of Bones" ranked No. 8 in children's books on the New York Times Best Seller list in 2007.

Should the book's adaption enjoy box office success, audiences can expect to see big screen treatments for the series' other installments, which include "City of Ashes," "City of Glass" and the upcoming "City of Fallen Angels."

Clare recently announced that there will be two additional books in the series, "City of Lost Souls" and "City of Heavenly Fire."