Screen Gems, Constantin Film and Unique Features are developing a feature based on Cassandra Clare's bestselling THE MORTAL INSTRUMENTS series, reports ComingSoon.net. Jessica Postigo wrote the screenplay based on the series' first book CITY OF BONES.

The modern-set fantasy tale follows teen Clary Fray, whose family comes from a long line of Shadowhunters that hunt demons. After her mother disappears, she joins the Shadowhunters and enters of world of fairies, warlocks and werewolves to find her.

Constantin Film's Robert Kulzer, Michael Lynne and Robert Shaye are producing with Constantin's Martin Moszkowicz and Unique Features' Dylan Sellers exec producing. President Clint Culpepper and SVP production Eric Paquette are shepherding for Screen Gems.