The Mortal Instruments: City of Bones isn't in theaters until this August, but Constantin Film is already moving forward on the prequel series Infernal Devices, which is a spin-off of Cassandra Clare's popular novel series.

Stephanie Sanditz, an actress with no real writing credits to her name, has already been hired to pen the screenplay for Infernal Devices. The Mortal Instruments is a fantasy romance that follows a young girl in contemporary times who discovers she is from a race of angels known as Shadowhunters, and that her kind has been locked in an age-old battle with a sect of vampires known as the Downworlders. This new story will trade back alley raves for Victorian England, and revolves around a new girl who goes on a journey of self-discovery.

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The book follows the ancestors of many characters from The Mortal Instruments: City of Bones, and because some of the characters are immortal, they also overlap. At this time, there are three novels in the Infernal Devices prequel series: Clockwork Angel, Clockwork Prince and Clockwork Princess.

Constantin Film is currently seeking a director. Stephanie Sanditz landed the writing gig based on her script for The Mediator, an adaptation of Meg Cabot's popular 'ghosts in love' romance novel series, which is currently being developed into a feature film with franchise potential.