Just moments after the announcement that newcomer Godfrey Gao will be playing fan-favorite Magnus Bane in the anticipated adaptation The Mortal Instruments: City of Bones, author Cassandra Clare decided just one reveal simply was not enough. With casting moving steadily before filming begins in just one month's time, Clare announced two more characters that have been cast for The Mortal Instruments. This time however, the two stars joining the feature are high-profile and on two of television's most acclaimed drama series ever.

It was revealed that actress Lena Headey will be joining the feature in the role of Jocelyn Fray, the mother of main character Clary (Lilly Collins) who has been keeping quite a few secrets from her daughter, including the existence of an elite group of people called Nephilim a.k.a. Shadowhunters. Headey is best known for her strong mother roles on both Terminator: The Sarah Connor Chronicles playing title character Sarah Connor and HBO's hit series Game of Thrones as Queen Regent Cersei Lannister. Her outstanding performances as both are true examples of what make her the best and only choice for Jocelyn.

Meanwhile, Mad Men star Jared Harris has been cast as the eccentric character of Hodge who works at the Institute where the Shadowhunters work. Hodge is harboring a secret of his own, and like Headey the actor joins the production as really one of the only elder adults cast so far within the film.

Harris was nominated for his work as Lane Pryce in Mad Men this morning during the Emmy nods, and Harris has recently been seen on both Fringe and the successful sequel Sherlock Holmes: A Game of Shadows. Currently, Harris is wrapping up his role of Ulysses S. Grant in the Oscar-worthy biopic Lincoln directed by Steven Spielberg.

Filming on the first in what hopes to be a franchise of films kicks off in Toronto next month. The cast so far also includes Lily Collins, Jamie Campbell Bower, Robert Sheehan, Robert Maillet, Gao, and more with additional casting updates set to be revealed by Clare herself as the weeks continue. Currently, The Mortal Instruments: City of Bones is set for release on August 23rd 2013.

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