Later this month, another young adult series makes the jump from the page to the big screen when Cassandra Clare’s ‘The Mortal Instruments: City of Bones’ hits theaters. Recently, casting for the second film has begun, but there’s still plenty of promoting to be done for the first one. That’s why the film’s stars Lily Collins and Jamie Campbell Bower, along with Clare, are currently touring the country to promote the movie and one stop that they made earlier this summer was in San Diego, where they unveiled the first clip for all the fans in attendance to see. Now, for those of you who could not make it to Comic-Con, that footage has finally been released on the internet.

Yahoo! Movies brings us the clip showing the extended version of the scene that sees Clary Fray’s mother, played by ‘Game of Thrones’ star Lena Headey, being abducted after putting up one hell of a fight. The young heroine is also introduced to her first demon, but luckily the mysterious Jace Wayland is there to lend a hand. In addition to the clip, the video also features a special introduction from Collins, Bower, and the crowd in Philadelphia during the stars’ appearance at Franklin Mills Mall for a special Q&A and autograph signing. You’re likely to see more from that day here on soon, but until then, check out the first clip from the film below, followed by the synopsis:

When fifteen-year-old Clary Fray heads out to the Pandemonium Club in New York City, she hardly expects to witness a murder—much less a murder committed by three teenagers covered with strange tattoos and brandishing bizarre weapons. Then the body disappears into thin air. It’s hard to call the police when the murderers are invisible to everyone else and when there is nothing—not even a smear of blood—to show that a boy has died. Or was he a boy?

This is Clary’s first meeting with the Shadowhunters, warriors dedicated to ridding the earth of demons. It’s also her first encounter with Jace, a Shadowhunter who looks a little like an angel and acts a lot like a jerk. Within twenty-four hours Clary is pulled into Jace’s world with a vengeance, when her mother disappears and Clary herself is attacked by a demon. But why would demons be interested in ordinary mundanes like Clary and her mother? And how did Clary suddenly get the Sight? The Shadowhunters would like to know…

I’ve heard of bad dogs before, but that one had to be the worst! What did you think of the first clip from ‘The Mortal Instruments: City of Bones’? Will you be lining up to check out the next potentially big young adult film franchise? Let us know in the comments.

Starring Lily Collins, Jamie Campbell Bower, Robert Sheehan, Jemima West, Kevin Zegers, Lena Headey, and Jonathan Rhys Meyers, ‘The Mortal Instruments: City of Bones’ is coming to theaters on August 21, 2013.