There's a war going on between good and evil, and only a special few have the power to defeat it. While the premise is certainly familiar to avid YA readers, a new trailer for "Mortal Instruments: City of Bones," which debuted Monday (April 1) on Apple, makes it all look so very cool.

Based on the best-selling novel by author Cassandra Clare, "Mortal Instruments" follows Clary Fray, a teenager who discovers when her mom disappears that she and her family are not as average as she thought. Clary (played by Lily Collins) is part of the Shadowhunters, a half-angel, half-human race with the charge to destroy the demons that walk about the Earth in various forms. It's a lot to wrap her head around, but lucky for Clary, some really hot Shadowhunters take her under their wing.

The trailer gives lots of screen time to Jace Wayland (played by Jamie Campbell Bower), the gorgeous Shadowhunter who serves as Clary's tour guide into this hidden world. He's pretty handy with his sword, as well.

"You have an incredible gift. We need you. I need you," he tells Clary, setting up the supernatural romance to come.

Check out the trailer to see Clary transform from average teen to total badass as she learns that she, alone, is the key to humanity's survival. Also co-starring Jonathan Rhys Meyers and Jared Harris, "The Mortal Instruments: City of Bones" hits theaters August 23.

Check out everything we've got on "The Mortal Instruments: City of Bones."