The movies are based on the fantasy novel series by Cassandra Clare, which follows a young woman named Clary Fray (Lily Collins), who learns that she comes from a long line of Shadowhunters, a group that tracks down and kills demons, vampires, faeries, and other mystical creatures. Sigourney Weaver is portraying the leader of the Shadowhunters, who is on a personal mission to find the man who killed her son. Lily Collins, Jamie Campbell Bower (Jace Wayland) and Aidan Turner (Luke Garroway) are expected to reprise their roles in the sequel, along with several other cast members from The Mortal Instruments: City of Bones.
The Mortal Instruments: City of Bones director Harald Zwart is returning to direct the sequel, working from an adapted screenplay by Jessica Postigo, based on Cassandra Clare's second novel in the series. Production is scheduled to begin in October. The Mortal Instruments: City of Bones opens in theaters nationwide August 21.