The Mortal Instruments: City Of Bones' prequel has been announced before the first film has even been released.
The action adventure movie, starring Lily Collins, is set to hit cinemas in August, but rather than waiting to see how it does, Constantin Films who own the rights are already planning a prequel, according to the Hollywood Reporter.
The film is based on the fantasy romance books by Cassandra Clare, aimed at teenagers.
They are set in Victorian England and follow a girl who finds out she is part of a hidden race of angels known as Shadowhunters locked in a battle with warlocks and vampires called Downworlders.
The prequel, based on a spin-off series by the same author, explores the ancestors of some of the characters.
Constantin Films are so confident that the films will get a cult following that they have already signed up Stephanie Sanditz to write the prequel screenplay.
The prequel will be called Infernal Devices and Constantin is now on the hunt for a director, too.
Mortal Instruments stars The Blind Side actress Lily, alongside Lena Headey and Jonathan Rhys Meyers.
It is set for release in the UK on August 23.