Mortal Instruments Lily Collins Harald Zwart

With "Twilight" wrapping up this year, and "The Hunger Games" proving a giant hit, the hunt is on for the next big young adult movie franchise. And we suspect that of all the projects brewing, "The Mortal Instruments" has one of the best chances. The book series by Cassandra Clare has sold millions of copies across its four novels (plus two more in a spin-off series, "The Infernal Devices") to date, as many as any of its competitors. And since the movie version started development, the books' fervent fan-base has come out in force for any tidbit on the project.

And now, the film is finally set to happen, courtesy of Constantin Films ("Resident Evil"): it has a new director in "Karate Kid" helmer Harald Zwart, a locked-in star in Lily Collins, and even a release date, of August 23, 2013. With the film finally moving forward, we decided we'd take a look at the source material, to take a guess at what kind of actors we may see joining Collins in the finished film.

The plot begins with 16-year-old Clary (Collins) and her best friend Simon getting into a New York club. While there, Clary interrupts what looks like an odd-looking gang taking on an innocent boy, only to discover that the boy is actually a demon and the gang are a group of demon-hunting Shadowhunters, invisible to all but her. From then, she's drawn into an ancient war between the Shadowhunters, sworn to protect humanity, and the Downworlders -- vampires, werewolves, demons et al. -- discovers that she has powers she's never dreamed of, and soon realizes that the Shadowhunters' greatest enemy might come from within. And along the way, she'll have to choose between Simon, who's long been in love with her, and Jace, who's she's feeling increasingly drawn to.

Objectively speaking, "The Mortal Instruments: City Of Bones," which is the first book in the series (the one we've read) is not Shakespeare. The prose and dialogue are clunky, and it's highly derivative -- equal parts 'Buffy' and 'Harry Potter' with a sprinkling of Neil Gaiman. But it is kind of fun, and certainly has the potential to be a more enjoyable movie than any of the "Twilight" pictures, in that things actually happen in them. So who do we think might be in the cast? It's worth noting that as a Constantin Films production, this isn't going to be a bank-breaker: don't expect A-list names from top-to-bottom. We're talking TV veterans, possibly with a few better-known character actors involved. Below, you'll find our suggestions for who we think could end up involved, and feel free to weigh in with your own favorites in the comments section.