eOne Films

There's no proven formula for coming up with the "next big thing" when it comes to young adult franchises -- even Stephenie Meyer's only 1-for-2. But if there were one, it'd probably look a lot like "The Mortal Instruments," which combines werewolves, vampires, and other fantastical creatures with a "Twilight"-esque love triangle, elements of "Harry Potter," and a franchise-ready five novels (and counting). It's also got a sizable -- and vocal -- fan base, as director Harald Zwart learned when he agreed to take on the first adaptation in the would-be series, "The Mortal Instruments: City of Bones."

Franchise hopes or not, Zwart wanted to make sure "City of Bones" was capable of standing on its own, and not beholden to any theoretical sequels that might or might not materialize. That measured approach was rewarded back in May when a second movie, "City of Ashes," was announced months before the first was scheduled to hit theatres, with Zwart returning to the director's chair.

So, with "City of Bones" premiering this Wednesday, and "City of Ashes" going into production in September, Moviefone spoke with Zwart in advance of the release about what first intrigued him about the series, what he was most surprised to learn about the books' fan base, and why he's not a fan of the "young adult" label.

Moviefone: You, Lily Collins and Jamie Campbell-Bower were all signed on for the sequel, "City of Ashes," a few months before this one's August release. Do you take that as a major vote of confidence?
Harald Zwart: Yes. I think the producers are great for doing that. I think the fans were hoping that would be the case, and I think what we've seen so far from the response, it might be the right decision also.

Was returning for another movie an easy call for you? Are you looking forward to exploring this world more?
Yeah, I think I've learned to really love all these characters and the world. And working closely with ["Mortal Instruments" author] Cassandra Clare, it was also such a gratifying experience. She was so respectful of the whole filmmaking process. And I think the second book is just as exciting, if not even more exciting, than the first one.

What'd you see in the project that made you want to do this over other things you may have been offered after the success of the "Karate Kid" remake?
First of all, I thought the books are great. I think they have a great main character. They're rooted in reality, which is a rare case sometimes with these fantasy [movies], so the gateway into the fantasy is through a very relatable world. And I thought there was an endless source of great fantasy ideas. All those things combined, and the fact that I always wanted to do a "Harry Potter"-type movie with a female lead, [it] was just exactly what I was looking for.

How do you make a story with obviously fantastical elements like this feel grounded as well? Do you try to do more practical effects than CGI to balance that out?
All in all, the movie's effects will all obviously seem real, but the approach to doing them was very much an attempt to do as much as we could in-camera, so that the actors had physical objects to respond to or react to, and act with around them. But also just the approach on how to justify some of the fantasy that happens in the movie, we tried to somehow make that all seem grounded as well. There's a little bit of the "Da Vinci Code" approach to some of these fantasy ideas.

Who do you think that approach benefits more -- the audiences, or the actors themselves?
I think it's both. I think there is this unspoken little thing in the audience's mind that tells you things are real or they're not real. It helps the actors tremendously, but actors can usually get there if they have to. But I think the audience will appreciate that. We also shot it on film, which is more and more unusual these days, and also that gives the movie a certain texture.

What made you decide to go film as opposed to digital?
Just because I wanted this to feel like an old universe, as if this Shadowhunter universe had existed for hundreds of years. It echoes way back into the Middle Ages. And I felt like that classic look could be best achieved with film. I think great movies, such as the last "Harry Potter," as far as I know, and the last "Star Trek," they were all shot on film. And they do get a certain fairy tale texture to them that it's harder to do with digital.

Did you take any other lessons away from observing other successful young adult franchises like "Harry Potter?"
It's been an educational process. Just like when I did "The Karate Kid," I decided with the filmmakers and the producers that let's not use the term "kids' movie" or "family movie." Let's think of it as just "the movie." Same thing here. We tried not to categorize it as a "young adult [film]," because as soon as you start mentioning those kinds of terms, it dictates a certain way of looking at things. And we just wanted to make this a movie on its own terms.

I think what I did learn from following Cassandra to all her book signings, I've been very impressed with meeting the fans and seeing that they're actually quite mature, and they're older than I first thought. So the approach of just making this a really seriously good movie without kind of putting the target group in front of us was a good thing. Because I think we all underestimated how wide this target group is.

Were you surprised by the dedication of the fans?
Yes, I was positively surprised. I always get energized whenever I encounter them and see their enthusiasm and how devoted they are, and how well they know the universe. And how smart they are. And that they actually value things in the books that they can't find in other books. A lot of them are young people who've searched for something in other book series and didn't find it. And then when they started reading Cassandra's work, they identified with it.

When you're adapting somebody else's work like this, something that's so strongly identified with Cassandra by all these fans, how do you stay loyal to what she's done, but still put your own stamp on the movie?
In this case, I happened to read the script before the book, and normally when I read a script, I always read them with my own vision in mind. So I walked into this with a vision, and then I had meetings with Cassandra and I explained to her how I saw the movie, and she was very open. So I feel like it's been a really great collaborative process, where I've been able to make it mine and it still has been synchronized with how she's seen it in her head.

Do you think having her onboard with the film helps sort of legitimize this adaptation from her fans' perspective?
Yeah, I think so. I think, regardless, just getting her approval on some of these things, you know, she's been living with this universe a lot longer than I have. So sometimes it was just a very helpful shortcut for me to run things by her. And when she gets behind it, I think automatically the fans will understand that I've respected the book.

Lily Collins had said that she was fan of the books coming in. Did she ever give you any trouble about changing things or condensing things from the book?
No, Lily never gave me any trouble whatsoever. [Laughs] She's fantastic to work with, we had so much fun doing this. And I think she liked what I had to say about the character. I mean, first of all, the Clary portrayed by Lily is an older person than what she is normally in the book. That also has some consequences, so I think she liked the way I wanted to take the story. And Lily's not the kind of person who would give anybody any trouble. [Laughs]

"The Mortal Instruments: City of Bones" opens in theatres on August 21.

2013 Comic-Con: Harald Zwart Talks 'The Mortal Instruments: City of Bones'