Jamie Campbell Bower, Lily Collins, THE MORTAL INSTRUMENTS: CITY OF BONESEverett

"The Mortal Instruments" took six years to adapt from a best-selling young adult fantasy to a teen-targeted film franchise, and no one was more invested in how the page-to-screen transformation would work than author Cassandra Clare. Clare spoke to Moviefone about the surreal process of having her supernatural universe turned into a film (now in theaters), and also shared everything from her favorite scenes to her thoughts on the gorgeous cast and her hopes for which fellow authors will have movies made based on their books.

Here are 10 things she wants moviegoers –- especially those already familiar with her books -– to know about the "The Mortal Instruments: City of Bones" adaptation.

1. Don't Expect a Carbon Copy of the Book
Every adaptation, Clare stresses, is just that; it's not a word-for-word retelling, nor could it ever be (at least without being five hours long). And although a small percentage of authors take a crack at writing a screenplay for their own book, Clare didn't. "I was more involved than some authors typically are," she tells Moviefone. "But I wasn't involved in writing the screenplay. I got to give notes. I gave like 50 pages of notes; some of which they took, some of which they didn't." But "even though they changed a lot from the books," Clare says "they did keep some really essential elements."

2. No, Alex Pettyfer Is Not Jace
Before "City of Bones" was cast, fans of the fantasy series lobbied online for the British actor Alex Pettyfer to play the beautiful, sarcastic Shadowhunter Jace. And even after the lead roles were filled, some TMI followers still weren't convinced. Clare says "All I could do was keep reiterating, 'I've seen their auditions, and in their auditions they embodied the characters beautifully, so hold off on judgment until you've seen the film.'" And yes, Pettyfer was a fan favorite, but Clare says that's because when the book came out in 2007 "Alex Pettyfer was a beautiful teenage boy," but when it was time to actually cast the role in 2012, "he looked like an adult, big and broad shouldered. He was no longer the way I described Jace as delicate, ethereal and beautiful. So those fans weren't really casting Alex Pettyfer; they were casting time-travel Alex Pettyfer, and without the TARDIS that could never be."

3. The Action Is Intense
"I'm really looking forward to fans seeing the action. I think they did a great job with all of the action sequences," Clare says. "The stunt coordinators and the director were committed to the idea that the Shadowhunters aren't superheroes. They get hurt; they bleed. They're stronger and faster than regular people, but they're not impervious." Because the actors did most of their own stunts, Clare says there's a "certain visceral feeling that's missing from a lot of action fims."

4. The Filmmakers Kept the Humor
Although there are a lot of demon vs. Shadowhunter action sequences in the movie, "City of Bones" will be happy to know that the directors also kept something Clare felt was integral to the characters: "I knew they needed to keep both Simon and Jace funny. They're both funny in different ways. Simon has great geeky humor, and Jace is really sarcastic." The guys' distinct brands of humor is clearly evident in the movie, like when Simon responds to hearing about the world of Shadowhunters with a hilarious "Ghostbusters" Gatekeeper/Keymaster reference. "You couldn't take the humor away from these guys or they'd stop being the characters they are," she says.

5. She's Pro Hot Asian Warlocks
One of the most memorable characters in the books is Magnus Bane, the High Warlock of Brooklyn. A sexy immortal, the character is Eurasian in the books, but for the role, the filmmakers originally wanted a white actor – something Clare wasn't cool with at all. "I think the admittedly default in casting is always white, so when they handed me the list of 'These are our seven top suggestions for who should play the parts,' the actors for Magnus were all white," she recalls. "That was the point at which I was like, 'No. Magnus is either Asian or I walk. I will walk off and you'll have to make the movie without my input. To their credit, they were like 'OK. If you feel strongly about this, and it's an important part of his character, we'll find an Asian guy.' So they only auditioned Asian actors for the part." As for Godfrey Gao, the model-turned-actor they eventually cast, she proclaims: "He's like the hottest man in the world; he's a supermodel; he's just gorgeous."

6. Certain Scenes Felt Like Dealbreakers
Like the meadow scene in "Twilight," or the cave kiss in "The Hunger Games," there are certain scenes from beloved books that just have to make the cut from page to screen, not only for story development but as a tribute to readers. "I really felt like they needed to keep Jace's story about his father giving him a falcon when he was a boy, because it tells an enormous amount about him." And of course there's the "swoony and romantic Greenhouse scene that captured the first time Jace and Clary realize they're falling in love with each other," and "the theme that 'all the stories' are true."

7. Seeing Her World Come to Life Was Surreal
Even though Clare had been involved enough to visit the set and see the production design and rough cut of the movie, nothing prepared her for seeing the finished film. "It was really cool to see it big and with a bunch of people," Clare says of the premiere. "I'd seen it before in small screening rooms, but it wasn't a movie experience. It didn't have the sound mixed or the score or the effects matted in perfectly. But having that real movie experience with an audience was an amazing experience. I got shivers watching it, because it was like 'Oh my God, that's my world coming to life!'"

8. The Sequel's Already in the Works
"City of Bones" is only the first in a six-part series (the final book comes out next year,) and Clare says the studio is "committed to doing 'City of Ashes,'" the second installment. "There's a cast attached already. Sigourney Weaver is the Inquisitor, and they're moving ahead with the production and storyboarding, and everyone's going off to train in a couple of weeks. So that one's going to happen." In addition to Weaver, British actress Lily Cole ("Snow White and the Huntsman") has reportedly been cast as the Seelie Queen, head of the manipulative faerie court.

9. The "Infernal Devices" Trilogy Is Waiting
After starting "The Mortal Instruments," Clare wrote a companion trilogy, "The Infernal Devices," that takes place in the same Shadowhunter universe, but in 19th Century England. The "City of Bones" producers have also optioned the period supernatural series, but that doesn't mean it's definitely getting made. "Ideally they'd love to make them all," Clare says, "but I think in terms of 'Infernal Devices' they're probably going to wait and see how 'Mortal Instruments' does, because they want to build off of it." For those curious about the other series, it starts with the book "Clockwork Angel" and follows 16-year-old American Tessa who travels to England to be with her older brother only to be pulled into a terrifying underworld of demons and eventually falling into an epic love triangle with Shadowhunter best friends Will and Jem.

10. There Are YA Adaptations She's Hoping For Too
Clare isn't just a best-selling author, she's also a big reader of the YA genre and would love to see many of her fellow writers' books turned into films. "I would love to see my friend Holly Black's 'Curse Workers' book series which is about a 'Sopranos'-like mob family that deals in magic instead of drugs. It's really great and would be a fun movie," she says. "There's a ton of them, like John Green's 'Looking for Alaska,' which would make a good 'Perks of Being a Wallflower'-like movie, but I know they're making 'The Fault in Our Stars,' so I'll be content with that. And Laini Taylor's 'Daughter of Smoke and Bone,' which is also about demons and angels is really good. I could go on and on."

EARLIER: ‚Äč'The Mortal Instruments: City of Bones' Family Review: 5 Things Every Parent Should Know About the Teen Fantasy

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The Mortal Instruments: City of Bones
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In New York City, a seemingly ordinary teenager named Clary Fray (Lily Collins) learns that she is descended... Read More