'Shadowhunters' Boss Promises "Surprises" But Says Series Will Stay True to Books

"We still get from point A to point B," star Katherine McNamara says of the adaptation of the 'City of Bones' book, "but the way in which we do that is a little bit different."
ABC Family/John Medland

The fervent fans of the Mortal Instruments book series have been eagerly anticipating the upcoming debut of Freeform's TV adaptation, and the executive producers want to keep the fans on their side.

"We are absolutely starting from the beginning of the books and we stay unbelievably true to the spirit of the books," showrunner Ed Decter told reporters Saturday at the Television Critics Association winter press tour. "We love the books and that's what got us involved with the project to begin with."

Based on Cassandra Clare's best-selling young adult fantasy book series, Shadowhunters centers on Clary Fray, who finds out on her 18th birthday that she comes from a long line of Shadowhunters — human-angel hybrids who hunt down demons. When her mother Jocelyn is kidnapped, Clary is thrown into the world of demon hunting with mysterious Shadowhunter Jace and her best friend, Simon. Now living among faeries, warlocks, vampires and werewolves, Clary begins a journey of self-discovery as she learns more about her past and what her future may hold.

The Mortal Instruments was most recently adapted for the big screen in 2013, with plans to turn the series into a film franchise like The Hunger Games and the Divergent franchise. However, Screen Gems decided not to move forward with that plan after City of Bones grossed just $31 million domestically.

"We still have had a version of it out there so we wanted to have surprises both for the real hard-core fans," Decter continued, "and then we also want to introduce the viewers that have never been exposed to the world carefully and slowly to the world."

McG, who directed the pilot and serves as an executive producer, drew parallels to one of the most popular book-to-TV adaptations of all time: Game of Thrones. "You gotta know what is the spirit of the book, what is the spirit of the expectation and do what you can to digest that, define it and give it back to the hardcore book fan but also the uninitiated who wants to watch television and get involved," he said. "I can't say that I've read every Song of Fire and Ice piece of material but I'm a Game of Thrones fan like the next person. So you really have to find that balance and thread that needle."

The first book of the series, City of Bones, serves as the "skeleton" for the first season of the series, according to star Katherine McNamara. "We still sort of get from point A to point B but the way in which we do that is a little different and our very own interpretation," she said.

Season one is "generally book one but some of the things that we have in the story come from book six, but they are just solutions to things that we wanted to clarify in the story so we're not going one-to-one with the books because the cast, the amount of money we have, all these different things tell us where we can go with the story."

In addition to the core books, there are also several offshoots such as The Bane Chronicles that the writers room said they also often looked to as resources.

"What we try to do is if we need to solve a problem or tell a plot point, what we do is first look to the whole canon of Cassandra's literature and find a solution within her books that help us out with a plot point or a story point that we want to do," Decter said. "Even characters that might not have been in the book, we sort of combine some things from the books to make that character so that we're really using the Mortal Instruments all the time and also, her offshoot things like The Bane Chronicles."

For example, Decter said producers are saving Idris, the capital, for the second season "if we're so fortunate."

Decter promises that these slight variances in story "expands out the world" rather than diverging from the source material. "Some things that were told very close to the character of Clary in the [book] were told very close to her character and we would then expand it and show other things that were going on at exactly the same time as that character was experiencing that. So it expands out the world," Decter said.  

"It’s a very simple reason: You can't tell a saga from the point of view of just one person. You have to tell all the pieces of the saga and so all these great shows that we so admire like Game of Thrones and all that, you have many places to go with the story so that you can tell all the strands of the saga. Its actually a pretty complex world, Mortal Instruments, which makes it so rich and which is why we're so excited about it."

Between the original series and spinoffs, McG said there's plenty of material to cover in what the creative team no doubt hopes are many future seasons to come.  "There's more than you could ever accommodate," he said. "For me it was always figuring out what to edit, and what to put in."

Shadowhunters premieres Tuesday at 9 p.m. on Freeform.