Fans of “The Mortal Instruments” can expect a new screen adaptation of their favorite book series. ABC Family has picked up the Cassandra Clare novels for a 13-episode season and has changed the title to “Shadowhunters,” according to the Hollywood Reporter. The novels follow center on Clary, a teenager who discovers a magical world when her mother goes missing. She realizes she is a shadowhunter, an angel-human hybrid who fights demons. Here are a few things you should know about the new series:

They have plenty of material -- “The Mortal Instruments” will be the starting point, as indicated by the promotional image above that the show posted on its official Twitter page. Yet the series can spin off or incorporate more than a dozen other novels. The “Shadowhunters” series is basically a series of series. Under the “Shadowhunters” umbrella there is “The Mortal Instruments” with six books, "The Infernal Devices” trilogy, "The Last Hours” trilogy and "The Dark Artifices” trilogy. Then there are the novellas, which include “The Bane Chronicles” and “Tales From the Shadowhunter Academy.” It seems Clare works a little faster than George R.R. Martin.

It was a movie -- If the premise sounds familiar, it’s because Lily Collins and Jamie Campbell Bower starred in the 2013 film, titled “The Mortal Instruments.” He played shadowhunter Jace. The film made just over $31 million, but that aparrently wasn’t enough to warrant a six-film franchise.

New casting -- Don’t expect Collins and Bower to reprise their roles. “Shadowhunters” will start from scratch. However, the TV series will utilize the same filming location as the movie version. Toronto will stand in for New York City once again. Production will begin in May.

Page-to-screen changes -- The series already is making some adjustments to small details. Clare confirmed on her Twitter that Clary will be two years older, making her 18. This might be a good change because the writers won’t have to incorporate some semblance of a normal high school schedule. Clary didn’t spend much time in class anyway, so it shouldn't affect the show too much.

Romance -- If you like tortured, supernatural romance, “Shadowhunters” is perfect. Jace and Clary are the major couple on “Shadowhunters,” but there will be plenty of other romantic storylines as well. Clare assured readers that the romance between the warlock Magnus and the shadowhunter Alec would remain in the TV adaptation.

Massive fandom -- If you haven’t heard of “The Mortal Instruments,” you’re late to the party. The series started in 2007 and with 35 million copies in print, the series has a pretty large following. Expect the show to fill up your Twitter feed when it premieres. Within minutes of the announcement, fans had the hashtag ShadowhuntersTV trending worldwide.

A premiere date for “Shadowhunters” has not been announced yet.

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