Marlene King is leaving her Liars for another twisted clique — but don’t worry, the move isn’t permanent.

The mastermind behind Pretty Little Liars is adapting Danielle Vega’s horror novel The Merciless into a feature film for Lionsgate (aka the same studio behind The Hunger Games). Marlene announced the exciting news on Tuesday, tweeting: “It's official-I'm teaming up with @lionsgatemovies @alloyent to write the feature #TheMerciless. I promise it'll scare the DEVIL out of you.” She’ll be writing and directing the feature film.

And she’s not kidding! The novel, which was inspired by real events, follows a new student in town as she gets to know the popular clique in high school. As we all know, sometimes the prettiest girls in town hide the ugliest secrets, but we’re dealing with something much more sinister than psycho stalkers and mean texts. Her new friends compel her into joining them in a dangerous exorcism of a punky, rebellious fellow classmate — and things take a turn for the worse.

Read the official synopsis for The Merciless below:

Brooklyn Stevens sits in a pool of her own blood, tied up and gagged. No one outside of these dank basement walls knows she’s here. No one can hear her scream.

Sofia Flores knows she shouldn’t have gotten involved. When she befriended Riley, Grace, and Alexis on her first day at school, she admired them, with their perfect hair and their good-girl ways. They said they wanted to save Brooklyn. They wanted to help her. Sofia didn’t realize they believed Brooklyn was possessed.

Now, Riley and the girls are performing an exorcism on Brooklyn — but their idea of an exorcism is closer to torture than salvation. All Sofia wants is to get out of this house. But there is no way out. Sofia can’t go against the other girls… unless she wants to be next...

The Merciless will hit bookshelves on June 12, 2014. We know Marlene has a penchant for horror, so we can’t wait to see how she tackles this new endeavor.

Crystal Bell is an editor at Wetpaint Entertainment and our resident fangirl and pop culture enthusiast. Follow her on Twitter and Google+!