"The Merciless is chilling...think 'Mean Girls' meets 'The Exorcist.'"--MTV.com

"Pretty Little Liars fans, get a sneak peek at your new favorite book The Merciless...a nail biting thriller."--Seventeen Magazine

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.

By the shockingly twisted end, readers will be faced with the most haunting question of all: Is there evil in all of us?