Little Creeping Things
YA Psychological Thriller, Sourcebooks Fire (2020)
When she was a child, Cassidy Pratt accidentally started a fire that killed her neighbor. She's pretty sure she didn't mean to do it, and she'd give anything to forget that awful day. But her town's bullies, particularly the cruel and beautiful Melody Davenport, have never let her live it down. In Melody's eyes, Cassidy is a murderer and always will be.
Then Melody goes missing, and Cassidy thinks she may have information about what happened. She knows she should go to the cops, but she recently joked about how much she'd like to get rid of Melody. She even planned the perfect way to do it. And then she gets a chilling text from an unknown number: I'm so glad we're in this together.
Now it's up to Cassidy to figure out what's really going on before the truth behind Melody's disappearance sets the whole town ablaze.