Piper Lowery, a public library clerk in charge of liaising with the local middle school, can tell right away there's something strange about the new girl in eighth grade. Avery Wallace won't touch any kind of technology, not even the computers at the library, and her mother comes to school with her every day, refusing to leave her side--not even when Avery uses the restroom.

And then there are the rumors, the whispers Piper hears from kids in the hallway and parents around town: Avery's mother is a witch. Her sister and father were killed by something supernatural. A strange virus killed them.

Seeing how isolated and lonely Avery is, Piper befriends her but quickly realizes it might just be the worst decision she's ever made. Because there's something dark inside Avery Wallace, and it's spreading . . .