The Lovely Dark — K.A. Last

Three teenagers.
One witch.
Twelve souls.

Harvey Anderson always knew the universe was against him, but there's a lot of stuff he never expected to happen, like having a crush on the most popular girl at school, and then falling into a giant hole in the middle of nowhere with her. And if that wasn't enough, somehow they managed to release a soul-sucking, ancient witch as well. So yeah, there's that. You'd think it'd be pretty hard to beat, but knowing Harvey's luck, it's about to get a whole lot worse.