Stevie never meant for things to go this far. When she and Dee—defiant, bold, indestructible Dee—started all this, there was a purpose to their acts of vengeance: to put the bullies of Woepine High School back in their place. And three months ago, Stevie believed they deserved it. Once her best friend turned on her, the rest of the school followed. Stevie was alone and unprotected with a target on her back. Online, it was worse. It was Dee's idea to get them all back with a few clever pranks, signing each act Love, Heather—an homage to her favorite '80s revenge flick. Despite herself, Stevie can't help getting caught up in the payback, reveling in every minute of suffering. And for a while, it works: it seems the meek have inherited the school. But when anonymous students begin joining in, punishing perceived slights with increasingly violent ferocity, the line between villain and vigilante begins to blur. As friends turn on each other and the administration scrambles to regain control, it becomes clear: whatever Dee and Stevie started has gained a mind and teeth of its own. And when it finally swallows them whole, one will reemerge changed with a plan for one final, terrifying act of revenge.