Having suffered from anxiety attacks since she was eight years old, creating monsters has become a sort of therapy for Marion Jones. When she sculpts and paints, her fingers donāt tingle, the heaviness lifts from her chest, and she can actually breathe. So instead of grabbing pizza and milkshakes after school like most other kids in South Haven, Marion holes up in her room, working away on her monsters. And itās paid off because sheās just finished her first full-face mask: a gruesome sea monster sheās named Winston. However, Halloween arrives with a Super Blue Blood Moon, and its powers somehow manage to bring Winston to life. To make matters worse, Marionās crush, Tyler Dash, becomes the object of Winstonās possession as soon as he tries on the mask, turning him into a red-flannel and Converse high-top wearing Creature from Connecticut. Marion has no choice: she has to follow Tyler to the Halloween dance to try and stop him. Will she be able to figure out whatās happened to Tyler and stop the monster from wreaking further havoc on the school? Or has she created a real-life monster thatās here to stay?