Artie Talbot, a spry and self-conscious trans boy descends upon Prom with his best friend Lucy. Artie's nominated for prom king, and is doing his best to hide his excitement. He doesn't believe his school would vote a transguy for Prom King despite Lucy's demand that he's already won. As they get closer to the court announcements, Lucy notices something on the back of Artie's pants. Blood. Artie realizes of all the nights, he's gotten his period on this one. This erupts into a metamorphosis that mirrors the emotional and physical transformation of the transmasculine experience and how it will change Artie’s life forever.