In small-town Wisconsin, Mayma is one of many to be inflicted with a life-altering change. At only six years old, she is turned into a Dullahan, an immortal headless horseman. On the night she is to be rescued from being tortured, the government strips her and all others like her of the right to be human. Her only salvation, Officer Amber Walkin, who against the eyes of the law takes in Mayma to raise as her own daughter. Her only goal is to give Mayma the best, most normal childhood she can all while seemingly the rest of the world would see Mayma as nothing more than a hunted trophy.
Along the way, Mayma will, against Walkin's desire, be witness and befriend those fighting for what they believe to be just. As opposing views are thrown about, the line becomes thinner on who to side with.