Ning Yi is a nameless commoner from Xiling with an unusual gluttonous physique. He depends on Pei Fan, who is weighed down by a blood feud. By chance he also rescues the only survivor of the household of Pei Min, a decorated northern general executed with his whole family on baseless charges, and the two live as brother and sister, struggling to get by. While three princes fight over the throne and treat ordinary people as pieces on a board, Ning Yi takes his sister into the imperial city of Tiandu, where staying alive means ceasing to be a pawn and becoming a player. A rare bone flute binds him to the mysterious girl Xu Qingyan, and Xu Zang, a sword immortal of Shu Mountain, teaches him the highest swordsmanship. Together they set him on the path to becoming a swordsman charged with saving the world.