In this world, metal exists only as yao—spirits born from corrupted intent. Only those touched by evil thoughts, and newborns pure enough to sense all spirits, can see them. To children, the world glitters with fear; to adults, the danger is invisible. All weapons are made from wood, stone, or bamboo.

SengYi, a poor boy driven to robbery, becomes possessed by a yao as the price of survival. He thinks he can endure it—until he witnesses another yao kill his younger sister. From that moment, survival is no longer enough. Vengeance becomes his path.