Tanjiro tucked his sister into the cellar before dusk and locked the hatch. The city was too big. Demons moved through it like smoke, and he could not chase smoke. To kill the demon king one day, he first had to learn how to find the small ones. Tonight, he would stop waiting. He climbed the tall watchtower house he had claimed near the edge of the district. From the lookout, the streets spread out below him in rows of dim lanterns. He set his bright, color-streaked blade on the railing where the moon could catch it. Demons hungered for power. A weapon made to kill them would shine like meat in a window. He waited. An hour passed. Two. Then his nose caught it — the sour, wrong smell drifting up from a back alley. He marked the spot in his mind and slipped down the tower stairs. At the alley mouth, he drove a broken roof beam from a collapsed old house into the dirt. A marker. Proof a demon had passed here. He moved three streets over and caught the scent again. Another beam. Then another. By the fourth marker, the trail had a shape — a loop, a feeding route. He could see it now. A snarl split the dark behind him. A horned shape stepped from the shadows, yellow eyes locked on the gleaming blade at his hip. Tanjiro drew. He had wanted a way to track demons. Instead the demon had tracked him. The bait had worked too well, and now the fight had come early.