During the three years of Tianbao, the wind and sand swept through Longxi. Jiang Yihan reined in his horse at the Qilian Mountain pass, and his fingertips touched the water pattern carvings on the sword hilt. Camel bells were ringing in the distance, and a group of Tibetan cavalry was plundering a caravan. He remembered his father's last words: "The way of the sword is to stop the fight, not to stain the blood." But when the women and children wailed and pierced the sky, he finally rode out - the autumn water sword was unsheathed, like the moon breaking through the heavy clouds.