West of Chang'an

In the tenth year of Tianbao, the Anxi Army had only two things left: their gleaming Mo Dao blades and the banner of the Great Tang.

When Duan Yunqi, a doctoral student from twelve hundred years in the future, fell into the ranks of this army, he carried with him an order that had never been delivered. He knew that ten days later, only three thousand of the twenty thousand Anxi soldiers would return from the Talas River. He knew that four years later, when war drums shook Yuyang, the Anxi Army would march to the emperor's aid and never return. He even knew that over the next forty years, the Tang banners would come down one city after another, west of Chang'an.

He knew when everyone would die. Himself included.

He had tried to change things. Every time he bent history, it took a page in return.

At last, he did something harder: he stayed. West lay Talas, and every ending he already knew. Behind him lay Chang'an, and home. Someone had left him a line on the whitewashed wall of an inn: Yunqi, go west. Don't look back.

This is the Anxi Army in the gaps between the pages of history: from ten days at Talas to forty years in Kucha, a man who knows how the story ends walks the last stretch of the Great Tang's journey through the Western Regions, until a lonely city stands ten thousand li away, filled with white-haired soldiers.