Across the vast Gobi Desert, a band of cavalry raced through the night, their horses’ hooves wrapped in cloth to muffle the sound. They skirted the city and headed straight for a mountain pass. The guards there were lax, drinking and gambling. The cavalry struck without warning, and the guards were cut down before they could react. The pass fell, and the barbarian army poured through, capturing three cities in succession and advancing on the western frontier’s key stronghold: Yumen Pass.
The commander at Yumen Pass was an experienced veteran, but his forces were too few, and he struggled to hold the line. By the time the imperial reinforcements arrived, the pass had fallen. The veteran commander was dead, and only eight thousand of the thirty thousand defenders remained.
