In May, around midsummer, the heat gradually grew oppressive.
The great army of the Yin-Shang marched out from Xiqi, heading straight for the Five Passes.
From west to east, the Five Passes were the Sishui Pass, Jiepai Pass, Chuanyun Pass, Tongguan Pass, and Lintong Pass. They controlled the communication routes between Xiqi and the royal domain. Coupled with Zhenlong Ridge and Azure Dragon Pass—which stood astride the path between Xiqi and the Southern Capital—the Yin-Shang held the economic, political, and military lifelines connecting Xiqi to the outside world.
Chapter 997