Once Chen Caozhi, Xie Daoyun, and their party of more than three hundred left Hefei, the weather changed. The clear, bright sky gave way to an endless drizzle that lasted all day. Seen through the curtain of rain, the clouds overhead were thick and dark; this rain did not look likely to stop in two or three days.
Horses were exceedingly scarce in Eastern Jin. Of the three hundred sturdy soldiers under Ran Sheng, all traveled on foot except the squad leaders, shizhang, tunzhang, and two scouts on horseback. They had prepared for a long journey and brought ample rain gear, but even with straw capes and bamboo hats, the muddy roads limited them to fifty or sixty li a day.
Shouchun lay about three hundred li from Hefei. The Huaiyang Mountains rose and fell in an unbroken chain, crisscrossed by waterways flowing into the Huai River. This region had belonged to Chu State during the Spring and Autumn and Warring States periods. A thousand years earlier, Sun Shuao, Chu State's chief minister, had opened channels from the Qisi River to irrigate the Yulou Plains here. Known to history as the Shao Reservoir, it was a vast irrigation project as renowned as Dujiangyan, shaped like melons strung along a long vine and capable of irrigating ten thousand qing of farmland. Chu State had grown powerful because of it. By now, however, repeated wars had left this once-prosperous granary desolate, with tall fortified walls appearing here and there across the flat fields and open country.
Fearing that displaced people from the Northern Lands would flood into Jiankang and threaten its rule, the Eastern Jin court had once forbidden clan commanders leading large numbers of refugees from crossing the river. Apart from a few refugee leaders such as Xi Chao's grandfather Xi