While flipping through the atlas of Chang Ch'i-yun, one of China's most famous geographers, distinguished translator Bill Porter (Red Pine) developed a curiosity about the southwestern province of China. Dubbed Yun-nan, "South of the Clouds," this was the last area modern China to come under Chinese control. Originally conquered by the Mongols and eventually introduced to foreigners as a vibrant setting for trade, Yun-nan became a critical crossroad...