Midway through the reign of the Ch'ien-lung emperor, Hungli, in the most prosperous period of China's last imperial dynasty, mass hysteria broke out among the common people. It was feared that sorcerers were roaming the land, clipping off the ends of men's queues (the braids worn by royal decree), and chanting magical incantations over them in order to steal the souls of their owners. In a fascinating chronicle of this epidemic of fear and the...