In 1381, the Ming Dynasty dispatched a massive expeditionary force to the rugged frontier of Southwest China to pacify Yunnan. While the empire's borders eventually shifted, these military personnel and their families remained, taking root as the Tunpu people--a Han Chinese diaspora that has preserved its fourteenth-century traditions with remarkable resilience for over six hundred years. Dancing the Spirits provides a comprehensive ethnographic study of this community through its most vital cultural expression: dixi, or Ground Opera. Far from mere entertainment, this ritualistic masked performance serves as a localized spiritual practice, where village performers don hand-carved masks (lianzi) and reenact the martial epics of the Central Plains. This work chronicles the complex mechanics of cultural transmission, documenting the artisans and shentou (troupe leaders) who have guarded this "living fossil" of Chinese theater against the pressures of modernization. Tracking the art form from its suppression during periods of political upheaval to its introduction to the global stage at the 1986 Festival d'Automne in Paris, the narrative archives a living heritage that is simultaneously a military legacy and a distinct branch of folk art. Drawing on firsthand observation, interviews, and local research, Dancing the Spirits offers an essential resource for scholars of East Asian anthropology, performance studies, and regional Chinese history.