The monograph approaches the Tu Phu, the Religion of the Four Palaces of the Viet via an ethnography of its practice of Hau Bong spirit possession ritual. It relies on fieldwork data collected mainly in the alluvial plains of northern Viet Nam from 1998-2000. It uses a combination of performance and ethnographic methods, focusing on the life histories and personal interviews of informants, which are vehicles for them to tell their life stories and to describe their motivations to become spirit mediums. The book provides an understanding of the mediums of a complex and increasingly important and popular religious system. For them the spirit possession rituals are vital, even life-saving, and beneficial work. Through Hau Bong rituals, practitioners construct Viet traditional culture and keep it alive in traditional and imaginative ways. This work serves as an important resource for students and researchers interested in understanding the Vietnamese popular religion and traditional culture.