Examines the phenomenon of Sudden Unexpected Nocturnal Death Syndrome (SUNDS) among Hmong refugees in the United States. In Hmong tradition, the natural world is alive with spirits. Many Hmong feared that the protective ancestor spirits from their native Laos would not make the journey across the ocean to the U.S., but they thought that evil spirits would not follow them either. However, according to interviews with 118 Hmong men and women living in Stockton, California, the nightmare spirit, dab tsog, was not left behind. Moreover, its nocturnal visits caused sensations identical to the symptoms of SUNDS-related events. Further research revealed that the Hmong nightmare could cause cataclysmic psychological stress leading to sudden death. Increased incidences of nightmares correlated with interviewees’ experiences of stress during the relocation process. Many of the Hmong interviewed also perceived a direct relationship between failure to perform traditional Hmong rituals – a consequence of living in a modern society – and the nightmare attacks. Men customarily enact these rituals, and Hmong men die disproportionately of SUNDS. When dab tsog tormented sleepers in Laos, the Hmong could turn to shamans to appease the angry spirits; their radically different life in the U.S. offers no such avenue.