The story is set in Maomao Village in modern southwestern China, an isolated ancient village that preserves a complete complex of Ming and Qing dynasty architecture as well as remnants of shamanism. The village has a strange geographical feature known as the "boundary between yin and yang": an underground river in a cave on the back mountain connects to the River of the Underworld, and a bronze slip bearing records of the Maomaozi ritual is hidden in the ancestral hall's cellar. At midnight on the first and fifteenth of every lunar month, blood-red reflections appear in the village wells. That is when vengeful spirits are at their strongest.
