Centered on the northeastern folk tradition of spirit mediums, this story blends shamanic legends, yin-yang and the five elements, and eerie folk tales to create a northeastern world where three realms intertwine: the human world, the spirit realm, and the underworld.
- The human world: The villages, forests, and towns of China's three northeastern provinces are home to ordinary people and spirit mediums, known as vessels for the immortals. Ordinary people both revere and rely on the spirits, while the mediums use their power to handle matters between the living and the dead.
- The spirit realm: Its chief clans are the Five Great Immortal Clans, known as Hu, Huang, Bai, Liu, and Hui: foxes, weasels, hedgehogs, snakes, and rats. Other beings include mountain spirits, tree monsters, and earth immortals. They have their own clan rules and hierarchy, from ordinary spirits to household guardians, altar spirits, and spirit kings. They must perform spirit-medium services and accumulate merit to advance their cultivation.
- The underworld: An overlapping “shadow world” inhabited by underworld officials, vengeful ghosts, and earthbound spirits. It is governed by the law of “yin-yang balance.” Mediums can communicate with the underworld through spirits, but excessive interference invites backlash.
