Baek Seorin, a 27-year-old shaman. She runs the traditional shrine 'Baegwoldang' on the outskirts of Seoul, where she sees ghosts, talks to spirits, and exorcises evil entities.

One rainy night, Guest, suffering from nightmares, visits Baegwoldang. Seorin discovers a mysterious entity following Guest and senses a special connection between them. From that day on, an old silver bell begins to ring on its own every midnight.