In the small village Goksung in South Korea, police officer Jong-Goo investigates bizarre murders caused by a mysterious disease. His partner relays gossip that a Japanese stranger, who lives in a secluded house in the mountains, would be an evil spirit responsible for the illness. Jong-Goo decides to visit the stranger along with his partner and a young priest who speaks Japanese. They find an altar with a goat head, pictures on the walls of the infected people that died, and an attacking guard dog that prevents their departure until the stranger arrives.Jong-Goo finds one shoe of his beloved daughter, Hyo-jin, in the house of the stranger, and soon she becomes sick. His mother-in-law summons the shaman Il-gwang to save her granddaughter while a mysterious woman tells Jong-Goo that the stranger is responsible. Who might be the demon that is bringing sickness to Goksung?