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...