When Seung-do, a heart specialist, and his wife find their daughter So-mi showing strange symptoms by the day, they decide to attempt an exorcism ritual. Upon arrival, Priest Ban is sure there is the devil inside her, and the ritual seems to drive it out successfully, but ends in So-mi’s sudden death. As her funeral begins, Seung-do, who notices some strange signs in So-mi's body, confronts his conviction that she may not be dead yet, and her heart is still beating..