A young girl who belongs to Father Kim's parish becomes comatose after a hit-and-run accident. Father Kim finds out she is demonic possession. Father Kim along with a rebellious young seminarian named Choi who is unsure about spiritual warfare, try to exorcise the demon and confine it in a piglet. Members of rosicrucianism inform Father Kim that two of their priests were killed by this demon. During the exorcism, the demon manifests, inflicting unnatural bodily rashes. Choi initially runs out halfway through the exorcism attempt, but eventually decides to return, determined to finish what they started. Father Kim tells him to believe this ministry isn't in vain and the reward is in the Lord’s hand (Isaiah 49:4). Choi replies by quoting Ezekiel 2:6, and affirms he is prepared now. When they try to free the girl from the demon's powerful hold, they realize that the demon they are facing is an ancient one named Malphas and is far more dangerous than they ever thought. However, they manage to confine it in the piglet, but the police arrive and try to arrest them for killing Young-shin, acting on a complaint by her extremely traumatized parents. Choi runs out with the pig, faces many obstructions but successfully drowns it in the river as instructed by Kim (Luke 8:33). Young-shin who was considered dead shows signs of life, and Father Kim's and Brother (Christian) Choi's rashes disappear.