Plot

A pastor and a detective, driven by their beliefs, pursue a missing person case, with the pastor seeking retribution after a divine revelation identifies the culprit who abducted his son.

Sung Min-chan is the head pastor of a small but cozy church, who finds out that his wife is cheating on him with her personal trainer. He additionally learns of the development of a newly established mega church in the same area as his own small one, and hopes to be selected by the bishop to lead it, as a reward for his efforts in the recruitment of new members. However, the bishop's own son was the favored selection due to nepotism. One day, a pedophile on parole named Yang-rae comes to Min-chan's church and has his eyes on a young girl, a member of the church. Min-chan grows suspicious of him after accidentally seeing his ankle monitor. After the church session, his wife frantically calls him to say that their son has gone missing. Min-chan researches Yang-rae and learns that his criminal history involves kidnapping and physical abuse, which causes him to panic that Yang-rae might have kidnapped his son.

Min-chan stakes out Yang-rae's residence and discovers that he is preparing digging tools to bury someone or something. Min-chan follows Yang-rae's van to a secluded forest area and confronts him, only to discover that the van is empty, with his son nowhere to be found. Thinking he has misjudged Yang-rae, he walks back to his car only to inadvertently see that Yang-rae has disposed of his ankle monitor, leading Yang-rae to attack him. In the struggle, Min-chan accidentally pushes Yang-rae off a hill, and Yang-rae tumbles down and strikes his head on a boulder. His wife calls him and reveals that his son is safe and had been invited to a friend's house the entire time. Shocked that he has harmed an innocent man, Min-chan prepares to call the police and surrender himself, but he sees the likeness of Jesus Christ appear in a flash of lightning. Now convinced that God has given him the divine task to punish sinners like Yang-rae, he pushes Yang-rae's comatose body off a cliff to kill him. Meanwhile, Lee Yeon-hee, a homicide detective whose sister was raped by Yang-rae and had committed suicide thereafter when Yang-rae failed to receive sufficient punishment by the court, is tasked to find the young girl from the church, who has just gone missing and is suspected to have been kidnapped by Yang-rae.

The Bishop learns about his son's affair, and ashamed that his son has committed a grave sin in the Ten Commandments, decides to pass over his promotion to Min-chan instead. Min-chan, believing that his good fortune is a reward from God for his actions, confronts his wife, and she confesses to her affair. After that, he and his wife drive to a nursing home in the countryside for a religious event. In the nursing home, Min-chan is shocked that Yang-rae had not only survived the fall, but had crawled to the nursing home and had been receiving medical treatment. Convincing himself that God gave Yang-rae a chance to live for punishment, Min-chan sneaks Yang-rae out of the nursing home and tortures him. Yang-rae claims that he has indeed kidnapped the young girl, but refuses to divulge her location to Min-chan to hold it as leverage. Min-chan, in turn, does not believe Yang-rae. Yeon-hee investigates Min-chan and happens upon the place where Yang-rae is imprisoned, but she is knocked out by Min-chan. Min-chan intends to kill Yang-rae as a sacrifice to God, whilst framing Yeon-hee as the assailant. Yeon-hee urges him not to do this since Yang-rae is the only one who knows where the kidnapped girl is, but Min-chan is completely convinced that Yang-rae is lying and that the young girl is already dead. Yeon-hee breaks free and fights Min-chan. Yang-rae tries to escape but falls to his death from the building, but not before giving the clue of the kidnapped child's whereabouts to Yeon-hee. Min-chan is arrested by the police, and during interrogation, he justifies his actions as the divine will of God. It is also revealed that Min-chan likely suffers from pareidolia and apophenia, resulting in him believing that random occurrences and coincidences are the work of God and seeing images where there are none.

Eventually, Yeon-hee figures out Yang-rae's clue and deciphers that the kidnapped young girl is imprisoned in Yang-rae's old home, rescuing her just before the old home was to be demolished. In prison, Yeon-hee informs Min-chan that he was wrong about the death of the girl, but he refuses to believe her. Returning to his cell, he cleans a dark spot on the concrete wall with a wet towel and becomes emotional upon seeing what he believes to be the portrait of Jesus Christ imprinted underneath