In 1998, in a small village called Gyeyangjin, people started to get possessed and killed by a powerful evil spirit called Sohn. A young boy Yoon saw lost his parents because of his possessed older brother. A psychic boy Hwa Pyung was possessed and got his mother killed.
Gil Young finally catches Young Soo, but Hwa Pyung takes him to Yukgwang’s place as he is possessed. Yukgwang refuses to perform exorcism and calls Father Yang and Yoon. Meanwhile, Father Yang fails to drive away the evil spirits from Young Soo’s body and kills himself.
Hwa Pyung falls asleep and sees a fake taxi driver abduct and kill a woman and carry the dead body in his car. Hwa Pyung tells Gil Young to check if there are any missing person cases reported, and Gil Young finds one that matches what Hwa Pyung described. Meanwhile, Yoon visits the late Priest Han’s house.
Gil Young tries to find the culprit of the murder case after talking to Hwa Pyung, but keeps failing. Hwa Pyung visits the junkyard with Yukgwang, and tells Min Sang that his younger brother, Min Gu, is possessed. After convincing Min Sang, Hwa Pyung calls Yoon to perform exorcism on Min Gu.
Hwa Pyung and Yoon find out that they have seen each other in front of Yoon’s house 20 years ago. And Gil Young says that her mother was the female detective who was murdered by Yoon’s older brother 20 years ago. In the meantime, Yoon meets a woman who claims herself possessed. Gil Young senses that bloodstain found at a crime scene are related to Sohn.
Hwa Pyeong and Mateo stop the possessed woman, Kim Yoon Hee, from committing murder—at least that is what they think. But the police find the dead body of her boyfriend in a parking lot, and she becomes the prime suspect. Detective Kang comes back to the hospital to take Kim Yoon Hee, but she is gone already. The detective and the exorcist duo must find her and cast out the demon before she does something horrible.
The dead body of missing high school student from 20 years ago was found, and Gil Young starts investigating the case. Hwa Pyung insists that the congresswoman, Park Hong Joo, is possessed by Park Il Do while Gil Young thinks Hong Joo is the culprit of the murder case.
After meeting with Father Yang, Yoon finds out why Yun Hwa Pyung is obsessed with finding Park Il Do. Hwa Pyung is released from police custody and later is warned to stay away from Congresswoman Park by a thug. The next day, when Hwa Pyung visits his grandfather, an old lady comes to the house asking for help. Supposedly, her granddaughter is acting strangely just like he did when he got possessed 20 years ago.
The possessed girl Seo Yoon lures her mother into outside at late night and puts her in danger. Hwa Pyung, Yoon and Gil Young start to search them, but Yoon ends up being locked up in a basement with Seo Yoon. Yoon gets threatened by the evil spirits that possess Seo Yoon. In the meantime, Congresswoman Park Hong Joo goes to meet someone in the dark alone.
Yoon and Gil Young meet Hwa Pyung’s grandfather and get to hear the story of Park Il Do. Hwa Pyung finally finds his father, but his father yells at Hwa Pyung, saying that Hwa Pyung is Park Il Do. Yoon and Gil Young realize that Hwa Pyung’s father and grandfather have different memories of the past, and one of them is lying.
Hwa Pyung’s father, who had been missing for a long time, suddenly appears before Hwa Pyung. While looking for his dad, Hwa Pyung becomes a suspect of a murder case. Gil Young must find Hwa Pyung before the police get to him first.
Father Yang doubts that Hwa Pyung is Park Il Do while Hwa Pyung thinks Father Yang is Park Il Do. Yoon tries to prove Hwa Pyung’s real identity after talking to Father Yang while Hwa Pyung visits Father Yang to prove his real identity after tracing the phone number. Meanwhile, Bong Sang shows some strange symptoms after meeting someone at a hospital.
Detective Goh who is possessed attacks Gil Young with a knife, and Gil Young fights back alone. Hwa Pyung and Yoon try to save Gil Young and perform an exorcism to Detective Goh. During the exorcism, the spirit that possessed Detective Goh keeps reminding Yoon of the prophecy.
Yoon comes to know that Father Yang is Park Il Do after attending his mass. Gil Young happens to meet Sister Kim, who claims that she has every proof of Park Hong Joo’s wrongdoings. Meanwhile, Hwa Pyung tries to find where Yukgwang is since he is disappeared.
Father Yang abducts Hwa Pyung’s grandfather. In order to find a clue on Father Yang’s plan, Hwa Pyung, Yoon, and Gil Young go talk with the priest who knew Father Yang 20 years ago.
Hwa Pyung finally finds out who it was that was under Park Il Do’s possession. Hwa Pyung asks Park Il Do to come into his body so that he can take care of it by killing himself. Meanwhile, Yoon and Gil Young feel something dangerous about Hwa Pyung and head for him to save him.