The King of Pigs

Kyung-min leaves a message to Jong-suk at a crime scene. Jina delivers the message to Jong-suk. Thus, Jong-suk and Kyung-min reunite through the message for the first time in twenty years.

Jong-suk helps Jina solve the case. They found out that Kyung-min lived with an alias for a certain amount of time Meanwhile, Kyung-min determines revenge against An Jeong-hee who tormented him during his school days.

Kyung-min leaves a second message to Jong-suk at the murder scene. Jong-suk realizes that Kyung-min is revenging every perpetrator of school violence. And Jong-suk reminds a terrible memory from the past.

A special investigation team is launched and Jong-suk and JIna chase after Kyung-min. The team investigates the graduates of Shin-suk middle school. Jina meets the teacher and Jong-suk goes to Kang-min.

Jong-suk confesses that he also was one of the victims of school violence to Jina. And a video of Kang-min confined by Kyung-min arrives.

Jong-suk and Jina figure out the place where Kang-min is kidnapped. Kyung-min revives Kang-min's memory via quizzes. Kyung-min asks about Chul to Kang-min.

Jina got to know another key figure, Kim Chul. Jina asks Jong-suk about Chul, but he stays silent. So, Jina searches for the truth by herself.

Jong-suk figured out the next crime target and rushed to him. The third target sincerely apologizes to Jong-suk. Jina meets Chul's mother to investigate Chul.

Jina gets a step closer to the truth with the handwriting analysis of Chul's suicide note. Jong-suk reveals the identity of "Dog Park" as he looks for Kyung-min's next target.

Jina heads to the mansion to discover Chul's unperformed project. There she finds a note that Kyung-min left and confronts the truth from twenty years ago.

Jina detects the truth behind Chul's death. While Jong-suk's anxiety intensifies, Kyung-min comes into the police station.

Jong-suk and Jina doggedly track down Kyung-min. Jong-suk, Kyung-min, and other alumni from twenty years ago gather in one place.