On a foggy night, two college students drown at the beach. While Si-mok investigates, Yeo-jin tracks down a man who was at the scene of the incident.

Police and prosecutors each prepare members for joint discussions on investigative authority. Dong-jae brings Woo Tae-ha some cases of interest.

Yeo-jin recruits Geon. Digging into a policeman's death ruled as suicide, Si-mok and Dong-jae find signs that point toward a different story.

At the prison to interrogate an inmate, Yeo-jin runs into Si-mok and Dong-jae. Choi Bit has Yeo-jin deliver a mysterious file to an assemblyman.

Si-mok is ordered to find out what Yeo-jin knows about Bit's file. Ahead of a vote on the fate of her seat, Yeon-jae sets up an important meeting.

When Si-mok hears who’s gone missing, he starts gathering clues by going through phone records. Yeo-jin begins her own investigation.

Leading police efforts to locate Dong-jae, Yeo-jin connects the case to that of the dead policeman. Si-mok pays Yeon-jae a visit.

A perplexing photo containing a disturbing message surfaces. The police consider the possibility of the culprit being one of their own.

Si-mok turns his attention to an unusual case involving the sudden death of a former prosecutor, and finds that nothing quite adds up.

A witness, who says he saw the kidnapping, steps forward to identify the perpetrator. His claims could mean serious trouble for the police.

Taken off the case, Si-mok and Yeo-jin return to their work on the police-prosecutor council. Tae-ha and Bit head to a sensitive meeting together.

Kang Won-chul weighs a dilemma, and fields questions from Si-mok about the deceased attorney. A young prosecutor has something to show Si-mok.

A suspect is arrested, but Dong-jae remains nowhere to be found. In the interrogation room, Si-mok and Yeo-jin try to draw out a confession.

While getting to the truth about the night of the attorney's death, Si-mok and Yeo-jin learn about the involvement of a mystery person.

Details of the cover-up become public, but Si-mok isn't finished asking questions. The police-prosecutor council is called off.