Stranger

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.

In a heated first session with prosecutors, Geon makes a pointed argument. At Hanjo, Lee Yeon-jae faces an oncoming family power struggle.

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.