Stranger — Season 1
An unlikely partnership is forged, between a passionate cop and an emotionless prosecutor, to bring an evasive serial killer to justice.
I Am Innocent
As a teen, prosecutor Hwang Si-mok received surgical treatment for his abnormally developed brain, but the procedure left behind serious side effects.
Just Turn On The Lights
The convict's strong plea for his innocence prompts Si-mok to review the CCTV clip. At the Yongsan police station, he runs into officer Han Yeo-jin.
A New Possible Suspect
Si-mok volunteers to appear on live national TV to discuss Kang Jin-seob. He also makes a bold promise to find the culprit within two months.
Kwon Min Ah
Rumors quickly spread about Si-mok's violent nature. Regardless, he persists in his investigation. He finds his mentee, Young Eun-su, suspicious.
The Second Huam-dong Case
Si-mok, puzzled by the details of the most recent murder case, visits the victim's home to seek more clues. Yeo-jin joins him in the investigation.
The Ringtone
New pieces of evidence only increase the list of possible suspects. In the midst of the confusion, a few begin to question Si-mok's innocence.
Ga Young's Phone
Si-mok and Yeo-jin team up to covertly pursue Seo Dong-jae. Just as Dong-jae is about to throw something into the Han River, Yeo-jin stops him.
Western Seoul Prosecutors' Office
Enraged by what the police did to Park Kyung-wan, Yeo-jin tries to confront her superior but is stopped by Si-mok, who warns her of the consequences.
Special Investigation
Si-mok selects key lawyers and police officers to be part of the special investigations team. Their probe begins with Dong-jae as the starting point.
Revelation
Fearing for Ga-young's safety, Yeo-jin proceeds to transfer her to a different hospital. A nurse informs Yeo-jin of something strange that happened.
Cold and Damp
The truth behind Ga-young's convulsions is revealed. Chang-jun's wife receives a travel ban. Woo-gyun asks Chang-jun to help him get out of his mess.
Disbandment
Si-mok and Yeo-jin discover perplexing leads while searching Kyung-wan's basement. Dong-jae goes back to Chang-jun's office to fetch his cell phone.
0 and 7
Returning home from the rooftop party, Si-mok discovers that an intruder has left something in his bedroom. Yeo-jin and Geon come over right away.
Another Body
Yeo-jin suspects a new killer is involved in the latest murder incident. Meanwhile, Si-mok collapses after leaving the autopsy.
Accomplice
Yeo-jin collects evidence as Si-mok interrogates the suspect. Many questions get answered, but the most important problem of all remains to be solved.
A Monster
Si-mok sets out to meet the one he believes is the real murderer. He gets his hands on a bag that will determine the futures of many people.