On their first day as partners, detectives Kang Do-chang and Oh Ji-hyeok pick up a series of calls with perplexing connections to a closed murder case.

Words get out of Incheon Seobu Police Station revealing that Lee Eun Hye, the daughter of a murderer Lee Dae Chul, has been kidnapped, murdered, and buried by a man who claims to be the culprit. As th…

The execution of death-row convict Lee Dae Chul nears as well as the evaluation for Do Chang’s promotion. Knowing that Lee Dae Chul has an alibi at the time of the murder, Do Chang needs to decide whe…

A big body of corruption sweeps over Violent Crimes Unit Two with the higher-ups continuously pressuring them to turn a blind eye to Lee Dae Chul’s case. Meanwhile, Ji Hyuk saves Seo Gyeong from Jo Se…

While clues proving a corruptive body’s close relation to Lee Dae Chul’s case pile up, Do Chang figures out a work-around to carry out a secret investigation on Jo Seong Dae. On top of that, Ji Hyuk h…

Do Chang confesses to Eun Hye that he wants to save her father, Lee Dae Chul. Unfortunately, Eun Hye can’t trust Do Chang who literally handcuffed and arrested her father for a murder he didn’t commit…

Although Do Chang and Mr. So prepare for the retrial of Lee Dae Chul’s case, Do Chang still needs to persuade Dae Chul to follow his lead because he is reluctant to take part in it due to the possibil…

It was already difficult enough for Do Chang and others to get a retrial approved. However, feeling desperate during the trial, Dae Chul falsely admits to his killing of Detective Jang Jin Soo. Meanwh…

After losing at the retrial, Do Chang gets demoted. With Do Chang out of the picture, Violent Crimes Unit Two also feels pointless to even fight for a comeback. Meanwhile, Ji Hyuk meets Seo Gyeong and…

Do Chang gets reinstated and returns to Violent Crimes Unit Two after coming to an agreement with Superintendent Moon. The team then focuses on Park Gun Ho’s case and stumbles upon Jo Seong Dae’s bloo…

With the help of a little stunt pulled off by Jae Hong, Do Chang gets one step closer to proving Oh Jong Tae’s crime. Meanwhile, Ji Hyuk barges into Yoo Jeong Seok’s office, asking if he is closely ac…

While Ji Hyuk manages to survive the ambush by Oh Jong Tae, the prosecution adds more pressure to Do Chang and his colleagues, invalidating their efforts to bring Oh Jong Tae down. Do Chang however co…

Jin Seo Gyeong hosts a secret meeting with Yoo Jeong Seok and Kim Gi Tae at Gawol Church, demanding them the truth regarding a missing person named Jo Seong Gi. In the meantime, Do Chang and Ji Hyuk s…

Even after the arrest, Oh Jong Tae still has the audacity to claim his innocence and goes on to emphasize the incompetence and corruption of the police organization. Meanwhile, Seo Gyeong and Sang Mi …

Yoo Jeong Seok admits to his doings before his junior reporters and leaves the office, ordering them to stay put until his next instruction. While being threatened by Oh Jong Tae, Nam Guk Hyun offers …

The shocking death of Yoo Jeong Seok stirs up the public, and the case is now under a spotlight. As the prosecutor makes a confession to his previous wrongdoing out of conscience, Oh Jong Tae gets sen…

A serial killer is on the loose. As Do-chang battles past trauma, the investigation grows murkier, only taking him further from the truth.

Do-chang’s guilt grows after another unexpected death takes place. Others want to wrap up the case, but Do-chang and Ji-hyeok refuse to give up.

The detectives find some strong evidence and start going over CCTV footage. A man burns mysterious objects, and makes a suspicious approach.

Do-chang and Ji-hyeok are hot on the killer’s heels, but elsewhere another murder is underway. Cheon Sang-u keeps an eye on Cheon Na-na.

Do-chang finds out about the killer’s tragic past and realizes that one piece of his pattern of murders doesn’t line up. He induces a confession.

Na-na follows Sang-u and finds some evidence. The team is threatened with being broken up. The detectives investigate Jung Hui-ju’s acquaintances.

Kim Min-ji’s background is revealed. The detectives get proof that incriminates TJ Group executives. Ji-hyeok is curious about Na-na’s intentions.

Na-na’s press conference throws Woo Tae-ho into disarray. A suspect in the Hui-ju case is caught and some clarity is brought to the case.

The detectives question Na-na about the car accident. They investigate Tae-ho's previous whereabouts, but Choi Yong-geun is looking into this too.

Na-na preys on Sang-u’s weaknesses. A mysterious man follows Moon Bo-kyeong, while Yong-geun plans to use her connections to his advantage.

Yong-geun is arrested, but uses his experience to make the interrogation difficult. The detectives search for a motive for Sang-u’s murder.

Sang-u is furious after realizing that Na-na came close to turning him in. Ji-hyeok provokes Yong-geun in an attempt to make Sang-u culpable.

The detectives ask to reopen Tae-ho’s case and look for further evidence regarding his death. Na-na asks Ji-hyeok to make an allegiance with her.

The detectives question the gang who tried to kill Hui-ju’s grandfather. As they get closer to the truth, Na-na and Jang Ki-jin get into trouble.

Na-na passes evidence of her father threatening her to Ji-hyeok, but he uses it against her. Ki-jin files a false charge against Do-chang’s team.

While the detectives search for proof of Na-na’s crimes, she becomes chairman of TJ Group. Ji-hyeok gives testimony to get Sang-u released.