Dokgo Young visits Choi Ja Hye to complain about what she said on her TV show. Choi Ja Hye has an opening party for her law firm. Kim Hak Bum is upset that only he didn’t get an invitation to the party. While Hak Bum, Joon Hee, and Tae Suk are having a party, Yum Mi Jung and Kang In Ho meet each other in secret.

Hak Bum, Joon Hee, Tae Suk, and In Ho gather together for dinner. Mi Jung suddenly visits them. In Ho gets angry as Mi Jung teases him in front of Na Ra. Young continues his attempts to meet Mi Jung, but he hears that she has not been seen for days. Meanwhile, her dead body is found in the middle of nowhere.

Young arrests In Ho as a suspect on the case of Mi Jung’s murder. He thinks In Ho is the murderer and investigates the case to look for evidence that points to him. Na Ra seeks for Ja Hye’s help after seeing In Ho get arrested, and Ja Hye tries to reveal the truth behind the case as In Ho’s attorney.

Ja Hye and Young continue their investigation. However, Ja Hye finds more evidence that proves In Ho’s innocence and starts to think that one of In Ho’s friends may be the real culprit. As Ja Hye continues her investigation, Tae Suk, Joon Hee, and Hak Bum all get nervous.

As Yum Mi Jung’s corpse is returned to Tae Suk, Hak Bum, and Joon Hee, they become suspicious about each other. Na Ra finds a picture of In Ho and his friends, and she realizes that they have known Mi Jung for a long time. Because of such events, Na Ra becomes angry and decides to join Ja Hye’s law firm as an attorney to reveal the truth.

Na Ra asks Joon Hee to help prove In Ho’s innocence. He tries to report about what happened with Mi Jung’s body to the police and calls Na Ra to say that In Ho will be proven innocent. However, Hak Bum and Tae Suk is trying whatever it takes to stop Joon Hee.

Tae Suk and Hak Bum push Joon Hee and his car off a cliff to conceal the truth about what happened. After doing so, Tae Suk and Hak Bum decide to create an alibi. Ja Hye and Young help each other out while investigating Joon Hee’s accident alongside with Mi Jung’s death. Meanwhile, Joon Hee’s body and car gets found.

Tae Suk tries to stop the police from running a DNA test on Joon Hee’s body. Young’s instincts tell him that the body may have been swapped, so he tries to make the DNA test happen no matter what. Meanwhile, several masked men attack Young.

Ja Hye and Na Ra find a clue leading to Seo Joon Hee’s whereabouts. Tae Suk eavesdrops on Young as he tells Joon Hee’s father about the DNA test results. Dong Bae and Young find the manufacturer of the badge Ja Hye gave him. Meanwhile, Tae Suk orders Hak Bum to sell the car they drove on the day they attempted to kill Joon Hee.

As Dong Bae disappears with the truth about the missing case of Seo Joon Hee, Dokgo Young becomes furious and chases after him. After some searching, Young finally catches up with Dong Bae, but he manages to escape again. Meanwhile, Tae Suk and Hak Bum put a tail on Young to find where Joon Hee is.

Ja Hye and Young meet each other at Sunshine Nursing Home. They are suspicious about each other but are able to check that Joon Hee is still alive and kept there. Hak Bum’s car dealer finds out about the video on his dash cam and tries to threaten him to get money. Meanwhile, another attempt to abduct Joon Hee is made.

Someone new visits Gangdong Precinct and looks into the murder case from Paju. Hak Bum asks for Tae Suk’s help to take care of his car dealer, Kim Byung Gi. Young finally manages to catch up with Dong Bae. After hearing what has happened to Dong Bae, Young visits Ja Hye to share what he found out.

After killing the car dealer, Tae Suk forges his own alibi and makes the investigation head for Hak Bum instead. Tae Suk uses this to threaten Hak Bum and make him do as he orders. A woman visits Young and says Byung Gi has disappeared. She suspects that it has something to do with In Ho’s case. Meanwhile, Byung Gi’s car has been found.

Young tries to ask Hak Bum if he knew anything about Byung Gi’s disappearance, but Hak Bum refuses to answer. However, Young finds a clue during his investigation elsewhere. Na Ra finds Kim Jung Soo, the surgeon at Daemyung Hospital, acting odd. Meanwhile, Ja Hye reveals a new suspect on In Ho’s first trial to reveal the truth of Yum Mi Jung’s murder.

Kim Jung Soo tells the court about what happened to Kim Soo Hyun 10 years ago. Due to the reasonable doubt in finding In Ho guilty, he gets acquitted. Hak Bum is not sure if Byung Gi is really dead or not, so he and Tae Suk go back to where they buried him. Meanwhile, Young starts to investigate Jung Soo as a suspect for the murder of Yum Mi Jung.

Young continues to investigate Jung Soo. In Ho, Hak Bum, and Tae Suk visit Joon Hee together and talk about what happened. As a suspicious video clip of Jung Soo leaving the Stellarium Villa in the middle of the night is found, Young gets surprised by an unexpected turn of events. Meanwhile, In Ho receives a USB from Byung Gi’s colleague.

Ja Hye delivers a Demand for Fulfillment of Obligation as Kim Byung Gi’s legal representative to Tae Suk. Young finds a strange drawing in Kim Jung Soo’s house and starts to look into what it leads to. Meanwhile, In Ho receives a text message from Byung Gi to meet, and to pay him two million dollars.

Young realizes that the numbers on the strange drawing from Kim Jung Soo’s house was interpreted wrong. After learning that Ja Hye was at the trial of Kim Soo Hyun 10 years ago, Young meets up with her. Meanwhile, Na Ra sees Dal Rae playing with a suspicious USB and checks what’s inside.

In Ho follows Hak Bum and sees that his friends have gone too far. Hak Bum sees Ja Hye leaving his class and chases her to see why she was there. Young finds evidence that Ja Hye was at the site where Tae Suk was found with Hak Soo’s body. Meanwhile, In Ho invites Tae Suk, Hak Bum, and Ja Hye to have dinner together.

It turns out that In Ho has invited Ja Hye and Joon Hee to dinner along with Hak Bum and Tae Suk. Hak Bum and Tae Suk are surprised to see that Joon Hee has awoken. Meanwhile, Young receives a call from Suk Soon, but Suk Soon suddenly hangs up after realizing that someone has followed her.

Ko Suk Soon is found in Taein. Tae Suk tries to talk with In Ho, but In Ho stands stubborn. Joon Hee is visited by Tae Suk, but Tae Suk is still nervous that Joon Hee might remember anything related to his abduction. Meanwhile, Young continues investigating the case, but things get complicated.

Kim Jung Soo is arrested for the murder of Ko Suk Soon, and Ja Hye comes to be his attorney. However, he refuses Ja Hye’s help whatsoever. Na Ra finds that Joon Hee has not lost his memory and is pretending it. In Ho realizes that Na Ra is pregnant with another child of his. Young discovers that there was more than the case of Kim Soo Hyun behind all these murders.

Young finds Tae Min Young and questions him, but Min Young only says he has nothing to do with them and refuses to say anything more. It turns out that Kim Jung Soo has killed Yum Mi Jung to seek justice himself. Meanwhile, Young starts to think that Dong Bae might have something to do with the recent events.

The regional investigation unit takes away the case on Yum Mi Jung, Ahn Hak Soo, and Kim Byung Gi from Gangdong Precinct. Tae Suk tells Hak Bum to search In Ho’s house for the USB which has the recordings from Hak Bum’s dash cam. Meanwhile, Na Ra sees Hak Bum in her house, but Hak Bum makes her collapse in pain.

Young asks Jung Soo about Jung In Ae and what Dong Bae has to do with him and Ja Hye. In Ho becomes suspicious about Ja Hye and tells her to stay away from his family. Joon Hee tells Hak Bum and Tae Suk that they should be responsible for what they did at least now. After hearing this, Tae Suk and Hak Bum plan to kill Joon Hee.

Young visits Dong Bae's mother again and asks her how she could be close with Jung In Ae. Young sends a colleague to gather more information about Choi Ja Hye. Hak Bum tries to kill Joon Hee, but he finds himself being unable to finish the job. Meanwhile, Dong Bae visits Ja Hye's house and finds it being turn upside down.

In Ho goes to Ja Hye's house, thinking he would see Dal Rae there. However, he runs into someone he wasn't expecting to see. Furious, Young sets up a trap to catch the culprit.

In Ho wants to turn himself in, but Joon Hee gets threatened by Tae Suk. Before turning himself in, In Ho sees Na Ra and his daughter one last time. However, he gets a change of heart after talking with Tae Suk.

Hak Bum fathoms Tae Suk’s plots against him and others, preparing counterattacks. Young unveils Ja Hye’s crimes and puts her into custody. When Young interrogates Ja Hye, she keeps silent.

Ja Hye faces trials after being accused of her alleged involvement in the Roman Numeral Serial Murders. Na Ra finally uncovers Ja Hye’s true identity and understands her motives. Ja Hye tells Na Ra that the truth will be overwhelming, but Na Ra insists on defending her.

The truth told by Ja Hye is hard to believe for Na Ra. With what Ja Hye told her, Na Ra studies the past incidents and learns about the truth. Meanwhile, the three friends, Hak Bum, Tae Suk, and In Ho, meet up at the penthouse.

The trial on Ja Hye comes to a close with both parties presenting witnesses and evidence. Hak Bum, furious with Tae Suk's efforts to shift the blame, decides to take action. Meanwhile, Ja Hye gets ready to finalize her revenge once and for all.

At the cottage where Hak Bum and Joon Hee were drinking, Tae Suk arrives. The tension rises and Hak Bum pulls out a gun. Meanwhile, Young is wondering what Ja Hye is up to.

Ja Hye airs the last episode of her show, going public with everything. While interrogating Tae Suk, the prosecutor in charge hears the news as well. When it gets aired, Young tries to locate her.