Jae Kyeong tries to figure out how the rice shop owner was killed. Based on his calculation, it took the culprit two minutes to kill the man and destroy all evidence. That is quite an impossible feat. While investigating, he encounters a homeowner. After questioning her, she reveals that a taxi was parked in front of her house that morning but she didn’t see the driver’s face. Jae kyeong figures out that the culprit must have been heading to Pilo dong but he gets into a disagreement with his rival inspector Yoo who argues that the case is his and Jae Kyeong should stay out of it. Jae Kyeong tells him that the case is related to Park Jun seo and that it’s about drugs but Inspector Yoo mocks and belittles his thesis.
Nevertheless, Jae Kyeong enters the crime scene. Ignoring inspector Yoo’s yellings. Checking out the scene, he figures out that the killer is an amatuer and that he wiped out the surveillance for a reason he cannot comprehend.
Meanwhile, Yun ho is speaking to his friend from the taxi agency about a certain person he is looking for, Noh gyu min who dropped Park jun seo at the construction site. While providing information, Jae Kyeong, who is driving to the agency, nearly hits the friend. Jae Kyeong apologizes. He parks his car and starts searching through the taxis, presuming that the taxi driver who dropped Park Jun seo off at the construction building could have been his killer.He calls the woman he had questioned before and she tells him the taxi was silver colored.
He then questions a staff at the agency about the taxi that dropped Jun seo off and the woman informs him it’s a man Noh gyu min but he quit the previous day. She gives him the address and he asks her to inform him if someone else comes asking for Noh gyu min.
He goes to Noh Gyu min’s apartment but the landlord informs him Noh gyu min moved out the previous day and asked him to give him his deposit once another tenant moves in, Jae Kyeong then asks the landlord to inform him if Noh gyu min calls.
Yun ho drives past and sees him leaving Noh Gyu min’s house. He then calls Chi hyeon and tells him what he did. Chi hyeon gets furious and yells they should meet at Pilo dong. Meanwhile, on arriving at his apartment, Jae kyeong sees a box delivered to his door. It’s the yellow pills and he tries to get rid of it by stamping on it, even smashing the pills with a hammer but his urge is too strong. He’s so disoriented that he ends up crying like a baby.
Inspector Yoo informs Tae Jin about the recent murder and Tae jin is particularly shocked about the CCTV they discovered but the footage was completely destroyed in the fire. Tae Jin asks if Jae Kyeong saw the footage but inspector Yoon replies he probably didn’t and that he wants to connect this case and that of Park Jun Seo together but Tae Jin intimidates him by telling him the cases are different. He also warns him to stop calling whenever a new case occurs.
At Pilo dong hideout, Chi hyeon hits Yun ho until he’s satisfied then gives him tissue to wipe away his blood. He then asks if he got rid of every evidence including his hair sample. Yun ho replies that he did. Chi yeon berates him for killing the man but Yun ho explains he had no time and that everything he is doing is to secure their survival. They then wonder how Lee Myung Uk’s corpse was kept in his house and who must have done it.
Meanwhile, Jae kyeong checks the usb the rice shop owner gave him and sees two cars driving past after Jun so’s murder. Suspicious of Km Chang soo, he calls Si jung instead and asks her to run the license plate number of the car.
Yoon jin who is bothered by Ji yeon and Tae jin’s affair tells her partner Woo sung about it under the guise of a story but Woo sung soon figures out that it’s real and she asks him to look into the case.
At Jun ho’s office, Tae Jin informs Jong su and Chi hyeon about the murder. When Jong su hears Jae Kyeong is involved, he becomes worried. Tae Jin asks Chi hyeon if he knows anything about the case but he denies it. Jong su who is tormented by the news reminds the two that they have been waiting for twenty years. If he doesn’t become the chairman of Keumhyung pharmaceutical, they will all be ruined. He doesn’t feel he can trust any of them.
Woo sung starts investigating Ji yeon since Yoon jin promised him a hundred thousand dollars. Meanwhile, Yoon jin goes to Woonjung hospital to investigate the case of Park Bok rye who died after a medical incident. She ends up running into the hospital director, a young woman. After questioning her, the woman acts clueless and cleverly denies everything, stressing that the injection administered to Park Bok rye was deemed okay by the health ministry. She claims that people spread rumors all in a bid to tarnish the hospital reputation. She leaves after telling Yoon jin to inform her before concluding anything.
Ms Yoon is informed of Jin uk being wanted. When Jin uk discovers it, he is afraid that Ms Yoon would use the opportunity to push him aside and deal directly with the doctor. He tells his friend to be careful of new people.
Yoon jin comes to see Jae Kyeong with food. But he ends up telling her about the murder and how everything, including his addiction to drugs is all connected. Someone is stopping him from revealing the truth. He warns her to step away from the case so she wouldn’t be a target and forget about the insurance money she would gain. Yoon jin then shows him the text she also received from Jun seo and tells him that although she came here for information, she also came to check up on him because she’s worried he will collapse and no one would be around to help him. She tells him to take care of himself, not her and forces him to eat. Jae Kyeong is quite impressed by her. However, she still wonders why Jun seo was dealing with drugs. Also, she knows that Jae kyeong came back to the station after discovering Lee Myung uk’s body to steal the yellow pill. Jae Kyeong admits that he couldn’t control himself and might even end up taking it again.
However, Joo song suddenly calls to inform them that he has information on Audiophile, the company that Park Jun seo formed. It was located in Pilo dong but something seems off about it. On their way, Joo song asks Jae Kyeong what Park Jun seo told him the day he visited. Jae kyeong replies that he said he would make everything right. Joo song then adds that Park Jun seo must have been feeling guilty for making him transfer school many years ago but Yoon jin cautions him for speaking too much knowing that topic would upset Jae kyeong.
They arrive at the address but are surprised to see a young boy who appears to still be in high school. His name is Min hyun woo and when they tell him about Park Jun seo’s death, he appears upset. He takes them to a room and says he was expecting them. They ask how he knew Park Jun seo. He replies they just met in passing. He lives with his grandmother and is a delivery guy. Jae Kyeong then asks if he ever delivered drug but he denies it. He asks if he knows Lee myung uk but he doesn’t.
Meanwhile, Joo song is speaking with Min hyun woo’s grandmother. He learns that her son was tricked into selling his pig farm for a small amount unaware that they were building a commercial building. She discloses that her son Min seung uk hasn’t been home in a long time. Jae kyeong and Yoon jin meet them and the grandmother praises Park Jun seo for being such a good man who always helped their family when they were in need. She asks about his whereabouts and Jae Kyeong bluntly tells her he passed away. After saying that, he leaves but Yoon jin and Joo song chase after him. Joo song is especially annoyed with how he behaved, showing no empathy for people. Jae kyeong replies that he has no time and he shouldn’t care since the woman wasn’t Park Jun seo’s family.
However, Joo song is angry at how he easily cuts off people, not caring about anyone but himself. He did the same to a friend of theirs Cha Kyung Tae and now, he’s doing the same with Park Jun seo. He yells that he never considered Park Jun seo. If he had given him time back then, he would have never had ro transfer schools. Min hyun woo’s presence ends the conversation. In the car, the tension is high. Joo song drops Jae Kyung off and Yoon Jin scolds him for what he did. Although they both agree that Jae Kyeong only cares about himself. She asks him.to drop her off and Joo song is upset she isn’t having dinner with him but Yoon jin reminds him she wanted to eat with the three of them (Friendzone)
Woo sung is surprised to see Jae kyeong coming to see Ji yeon. He informs Yoon Jin who is curious. Jae kyeong asks permission from Ji yeon to look for something which has to do with his investigation. She agrees. He asks her to bring any laptop or usb she has and while she’s gone, Jae kyeong recongnises an old stereo set which was used during their audiophile days in high school. He is surprised Park Jun seo still had it. Ji yeon brings him Jun seo’s laptop. Except for videos with his late daughter, there is nothing else. But he immediately notices that Ji yeon is nervous. Yoon jin then meets Woo sung outside who is still waiting.
Jae kyeong is about to leave the apartment but suddenly, Tae Jin enters, freezing in shock upon seeing him.
The epilogue shows the classroom from the past. Everyone is mourning Cha Hyung Tae’s death. But Park Jun seo seems particularly affected by it such that Jae Kyeong confronts him about it. But both are unaware that a young Noh gyu min (the taxi driver who is missing) is watching them argue as Jae kyeong asks Jun seo if the fire that burnt Cha hyung tae’s house was an accident or not but Park Jun seo refuses to give him an answer and leaves angrily. We suddenly see a name label ‘Won jong soo’ in No gyu min’s hand.