Episode 12 of The Worst of Evil starts with Jong-ryul threatening to shoot Do-hyung if Jun-mo doesn’t. He asks what Jun-mo’s (Seung-ho’s) relationship with the Narc is and wonders why he hesitates to kill him.
Jong-ryul fires a shot at Do-hyung after which Jun-mo tries to fight him off. Jong-ryul tries to kill Do-hyung but Jun-mo intervenes. He checks on Do-hyung and tries to call the ambulance. As he passes out, Do-hyung asks Jun-mo to never forget that he’s a cop.
Just then, more cops arrive at the scene and help take Do-hyung to the hospital while arresting Jong-ryul. Jun-mo waits outside the operation room for a while and goes back to the Union to check up on Gi-cheul. A while after, the doctors tell Chang-sik that he’s not able to save Do-hyun
Jung-bae bribes Min-goo and asks him to arrest Gi-cheul. Hee-sung is involved with Jung-bae as the two hand over the drugs to the cop, asking him to put Gi-cheul in jail for life for the possession of drugs as well as the abetting of murder.
When Gi-cheul shows up at the Union, Jung-bae mocks him for forgetting about his brothers while he only thinks about his own future.
Jung-bae asks if Gi-cheul even cares about the boys that work for him and their dreams. He claims to be the person that took care of the boys when he still worked with Gi-cheul. Min-goo shows up at the Union and arrests Gi-cheul while he is still shocked by the fact that his friends betrayed him.
On his way out, Gi-cheul is shattered when Eui-jeong sees him being taken away in the police car with handcuffs on. Jun-mo finds out that Gi-cheul was arrested and fury takes over him. He rams into the police vehicle causing it to topple, leaving Min-goo and Detective Go injured.
Eui-jeong,who was following them sees Jun-mo take Gi-cheul away. Jun-mo takes Gi-cheul to a hideout spot while Chang-sik keeps the news of Do-hyung’s death a secret to keep him focused on the mission.
Jung-bae decides to sell off the drugs to their regular buyers but Chang-sik decides to stop him from doing so. He asks the cops to arrest all the regular buyers/drug dealers leaving Jung-bae with no resort but to contact that Japanese buyer – Oyama.
At the same time, Jun-mo stops Gi-cheul from making any rash decisions, asking his boss to trust his plan.
In the hospital, Min-goo finds it odd that Seung-ho has no criminal record to his name. Meanwhile, Kang-san shows up at the Union and meets Jung-bae, demanding money for his product on Hae-ryun’s behalf. He threatens Jung-bae, who then asks to meet Hae-ryun in person.
After being discharged from the hospital, Min-goo meets Jung-bae and Hee-sung who tell him that the best way to find Gi-cheul and Jun-mo (Seung-ho) is by contacting their girlfriends Eui-jeong and Hae-ryun. Hae-ryun meets Jung-bae and gives him the name of the Japanese buyer as per Jun-mo (Seung-ho’s) instruction.
Kang-san wonders why Hae-ryun had decided to double-cross both Boss Oson as well as Jung-bae.
Meanwhile, Eui-jeong is shattered by Do-hyung’s death and notices how Chang-sik had kept the news a secret from Jun-mo. Detective Go shows up at the funeral home and finds out that Do-hyung was pretending to be Jun-mo.
He shares the news with Min-goo who takes the information directly to Hae-ryun.
Hae-ryun is heartbroken but decides to talk to Jun-mo (Seung-ho) first, asking if he was pretending to be kind to her with an ulterior motive.
On the call, Hae-ryun asks him if she should go to China or stay back in Korea. Jun-mo states that Hae-ryun should live her own life by going to Hong Kong.
Hae-ryun understands that Jun-mo has been honest about his feelings for her and decides to kill Min-goo. Kang-san distracts Detective Go which gives Hae-ryun time to flee from Korea.
Jun-mo takes Gi-cheul to the port where the trade is about to take place. Once the Japanese trader takes the drugs in exchange of the money, the cops make a note of the name of the boat that leaves for Japan. Jun-mo reveals himself in front of Gi-cheul and handcuffs him to the steering wheel of the car.
Gi-cheul is shattered by the revelation and doesn’t know what to do. He watches as Jun-mo and the other cops arrest Jung-bae and the gang. Gi-cheul notices that Jun-mo has left the key to the handcuffs on the passenger seat on purpose as well as the key on the car.
The Chinese cops raid Boss Oson’s factory and arrest everyone there. The Japanese cop arrests Oyama just as he accepts the drugs from his dealer. The Korean cops arrest everyone at the Union as well.
Gi-cheul reads in the newspaper that the international projects he had promised to invest in were cancelled due to the lack of funds. Jun-mo visits Do-hyung’s tombstone and pays his final respects to him.
On the drive back, Eui-jeong and Jun-mo discuss what the future of their marriage would look like after the mess they’ve been in.
As soon as they arrive home they find Gi-cheul waiting for them. Gi-cheul is more than just shattered upon finding out that he was betrayed by not one but two of his most trusted people. He tells Eui-jeong that what she had done to him was also sinful in the eyes of God considering how she was faithful.
Eui-jeong explains that she was okay living with guilt for the rest of her life. Gi-cheul decides to amplify her guilt by killing himself. Gi-cheul tries to shoot himself in the head but Jun-mo shoots him in the chest to save Eui-jeong from the trauma.
Jun-mo tries to call the ambulance to help Gi-cheul but holds back when he sees Eui-jeong concerned about him. The episode jumps to the day of Jun-mo, Eui-jeong and Do-hyung’s felicitation for their contribution to the operation.
Jun-mo accepts the award and salutes Do-hyung’s photograph as the late cop’s wife receives the award on his behalf. He seems distant from Eui-jeong. The show ends with Jun-mo visiting Gi-cheul’s grave.
As glad I was that things have finally ended for good from Jun-mo’s perspective, my heart breaks for what happened with Gi-cheul. I wish things would not have ended the way they did for him and we could have hoped to see him come back seeking revenge on Jun-mo and Eui-jeong after what they did to him.
The final moments of the show emphasize the brotherhood between Jun-mo and Gi-cheul as the two smoke cigarettes and walk the streets of Gangnam in their suits. If only there was an alternate universe where both Jun-mo and Gi-cheul work together as a team.
As challenging as Eui-jeong and Jun-mo’s marriage was throughout the entire season, it seems like she really had feelings for Gi-cheul for a moment. Considering that as well as Hae-ryun’s love for Jun-mo, it would have been nice to see both couples have some way to make it back to each other, considering how unhappy Jun-mo was around Eui-jeong’s family.