Episode 5 of The Worst of Evil starts with Jun-mo holding up a gun to protect Gi-cheul. Both men try to fight off the thugs while Gi-cheul wonders which member of his gang would have betrayed him like this. He reloads his gun with more bullets but Jun-mo (Seung-ho) shows up in front of him, protecting the guy from being stabbed with a sword. The sword slices through Jun-mo’s back.
At the same time, Jong-ryul shows up at the site and helps Gi-cheul and Jun-mo flee while the latter of the two is taken to the hospital due to his injuries. A flashback shows how the Jaegeon group goons reached out to Jong-ryul, asking him to betray Gi-cheul but the former refused to do so.
The next morning, Gi-cheul asks Jung-bae to wait outside while he waits in Jun-mo’s room, worried for him. He asks Jong-ryul to look into the matter and find out who among Jung-bae, Hee-sung and the others is the traitor. Jong-ryul goes asking around and learns that while the rest of the goons, including Hee-sung, have their alibi checked, Jung-bae’s flat tire looks manmade.
A while after, Jun-mo wakes up in the hospital and Eui-jeong finds out. She argues with Chang-sik and accuses him of putting Jun-mo’s life in danger. She asked to be included in the mission more actively as she wanted to make sure her husband was okay. Meanwhile, Gi-cheul thanks Jun-mo (Seung-ho) for saving his life not once but twice and reveals that he trusts him now.
Since the “fishing” trip had been bust, Kanemoto asks Oyama to keep reaching out to Gi-cheul in order for him to collect his order. Oyama finally gets to Gi-cheul and gives him an earful for messing up the time of their original hangout. Gi-cheul talks to Kanemoto and tells him that he was being tailed and that someone ambushed him when he was on his way to collect the order.
Kanemoto reveals that he too was being tailed and asks him to deal with the traitor. Meanwhile, Jun-mo tries to reach out to Do-hyung but is unable to do so as he is transported in an ambulance after his recent recovery. When left alone, Do-hyung shows up to see Jun-mo and the latter reveals how Gi-cheul was going to kill the traitor that night.
Jun-mo asks Do-hyung to save the real traitor before Gi-cheul’s men can reach him. Yong-dae notices Do-hyung leaving the ambulance that Jun-mo (Seung-ho) is in but he does not make much of it. That night, Gi-cheul gets a call from the traders, asking him to collect the order in two days. He agrees to do so and goes out to find the traitor amongst the members of his gang.
Since Gi-cheul called in the boys to see him that night, the only three people missing were suspected to be traitors. Jong-dae tells Jun-mo that Kyung-jin, Hee-sung and Jong-ryul are the only three missing people. Just then, Hee-sung shows up and Gi-cheul realises that Kyung-jin is the traitor. Gi-cheul asks Jong-ryul to go and find Kyung-jin to bring him to the men’s club.
At the same time, Do-hyung takes a few cops along to bring Kyung-jin to the police station in order to save him from Gi-cheul. However, Jong-ryul gets to Kyung-jin first and takes him to Gi-cheul. The goons beat him up and Gi-cheul asks Jong-ryul to kill him off. Jun-mo intervenes and beats the traitor up. He tells Gi-cheul that beating Kyung-jin up is enough punishment and asks him to be sent away.
Gi-cheul warns Kyung-jin and lets him go. Gi-cheul then takes Hee-sung, Jung-bae, Jong-ryul and Jun-mo (Seung-ho) and tells them about the upcoming order. Jung-bae is shocked that Gi-cheul was allowing Jong-ryul and Jun-mo in their private conversation. Gi-cheul argues that the Japanese traders are furious with them for missing their delivery and that they need all the help they can get.
On the contrary, Chang-sik learns about a Korean resident, Professor Yoon Won-gil who had left for China and hadn’t returned ever since. He tells Do-hyung that Gi-cheul was involved in a smuggling trade between both Japan and China which further complicates things. The cops seek help from the Chinese police and issue a lookout for Professor Yoon who was hiding in China.
The next morning, Eui-jeong calls Gi-cheul and asks him to see her the following day. Gi-cheul is reluctant because of the order but still agrees to meet Eui-jeong. He tells Jung-bae and Hee-sung that he is not going to be there to meet the order from China and adds that Seung-ho (Jun-mo) will be taking care of it.
The two boys are not happy with the news. Jong-ryul and Jun-mo meet Gi-cheul in his office and tell him that they need to be careful of Jung-bae as it is possible that he too is involved with his enemies. Gi-cheul tells them that Jung-bae is like a brother to him and asks Jong-ryul to find out more and be careful when he goes about finding the truth about Jung-bae’s involvement in the attack.
That evening, Gi-cheul has a drink with Jung-bae while Jong-ryul threatens one of the goons who are in the hospital. Jong-ryul tries to check if the goon knows Jung-bae. As Gi-cheul and Jung-bae share drinks, the two take a walk down memory lane and recall their early days in the business.
While in confidence with Gi-cheul, Jung-bae offers to go meet the Chinese client but Gi-cheul refuses the request. Jong-ryul calls Gi-cheul to tell him that Jung-bae is clean and Gi-cheul finally takes a sigh of relief. At the same time, Jun-mo goes back home to check on Eui-jeong as he apologises to her for not being there after her mother passes away.
The couple shares a meal together when Jun-mo promises to come to visit her often as Gi-cheul has started trusting him now. The next morning, Jung-bae tells Hee-sung that Gi-cheul trusts Jun-mo (Seung-ho) too easily and senses something fishy about his involvement with Eui-jeong, a cop.
That day, Seung-ho goes to the docks to pick up the Chinese client, hoping to meet Professor Yoon. Instead, he is met with a young Korean-Chinese girl – Lee Hae-ryeon who has travelled along with her bodyguard. Meanwhile, Gi-cheul meets Eui-jeong at their old church and offers his condolences for her mother’s death.
On the other hand, Jun-mo tries to make small talk with Hae-ryeon but is met with taunts. He drops Hae-ryeon at the hotel and tells Do-hyung how he was not able to extract any information about the ongoing deal. Do-hyung tells him that Gi-cheul is with Eui-jeong.
The news infuriates Jun-mo, and he asks the officers to put an end to this operation as soon as possible in order for him to go back to his normal life. The episode ends with Jun-mo going inside the restaurant that Hae-ryeon is staying at, where he notices Oyama inside the hotel with some luggage. Although, Jun-mo has no idea who Oyama is.
Everything is going as per the cops’ plan but I am worried that this operation will do more than just physical damage to Jun-mo and his family. Seeing how Gi-cheul is clearly in love with Eui-jeon, and that he is finally trusting Jun-mo, he will be badly hurt when he learns that both Jun-mo and Eui-jeong have betrayed him.
I was sure Jung-bae was a traitor but it looks like he is a loyal follower of Gi-cheul. However, Gi-cheul’s trust in Jun-mo/Seung-ho will surely be the cause of a potential argument between the gang leader and his two trusted men.