A Killer Paradox episode 5 follows Lee after his unlikely partnership with Only For Heroes, aka Roh Bin. His life has certainly taken a dramatic turn since we first met him, after an accidental murder in self-defence led him down a dark path.
By the time we catch up with him in this episode, Lee has moved to Busan under a fake name where he continues to target criminals and immoral people, having gotten away with murder several times by this point.
But Detective Jang hasn't forgotten about him, quite the opposite, and he's becoming obsessed with his pursuit of Lee Tang. He keeps evading his grasp but he's hoping he can finally track him down, putting an end to this case for good.
Here's what happened in A Killer Paradox episode 5...
Lee moves to Busan
This episode starts with a clip of a young woman named Gyeong-a whose sex tape was leaked, resulting in a public scandal that forced her to move cities. Meanwhile, Roh Bin makes Lee a fake ID giving him a new identity; Gyeong-su.
Lee is now based in the city Busan and has killed again. We learn his most recent kill was a professor who slept with a student and then murdered her when he found out she was pregnant. Bin narrates this segment claiming that Lee's murders are "an essence of pure good".
Since moving to Busan, Lee got himself a new job in a supermarket where he works as a fishmonger. It is revealed he worked with Gyeong-a, who seemed to be wary of male customers in particular. She gets into a fight with a customer who is asking for a refund, and she argues she's not entitled to one.
The customer goes outside to her car and finds Lee smoking. He knows she's been lying about the situation, and she actually stole the product she wanted refunded. Gyeong-a watches the two of them talking, and joins him for a smoke later that day where she expresses they're both similar because they're "running away from their past".
Meanwhile, Detective Jang is going through a lot since the ordeal with Lee and Bin. His colleague Chung-jin visits him, where he finds out he's kept Rex, the dog of one of the murder victims. In addition to this, Bin has a restraining order against Jang because of the assault that was broadcast online. Yong-jae also visits and has a go at him for not keeping him in the loop about Roh Bin.
Yong-jae tells Jang that while working on another case, he spotted footage of Lee traveling to Busan, which leads them to examine some murders that happened there. Agreeing it is a very convenient coincidence, they visit Lee's family and suggest they file a missing person's case.
However, Yong-jae decides to take a more blunt approach and mentions what's been happening to Lee's family, and both his parents and sister have a hard time believing that he could be responsible for one murder, let alone several.
Eventually, his parents come to the police station and register Lee as a missing person, which helps Detective Jang officially go to Busan to look for Tang. The Busan detectives don’t seem to think Lee could be the culprit of the professor’s murder, so Jang presses them for information on other unaccounted deaths.
Meanwhile, Gyeong-a is at work when she gets a call from her schoolmate named Sang-min. He says a sex tape of him also got leaked and he was extorted for it. They meet and Sang-min admits he got her number from a cop, but being in a similar situation, he didn’t know who else to go to.
He claims his parents don’t want to do anything with him and his girlfriend broke up with him, so he's feeling isolated. Gyeong-a allows him to stay over and asks him if he wants to share the bed.
Sang-min is actually lying and is on perfectly good terms with his girlfriend and is deceiving Gyeong-a. He makes an excuse to visit Busan again, but when he’s near the supermarket, Lee overhears him talking to his girlfriend on the phone. Gyeong-a continues to spend time with Sang-min.
Gyeong-a seems to be happy with Sang-min and even suggests going back to Seoul. However, she ends up checking his phone and finds evidence that he has a girlfriend. It is revealed he was only interested in pursuing her because of the sex tape and got her number from the empty delivery parcels outside her house.
They get into a fight and Sang-min ends up choking her to death. Later that day, Jang and Lee separately see the news of a massive fire in Gyeong-a’s building. Following this, Jang tries to convince the local authorities to focus on what happened.
At work, Lee learns that Gyeong-a died and seems shocked to learn about it. In the market, Detective Jang arrives. Lee rushes to the back of the store where a shady cop Song Chon is waiting for him.
Lee realizes this man has killed many people. By the time Jang gets there, both have disappeared. He asks Lee's employers for his address, hoping to find him there.
Meanwhile, Sang-min has been diagnosed with gonorrhea. He speaks to his girlfriend, who also has it, and confesses she has been cheating on him. He goes home to see Song Chon waiting by his front door.
Chon interrogates him like a regular cop. When he realizes that Sang-min did kill Gyeong-a, he starts pulling out equipment from his bag and it is clear he is hiding something darker.
After spotting Jang, Lee is now on the run. He calls Roh Bin and says something feels different this time, and he is told to lay low and keep his phone off.
Chon tells Sang-min about Lee and how he’s been looking for him. Sang-min ends up writing a confessional note about the murder before Chon kills him and then cleans the place up. He sets the apartment on fire before leaving.
Jang and a local Busan detective go to Lee's new residence. Around the same time, Yong-jae and the other cop go to Sang-min’s place, where they see Song Chon leaving. Jang opens the door to see Tang’s house filled with smoke while Sang-min’s kitchen explodes, hitting Yong-jae who is right at the front door.
