Episode 6 of A Killer Paradox revisits the harrowing moment when Tang, on the cusp of entering the elevator, felt a chilling sensation creep up his neck upon spotting the man within. After Tang nonchalantly walked away, the man, offended by the perceived disregard, vengefully broke into Tang's apartment, unleashing a fire extinguisher in a fit of rage, leaving the premises drenched and chaotic. Presently, he sits in police custody, facing questioning by Nan-gam and a seasoned Busan detective.
The scene shifts to Song Chom, who leisurely removes a glove, revealing fingertips that are eerily black. As he applies a healing ointment to his skin, he converses with some nearby cats, muttering about ridding the world of its vile inhabitants. Meanwhile, Yong-jae, confined to his hospital bed, dials Nan-gam, venting his frustration over the ongoing situation. He casually mentions glimpsing Song Chom lurking outside Sang-min's apartment, adding another layer of mystery.
Nan-gam, caught between duty and personal turmoil, urges Yong-jae to prioritize his recovery. Nan-gam is currently at the hospital where his father lies critically ill. His mother scolds him for answering calls at such a sensitive time. The attending physician presents a harrowing dilemma: whether to opt for life-sustaining measures that would inevitably compromise his father's quality of life.
Elsewhere, Tang finds himself on a train, witnessing a man insultingly groping the girl seated beside him. Despite the clear injustice unfolding, Tang remains a passive observer, even as she loudly protests her ordeal. Consumed by guilt or inertia, he subsequently seeks refuge in the familiarity of a cybercafe, where he indulges in video games—a habit left behind in his youth when he neglected his studies.
Roh Bin returns home to an unwelcome surprise: Song Chom already awaiting him there. Chom, Bin's former collaborator, expresses his desire to meet Tang. Bin, informed of Tang's disappearance, reluctantly agrees to arrange a meeting once he reappears. Chom, however, doesn't leave empty-handed; he takes a copy of "Crime and Punishment" from Bin's safe, hinting at a deeper significance tied to his motives. As Chom makes his exit, Bin, driven by impulse, attempts to confront him but is swiftly overpowered.
At the cybercafé, Tang felt a prickling sensation at the nape of his neck as another patron took the seat adjacent to his. Yet, he chose to remain undisturbed and departed without incident. Defying Nan-gam's counsel, Yong-jae made his way to Roh Bin's residence. There, he unexpectedly encountered Chon, who was just about to leave. A fierce scuffle erupted between the two, culminating in Chon forcefully ejecting Yong-jae through a window.
Roh Bin subsequently turned himself in at the police station, insisting that he would only converse with Nan-gam. He unveiled his accusations against Chon, implicating him in the gas explosion tragedy in Busan as well. Meanwhile, Chon found himself trapped in a traffic jam, where he observed a young man and his girlfriend treating a taxi driver with disdain.
Roh Bin offered to unburden himself to Nan-gam completely, provided that the detective assisted him in confronting Chon once more. Nan-gam, however, declined to collaborate with him. On a rooftop, Chon confronted the same couple from earlier, his wrath evident. The young man appeared lifeless, while the woman pleaded for her life, causing Chon to have a last-minute change of heart.
Tang, meanwhile, was haunted by a nightmare featuring Chon. He awoke to the grim news of a fugitive named Lee who had committed a murder. It dawned on him that Lee was the same man who had sat beside him at the cybercafé. Back on the rooftop, Chon departed, leaving behind a confession note inscribed in blood.
The newly appointed police captain visited Nan-gam, recognizing his extensive knowledge of Song Chon. He presented Roh Bin's documents along with details about a Mopko case – the murder of the young couple by Chon. The girl was the granddaughter of the chairman of Buyeon Construction, a prominent company. A promotion awaited the officer who cracked the case. The captain instructed Nan-gam to resume his duties the following day. In the meantime, Roh Bin took matters into his own hands by approaching Buyeon Construction directly to aid in capturing Chon.
He subsequently receives a call from Tang, who harbors a desire to delve deeper into the enigma of Chon. Initially, Bin had extended the same proposition to Chon as he had to Tang, but he soon discerned that Chon harbored a perverted glee for cruelty, devoid of any apparent reason. Tang urges Bin to arrange a meeting, while Chon, immersed in perusing his collection of confession notes culled from his victims, receives a message informing him of Tang's intention to meet as well.
Chon initiates a video call with Tang, guiding him to a dilapidated café. Meanwhile, in a neighboring building, Bin awaits with representatives from Buyeon Construction, who are eager to apprehend Chon. However, upon noticing Tang's location diverting from the intended site, Bin informs the men of the change in plans, necessitating their swift pursuit. His attempts to reach Tang via phone fall on deaf ears.
Inside the decayed café, Tang discovers Chon awaiting his arrival. Chon interrogates Tang about his "hunches," probing deeper into his thoughts. Simultaneously, Bin and the men from Buyeon Construction arrive at the designated location. Bin instructs them to venture inside, but his authoritative tone alienates them, leading them to turn against him, leaving him bound and helpless.
Chon finds Tang's abilities intriguing, prompting Tang to request the return of his book, "Crime and Punishment." Chon, however, refuses, insisting he hasn't finished with it yet, and cautions Tang against placing too much trust in Bin. Instead, Chon propositions Tang to collaborate with him, selecting the deserving targets for elimination. As Chon departs, he places a reassuring hand on Tang's shoulder, and something within Tang shifts, provoking him to lunge at Chon with a knife. Nevertheless, Chon easily subdues him, asserting that Tang is no hero, merely a murderer.
Just then, men from Buyeon Construction intervene, surrounding Chon and allowing Tang to flee. Tang dashes out, securing Bin's release as well. Bin reveals he kept the book not due to mistrust but for reasons unknown. He pleads with Tang to trust him once more. Tang confides in Bin, expressing his fear. Their conversation is abruptly interrupted by the sound of a gunshot echoing from above.
