Episode 2 of "Gangnam B-Side" unfolds with the dramatic arrival of a cleaning crew at a hotel room, where they soon discover the absence of Jung-hwa's body, plunging them into a state of shock and panic. Her tough, menacing dealer, Psyche, swiftly informs her client and murderer, Noh Joon-seo, who remains relentlessly fixated on locating Jenny. Unbeknownst to many, Joon-seo doubles as Jjuni Boy, a beloved yet cocaine-addled K-pop idol.
In a separate twist, Gil-ho strategically dumps Jung-hwa's body at a subway station, orchestrating a bold move to draw the authorities' attention. Dong-woo, who recently joined the Gangnam squad, faces an icy reception from his new colleagues, forcing him to remain on the fringes of the investigation. Undeterred, Dong-woo embarks on his own inquiry, reaching out to Jang-ho, now reduced to a lowly gangster. Jang-ho initially distances himself from Dong-woo, but their shared past as ex-colleagues, coupled with Dong-woo's willingness to cover for him, persuades Jang-ho to aid in tracking down Gil-ho. Through Jang-ho, Dong-woo learns that Gil-ho has transformed into a pimp, with Jenny and Jung-hwa serving as his top assets.
Gil-ho, harboring a grim plan to shield Jenny and exact revenge on Jung-hwa's killers, finds an unexpected ally in Psyche, who proposes a deal: Jenny in exchange for whatever Gil-ho desires from Joon-seo. Pretending to agree to the terms to confront and eliminate Joon-seo, Gil-ho heads back to the arcade. However, a devastating blow awaits him—Jenny has vanished, having learned of Jung-hwa's murder through the news.
Meanwhile, Prosecutor Min stumbles upon CCTV footage revealing Gil-ho disposing of Jung-hwa's body. The chief prosecutor, Tak, hastily declares Gil-ho as the prime suspect and assigns Min to collaborate with Major Crimes for his arrest. Min is astounded by the precipitate nature of their actions.
Her astonishment deepened when the captain of Major Crimes materialized—a figure none other than the former Chief Yun, whom Dong-woo had apprehended in the first episode. Despite the urgency to conclude the case, Min remained unfazed, commanding Tak to recompense her for the hazards she faced. Tak, indulging her request, still made it clear that he was in command.
Elsewhere, Joon-seo's superior, CEO Lee, vented his frustration on Joon-seo for allowing the Jenny situation to spiral out of control. Meanwhile, Psyche notified Gil-ho through a text that he had arranged a meeting with Joon-seo at Yeoksam, which was actually a setup. To ensure his scheme succeeded, Joon-seo bribed Yun to turn a blind eye to his plans to eliminate Gil-ho and Jenny.
Simultaneously, Dong-woo, informed by Jang-ho's gang, also became aware of the impending confrontation in Yeoksam, as all of Gil-ho's adversaries had been alerted to the trap. Captain Yun instructed Prosecutor Min to bring a warrant to apprehend Gil-ho in Yeoksam.
Upon Gil-ho's arrival, Psyche was irritated to find that Jenny wasn't with him. She stalled by mentioning the tape Jenny and Jung-hwa had recorded of their clients, which stunned Gil-ho. Thugs soon emerged, sparking a fierce battle as Gil-hosingle-handedly defeated them all. Psyche streamed the chaos for Joon-seo's enjoyment. Noticing this, Gil-ho lunged for Joon-seo, but two bodyguards ambushed him, stabbing him.
Additional thugs descended upon the scene, but Dong-woo intervened just in time to rescue Gil-ho. Psyche seized Gil-ho's knife, while Joon-seo visited CEO Lee, romanticizing about their shared aspirations to conquer the world, leaving Lee bewildered. Joon-seo's subordinate appeared, disguised as a fan, and assassinated Lee. Joon-seo used Lee's phone to inform Mr. Choi that it was time for Gangnam Trading Company to have a new CEO.
As Captain Yun's team spotted Dong-woo's car and followed him, Dong-woo informed Prosecutor Min that they needed to revamp their narrative, irritating her. In the car, Dong-woo insisted on knowing whether Gil-ho had killed Jung-hwa and Jenny, but the wounded man remained silent. Instead, he mocked Dong-woo's assumption that Gangnam Trading Company had fallen after Dong-woo's three-year-old drug bust.
Yun's team interrupted them, surrounding them on a bridge. The tension mounted as Yun couldn't bring himself to kill Dong-woo, who refused to surrender Gil-ho. Prosecutor Min finally arrived, demanding answers, but the distraction provided the perfect opportunity. With a daring leap, Gil-ho plunged into the river, bringing Episode 2 of Gangnam B-Side to a dramatic climax.
