Episode 5 of "Karma," titled "Rewind," kicks off with Eyewitness grappling with intense pain, while the taxi driver watches him warily from the corner of his eye. The scene abruptly shifts to the moment when Eyewitness ends Sang-hun's life, appropriating his glasses, coat, and vehicle for his escape. Meanwhile, Sang-hun's wife, furious at PI Hwang's perceived slowness, lambasts him over the phone. Hwang's assistants finally arrive, tardy as ever, handing him the camera containing incriminating evidence of Sang-hun's infidelity with Yu-jeong. Hwang's delight quickly turns to astonishment as he scrolls through the photos, stumbling upon images of Eyewitness committing the murder.
Ten hours before the inferno that would rock their world, Jae-yeong instructs Gil-ryong to meet him at a secluded parking lot. With escape in mind, Gil-ryong swiftly arranges passage to China by boat, intending to flee once he secures the money. As he prepares to depart, Eyewitness materializes, greeting Gil-ryong warmly as an old comrade from their shared cellblock days.
A flashback to six months prior reveals Eyewitness and Gil-ryong's prison career, their cells adjacent. As Eyewitness's sentence draws to a close, he promises Gil-ryong that he'll always be there if needed. Yu-jeong, their mutual classmate and Eyewitness's awaiting accomplice, enters the picture. She thrives on scams, requiring Eyewitness's unique skills to manipulate and extort wealthy marks. A montage unfolds, depicting Yu-jeong seduces affluent men while Eyewitness extracts their fortunes through cunning and guile.
Months later, Yu-jeong crosses paths with Sang-hun for the first time, just as Eyewitness receives an urgent call from Gil-ryong, requesting his assistance in a scheme to cash in on Jae-yeong's life insurance. With this introduction, the intricate web of deceit, betrayal, and unintended consequences begins to tighten its grip.
The eyewitness, pivotal in unveiling the true extent of Gil-ryong's payout, also acknowledges Jae-yeong as a sorry figure from his school days. On that fate-laden evening, Dong-sik, burdened by unforgivable sins, offers a prayer for his son, his hope resting solely in divine mercy, despite a nun's attempt to offer him solace. His girlfriend, interrupting his contemplation, mentions a birthday celebration organized by the parish in his honor. He politely declines, citing his lingering trauma from a hit-and-run incident. Undeterred, she resolves to bring him a slice of cake anyway.
As Dong-sik ventures into a dimly lit alley, the eyewitness, driving with reckless abandon, strikes him twice, leaving him gravely injured. Gil-ryong rushes to his aid, only for Dong-sik's girlfriend to arrive with the promised cake, her eyes witnessing the harrowing scene. Gil-ryong chases after her as she frantically dials the police, but she flees into the night.
Panicked and on edge, the eyewitness and Gil-ryong abandon their battered conscience and flee with Dong-sik still clinging to life. The eyewitness's anxiety escalates as Gil-ryong, resolute in his quest for the payout, mercylessly suffocates Dong-sik, transforming his unfortunate plight into a case of asphyxiation.
Just as their moral compass spirals further into darkness, Yu-jeong calls the eyewitness, having cunningly spiked Sang-hun's drink to pave the way for extortion. Inspired by a sudden revelation, the eyewitness informs Gil-ryong that he'll manage the disposition of the body alone.
In a convoluted narrative, the eyewitness unfolds his devious Plan B to Yu-jeong. As Plan B swings into action, Yu-jeong rouses Sang-hun from his slumber and subtly diverts his attention during their drive. Reaching the overpass at the opportune moment, the eyewitness heaves Dong-sik's lifeless body onto Sang-hun's car, orchestrating a grim twist in an already twisted tale.
Currently, he unburdens his entire tale to Gil-ryong, who is irritated by the spectacle he has caused. The Eyewitness insists that his intention was to lay Dong-sik to rest properly, but Sang-hun's tantrum derailed his plans. He ponders how they will secure their compensation, while Gil-ryong remains steadfast in his resolve. In the meantime, Officer Baek is located, and through CCTV footage, the police obtain a glimpse of Gil-ryong's face. Chief Park rummages through his possessions and discovers Dong-sik's photograph.
In the parking lot, Jae-yeong amuses himself by rehearsing the manner in which he intends to eliminate Gil-ryong. Upon the ex-convict's arrival, Jae-yeong initiates their journey. Impatient with the delay in receiving their payout, the Eyewitness trails them.
As they approach Guhoe's entrance, the police commence their search for a suspect. Just before Jae-yeong can point out Gil-ryong, he engages in small talk with one of the officers. However, they are actually on the lookout for the Eyewitness, who is wanted for the murders of Sang-hun and Yu-jeong. Realizing this, the Eyewitness bolts, abandoning the vehicle.
Jae-yeong, meanwhile, transports Gil-ryong to an abandoned building. Pretending to retrieve the money, he attacks Gil-ryong with a hammer, as per their plan. However, Gil-ryong had already witnessed Jae-yeong rehearsing his murder in the parking lot. He incapacitates Jae-yeong and confines him within the dilapidated structure.
Gil-ryong divulges their location, prompting the Eyewitness's arrival. The two engage in a heated argument, with the Eyewitness skeptical of their ability to evade the police. Suddenly, he notices his physical resemblance to Jae-yeong. He slays Gil-ryong and exchanges clothing with Jae-yeong, also appropriating his watch.
When Jae-yeong regains consciousness, he commands the Eyewitness to liberate him. The Eyewitness chuckles and declares that he is now Park Jae-yeong. The final scene of Karma Episode 5 reveals the debtor's ID card, affirming his true identity as Jae-yeong.
