Episode 5 of "Dong Jae, the Good or the Bastard" kicks off with a vivid flashback scene at the bustling bus terminal, capturing Chan-hyeok, Gyeo-re, and Yoo-ri in a fortuitous encounter. As Chan-hyeok steps away to attend a phone call, he inadvertently leaves his cache of purple stash in the toilet stall, a critical oversight. Enter Gyeo-re, who chances upon the stash and eagerly brings it to Yoo-ri's attention. Unaware of its contents, Yoo-ri promptly instructs Gyeo-re to return it. However, Chan-hyeok returns, furious and searching for his missing stash, prompting the students to hastily seek refuge. Their every move is meticulously captured by the CCTV lenses, which Dong-jae and a sharp-eyed police officer scrutinize intently.
While the officer swiftly contacts his team to delve into Chan-hyeok's entanglements within the drug nexus, Dong-jae's mind races to unravel the true perpetrator. Could it be Chan-hyeok, who perhaps resorted to murder by posing as a customer to reclaim his stash and eliminate Yoo-ri? Or might it be Gyeo-re, who harbored desires for the stash himself? Alternatively, was it a grave accident during a moment when Gyeo-re was attempting to tutor Yoo-ri in the handling of a shotgun? Dong-jae zeroes in on the fact that the culprit is undoubtedly a drug dealer, and this opportunist is eager to be recognized for solving not merely a murder but also for dismantling an entire drug cartel.
Elsewhere, Wan-sung's visit to Gyeo-re and his subsequent learning about Gyeo-re's drug dealings from Dong-jae complicate the latter's chances of being released. In a confidential whisper, Gyeo-re reveals to his lawyer that Chan-hyeok had witnessed him peddling drugs.
Concurrently, Dong-jae storms into Mi-ran's office, determined to persuade her to issue an arrest warrant for Chan-hyeok, yearning to spearhead the case alone. However, Byung-gun's timely arrival throws a wrench into Dong-jae's plans, informing Mi-ran about an impending drug sale that promises to catch Geum-ho in the act. Mi-ran reverses her decision, opting to merge both cases due to their interconnected nature. The stage is set for a raid, with the police already having apprehended Chan-hyeok.
As Dong-jae, a notorious scaredy-cat, shrinks from joining the raid, Prosecutor Ji-hee, on her departure, whispers to him that Byung-gun harbors ambitions of ascending to the supreme office by cracking this intricate case. Meanwhile, the police, catching wind of the impending drug cartel raid, spring Chan-hyeok from his duties of keeping Geum-ho chained to the scene, opting instead to shadow him. Wan-sung, desperate to secure Gyeo-re's freedom, storms into Dong-jae's space, but Dong-jae remains indifferent to his pleas. Frustrated, Wan-sung resolves to hunt down Chan-hyeok himself, having witnessed Gyeo-re's illegal dealings. He seeks out Yoo-ri's father, updating him on the drug saga and extracting from him both Chan-hyeok's identity and the locale of his hostess bar.
Elsewhere, as the police swoop in on the drug exchange, Geum-ho, wounded but resourceful, manages to slip through their fingers. Chan-hyeok, curiously absent from the arranged rendezvous, evades the authorities with seamless stealth. Byung-gun, however, is ecstatic, already dreaming of his impending promotion.
Meanwhile, Dong-jae responds to a complaint of gunfire, only to stumble upon a clandestine drug manufacturing hub, with the distributor, Mr. Kang, lying lifeless within. Seizing the moment, Dong-jae devises a plan: if he can crack the purple plant operation, its distribution network, and uncover the producer, he'll leapfrog Byung-gun in the race for the supreme office. Furthermore, he envisions a scenario where Yoo-ri's and Mr. Kang's cases intertwine as a serial killing spree, leading to Gyeo-re's exoneration through unbiased investigation. This would enable Dong-jae to dismantle the treacherous land deal, achieving two victories with a single stroke.
