Episode 12 of "Good Boy" unfolds with an uncommon sight—Jae-hong, a figure previously absent from the season's most buzzworthy scenes, finally stepping into the limelight during his discus event. Yet, unlike his peers, triumph eludes him. Fortunately, Dong-ju arrives to offer solace, silently holding an umbrella against the relentless rain, his mere presence a gesture of empathy and support amidst Jae-hong's bitter defeat.
This poignant moment of failure segues us back to the present, where Ju-yeong's determination to secure revenge burns brightly. He reaches out to Dong-ju, offering an apology tinged with acknowledgment of his prior underestimation, but also fanning the embers of their rivalry anew. Conscious of his return to scraps and underhand tactics, Ju-yeong embraces the primal thrill of dirtying his hands once more, reminiscent of his ruthless handling of a smuggler from his past. Recall the fake watch he bestowed upon Ju-yeong? Its revelation as a counterfeit sparked a violent confrontation, with Ju-yeong emerging victorious, the genuine timepiece now in his possession.
This sets the stage for an impending clash, as news of the 26 tons of cash seized by Man-sik and his team from the containers dominates headlines. The President's office calls, but Man-sik and his allies play tough, recalling the police's unhelpful stance. Rumor has it they intend to bring Golden Bunny to the Supreme Prosecutors' Office to testify, a move advantageous to them, as it prevents Insung from manipulating the case. Celebratory spirits lead the group to Jae-hong's place.
Ju-yeong and his cohorts react starkly differently to the news about Golden Bunny. Dissension and doubt creep in. Yeon-ha, who had tirelessly crafted Candy for him, stands on the brink of abandoning him. Her frustration peaks when he threatens her sister, prompting her to slap him across the face in a stark display of her resolve.
While Jae-hong secures approval for his loan, Dong-ju's fortunes take a turn for the worse. He faints at the gym and brushes off Han-na's inquiries about his health with a fabrication, claiming the mysterious stains on his shirt are merely kimchi brine. Their contemplation is cut short, however, as Man-sik orchestrates the group's relocation to the Pawnshop. They are resolved to construct a compelling case against Ju-yeong, amassing evidence and seizing every opportunity while he's on the ropes.
Empowered by the loan approval, Jae-hong takes a paid leave of absence to lend his hand to the investigation, joining forces with the team. Yet, their focus is abruptly diverted by reports of tainted drugs circulating in Insung—a clear scheme orchestrated by Yeon-ha and Ju-yeong. Dong-ju catches a glimpse of the Drug Demon, shuffling unsteadily away from the epicenter of the crisis, only for her to crumple to the ground, her blood sugar plummeting due to her diabetes. As before, she's apprehended and handcuffed, with Dong-ju's assistance in stabilizing her condition. Yet again, she manages to slip away from custody.
Subsequently, Jae-hong and Dong-ju are dispatched to the Myeongjin Shopping District, where the drugs have been making their rounds. As they roam the area, Jae-hong receives a devastating message—his loan has been rescinded due to "unforeseen circumstances," orchestrated by Jong-gu, who demands further documentation.
As Jae-hong grapples with his own set of challenges, Dong-ju finds himself under siege by a brutal gang of thugs. But this encounter proves far more daunting due to his precarious health status. His attempts at retaliation are feeble, and he gravely underestimates Jong-gu, whose powerful right hook leaves little to the imagination. Jong-gu strikes with precision, mocking Dong-ju as "punch drunk" and reducing him to mere ridicule before carting him away. The news of Dong-ju's plight strikes our group like a bolt of lightning, leaving them stunned and horrified.
Dong-ju is subsequently dumped inside a shipping container, a grim tableau of blood and despair, in front of Ju-yeong. Realizing Dong-ju's fragile health, our antagonist cruelly injects him with a lethal dose, condemning him to a slow and painful death. Yet, in a twist of fate, Yeon-ha, whom Dong-ju once saved, steps in to repay the debt. She urges him to cling to life for just ten minutes, and as the container begins to move, she sneaks him the antidote, reversing the drug's deadly effects.
Through Yeon-ha's bravery and treachery—switching sides to aid Dong-ju—he manages to wriggle free and flee for his life. Even the ruthless "Drug Demon" draws the line at harming children. But Insung is no ordinary town; Ju-yeong's minions are relentless. Dong-ju is savagely stabbed in the abdomen, and the media paints him as a dangerous fugitive, further complicating his plight.
Ironically, this turns out to be a blessing in disguise, as it alerts the group to Dong-ju's whereabouts. They scramble to reach him before Insung's corrupt law enforcement does. Dong-ju, now heading towards Eungcheon-dong, converges with Man-sik's path. The stakes have never been higher, and the race against time begins.
Regrettably, the situation takes a dramatic downturn when Ju-yeong places an exorbitant bounty on Dong-ju's head. With the law enforcement hot on his trail, Dong-ju now finds himself hunted illegally by every gangster within the vicinity, the noose tightening inexorably around his neck. It is Jong-hyeon who manages to track him down first, only to discover Dong-ju in a precarious state, bleeding profusely and battling for his life. Yeon-ha arrives shortly thereafter, lending her aid to stabilize him and urging Jong-hyeon to rush him to the hospital for detoxification.
Man-sik proposes a detour to Seongjin City, citing Insung's scorching heat as too perilous for them at present. Mr. Baek nearly secures their escape route when Leo arrives to visit Sergei, who is currently in the company of Gwang-se. Tragically, Sergei's fate takes a grim turn here, leaving us uncertain whether our Bald Eagle has survived this ordeal.
Jong-hyeon finds himself in a precarious position too, after his car is involved in a T-bone collision. Desperate, he reluctantly reaches out to his brother for assistance, even offering to relinquish his shares in exchange for this favor. Jong-hyeon's brother eventually agrees, and Dong-ju is rushed to a doctor. While undergoing treatment, the group arrives to lend their support. This conflict is far from resolution, but Han-na is determined to expedite matters. She gathers her belongings and heads to Insung, ready to confront Ju-yeong head-on.
