Pil-seong is an idle detective who spends his days scratching off lottery tickets in his office, while his wife and children run a small manhwa shop. In a moment of weakness, he secretly borrows ₩300,000 from his wife's emergency stash to bet on a bull named Gomi, hoping for a quick win. The bull proves victorious, and Pil-seong’s friends celebrate later that night as they wait for him to arrive.
The revelry is interrupted when an escaped prisoner, Song Gi-tae, barges into the scene and steals the money Pil-seong had quietly planned to keep. When Pil-seong learns what’s happened, he confronts the thief, only to endure a humiliating defeat that leaves him staring at a lineup of skeptical colleagues who don’t believe his story.
Determined to prove himself, Pil-seong pieces together a plan with the help of friends who already faced Gi-tae in trouble. He aims to trap Gi-tae inside a house where Gi-tae’s girlfriend, Kyeong-joo, is kept nearby, and he sneaks in armed with pepper spray while his friends wait outside the windows. Gi-tae, however, anticipated the move and slips away just before the police arrive. Before leaving, Gi-tae wounds Pil-seong’s right hand with a knife and warns him that the next attempt to capture him will be fatal.
Humiliated publicly and pushed away by his wife for the money troubles, Pil-seong channels his pain into training. He takes taekwondo lessons and learns that the upper rib cage is a vulnerable target—hard knowledge that he quickly turns into a personal defense. He even buys a handgun for his own protection.
In the next confrontation, Pil-seong corners Gi-tae by surrounding him and taking Kyeong-joo hostage to force a moving target pursuit. His friends intervene, allowing Gi-tae to escape again, and they urge Pil-seong to quit, but he refuses to walk away from the fight.
One of Gi-tae’s allies, Pyo Jae-seok, is arrested by Pil-seong. Pil-seong confiscates Jae-seok’s phone and commands him to bring back the stolen money. Gi-tae hides somewhere in a fishing village, and Pil-seong uses a bullhorn to force him to reveal himself.
Gi-tae calls from a distance, letting Pil-seong know he’s near the family’s manhwa shop and gives him one hour to deliver the money, or Gi-tae will destroy the shop with the family inside. Pil-seong complies, but he also orchestrates a police presence at the shop. He buries the money in a small fenced area and then, in a tense moment, shoots Gi-tae in the stomach but chooses to discard the handgun and use Gi-tae’s own knife to demand a fair fight.
What follows is a brutal, measured exchange as both men exchange blows and punishments, each refusing to back down. Gi-tae corners Pil-seong, demands the money, and retrieves it before walking away. Pil-seong musters his strength, along with a precise upper-rib cage strike, and manages to subdue Gi-tae, though he remains weak and nearly unconscious from the exertion. His colleagues later discover him in a cell, asleep with Gi-tae handcuffed at his side.
In the days that follow, Pil-seong and his team are rewarded with promotions as officers. They march in a ceremonial parade to his daughter’s school, and the film closes with Pil-seong and his fellow officers saluting the crowd in a moment that marks a hard-won victory and a new chapter in his career.
