The Worst of Evil

Set in the countryside, Park Jun-mo is a senior patrol police officer who is constantly belittled by his in-laws for having a lower rank and status than his wife. His wife Yoo Eui-jeong, an elite member of the Seoul Security Division, still stands up for him. Fed up with feeling emasculated, he agrees to an undercover assignment in the Gangnam organization to secure a promotion.

Hearing that undercover work could fast track his career, Jun-mo takes the risk and joins the Gangnam organization. The arrangement puts him on a dangerous path inside the criminal network while he balances his duties as a cop and his ambition. The goal is to obtain a promotion that matches his wife's prestige.

Jung Gi-cheul, a nightclub DJ at Gangnam Union, is invited by Jang Kyung-chul to enforce the club and manage unruly patrons. His skill with handling crowds earns him consideration for a higher role. This marks the beginning of his rise within the Gangnam operation.

Gi-cheul's abilities propel him up the ranks until he becomes the manager of the Gangnam Union. With control over the club, he gains power and influence within the organization. The position sets the stage for his later conflict over narcotics.

Faced with wealthy and influential customers, Gi-cheul proposes selling narcotics to boost profits. Jang Kyung-chul rebuffs the idea, fearing it could jeopardize the legitimate business. The rift foreshadows the eventual violence that will reshape Gangnam's power dynamics.

Feeling pushed aside, Gi-cheul and his allies orchestrate an attack that kills Jang Kyung-chul and his followers. During the clashes, Gi-cheul's close friend Kwon Tae-ho is killed. The violence marks a turning point as Gi-cheul positions himself to seize control.

After eliminating Jang's leadership, Gi-cheul meets Song Dong-hyuk, the mob's big boss, to secure blessing for taking over Gangnam territory. He promises Song a monthly profit of 50 million won if allowed. Song considers the proposal and weighs the risks and rewards.

Song accepts Gi-cheul's plan, and Gi-cheul becomes the boss of Gangnam territory and its drug trade. The new order centralizes power and expands the criminal network's reach. Gi-cheul begins to consolidate control over the Gangnam operation.

Meanwhile, Jun-mo's undercover role deepens as he embeds further into the Gangnam organization. He navigates the dangers of double lives, risking exposure to achieve his objective. The lines between his police identity and criminal role blur as the operation proceeds.

The undercover assignment is pursued as a path to promotion that would elevate Jun-mo's status at home and at work. His ambition clashes with the moral and personal risks of his double life.

Under Gi-cheul's leadership, the Gangnam drug trade grows, linking Korea, China, and Japan. The network strengthens as profits mount and rival groups are pressured. Police and competitors begin to sense the expanding operation.

With Gi-cheul now in charge, Gangnam's criminal power structure is reestablished under Song's oversight. The underworld faces a new balance of power and heightened risk of confrontation. Park Jun-mo's undercover mission continues to influence the evolving landscape.