Set in the tense atmosphere of the 1980s, this series follows a married couple who both work as detectives and share a strong commitment to fighting crime. When authorities discover the existence of a powerful criminal syndicate controlling a vast drug trafficking network across East Asia, the couple is assigned a highly dangerous undercover mission. Their task is to secretly infiltrate the organization and gather evidence that could finally bring down the people responsible for the illegal trade. As they step deeper into the world of organized crime, the detectives must carefully build trust with members of the syndicate while hiding their true identities. The organization operates across several countries, including Korea, China, and Japan, making the investigation even more complex and risky. Every move they make must be calculated, because one mistake could expose their secret and put their lives in immediate danger. While carrying out this mission, the couple faces enormous pressure both professionally and personally. Maintaining their cover requires them to live double lives and constantly face situations filled with suspicion and violence. As the investigation intensifies, they must rely on each other more than ever, balancing their roles as partners in both marriage and law enforcement while trying to dismantle a powerful criminal empire.