Sunghoon and Niki are both of the same agency and they have to go undercover to do some mission. At first, Sunghoon knows that he's working alone on this, but Niki soon makes his presence known. (Sunghoon, the top agent, undercover as a detective. Niki, the best agent, undercover as a criminal)

Sunghoon, the agency’s most decorated agent, is assigned to infiltrate a criminal organization suspected of orchestrating a high-stakes diamond heist. He's confident in his ability to handle the mission alone—until he encounters the agency's rising star, Niki, already undercover as one of the gang's most trusted members. Forced to work together under false identities, their rivalry intensifies as secrets are revealed, trust is tested, and lines between duty and personal feelings blur.

As Sunghoon entered the dock, the smell of grease and rust filling the room, he was surprised to find Niki there instead. But he tried to keep his calm, as he couldn't blow his cover. As Niki saw Sunghoon, a smirk spread over his face.

"Ugh, this is ridiculous." Sunghoon thought.