Detective Park Sang-yoon couldn’t shake the unease gnawing at him over the Youngin murders. The hospital’s director and his wife were found dead in their home on different days, and their daughter, prodigy Choi Ro-hee, had seemingly been kidnapped by a disheveled man caught on surveillance. At first glance, it was a straightforward ransom plot: poor Kim Myung-joon snatches Ro-hee, kills her parents, and vanishes.

But something about the murders and the family’s inner circle didn’t add up. Ignoring his supervisor’s orders to focus solely on finding Ro-hee, Park dove back into the case—only to be suspended. Undeterred, behind the police's back, he teamed up with both Myung-joon and the girl to untangle the truth. When his superiors learned about his unlawful actions, they had him arrested. Now, handcuffed in a Seoul precinct with Detective Jang watching him smugly.

JANG: "You know what separates a detective from a suspect, Park? Paperwork. Chain of command. Following it."

PARK: "Thought it was evidence."

JANG: "Evidence says you obstructed an active kidnapping and murder investigation, collaborated with the perp, and removed sealed files from Yongin Regional without authorization. That’s before we get to you playing hero in the press. Internal Affairs loves heroes. They will finally mount your badge."