This drama is about the battle between detectives who try to reveal the truth and those who frequently cover it up. Set in Incheon, South Korea, detectives try to catch criminals, who hide ugly truths. Kang Do Chang (Son Hyun Joo) has worked as a detective for the past 18 years. He was born and raised in Incheon. He investigates cases using his experience and personal connections, forgoing scientific technique or reasoning power. Meanwhile, Oh Ji Hyuk (Jang Seung Jo) is an elite detective. He has 9 years of experience. Unlike Kang Do Chang, he investigates cases using evidence and insight into the criminal’s psyche. Due to trauma from his childhood, he does not share his feelings. He is wealthy thanks to his late uncle, who left him with a large inheritance. Jin Seo Kyung (Lee Elliya) works as a newspaper reporter. She is a 5 year veteran and passionate about her work.