Chief of the ‘Special Crime Unit’, OH Gu-tak, looks for the former gangster, PARK Woong-chul, whom he had worked with before, and recruits a con artist, KWAK No-soon, and a convicted cop, KO Yoo-sung in the new team. With new blood, the ‘Bad Guys’ have become stronger and tougher. As they dig deeper into the case, they sense that a much bigger crime organization is behind it all and they begin the hunt for bad guys…

Drama series depicts the life of Hong Gil-Dong who is the the first revolutionist and dissident activist in Joseon.

To combat rising violent crimes, the Police Chief asks Detective Oh Goo Tak to form a team consisting of criminals. He is currently suspended from the police force for using excessive force. He then gathers team members: Park Woong Chul who is a gangster, Lee Jung Moon who is the youngest serial killer with extraordinary intelligence and Jung Tae Soo who is a contract killer. Police Inspector Yoo Mi Young also joins the team and she tries to have these guys work as a team by dealing with them rationally and sometimes emotionally.

As a child, Park Hoon and his dad were kidnapped and taken to North Korea. He grew up there, learning to be a doctor just like his father. When Park Hoon escapes back to South Korea and begins work at a prestigious hospital, he makes it his goal to earn enough money to go back to North Korea to rescue his true love. He'll do anything to find her, but then he meets and falls for a mysterious woman who looks exactly like her.

The story takes place in Seoul, 2011. Lee Yoon-sung is a talented MIT-graduate who's working on the international communications team at the Blue House. He encounters dangerous situations while solving a variety of cases, both big and small, for people who need his help, and eventually becomes a "city hunter."