To combat rising violent crimes, the Police Chief asks Detective Oh Goo-Tak to form a team consisting of criminals. Detective Oh Goo-Tak is currently suspended from the police force for using excessive force. Detective Oh Goo-Tak gathers team members: Park Woong-Cheol 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. Also, Police Inspector Yoo Mi-Young joins the team.
The prisoners have escaped! A prison convoy turns over and the worst criminals escape. The police call the 'special crime investigation department' once more. It is a highly classified project in which jailed criminals catch felons. Release the 'Mad Dog' once again! Captain Oh Goo-tak (Kim Sang-joong) pays former co-worker and legendary fist Park Woong-cheol (Ma Dong-seok) a visit and recruits scammer Kwak No-soon (Kim Ah-joong) and former detective Go Yoo-seong (Jang Ki-yong). The new team is stronger and much worse than before. The more they uncover the case, the more of a strong feeling they get that a huge criminal organization is behind it, and start moving in on them... These bad guys don't move by the law! They think and act like the bad guys!