A thriller drama that reveals the realities behind insurance crimes. Mad Dog is a private investigation team that reveals insurance fraud cases. Choi Kang Woo, played by Yoo Ji Tae, was a former detective who now works as a veteran insurance investigator that leads the team. He decides to create his own investigation team after a suspicious airplane crash that took the lives of his wife and son. Kim Min Joon, played by Woo Do Hwan, is a genius former swindler whose brother was also a victim of the airplane crash. Min Joon and Do Hwan join hands and begin their cooperation. Their plan is to disclose the truth behind what happened and to expose those trying to conceal the ugly truth. To today's society where there are not many people left who seek righteousness, Team Mad Dog will demonstrate how things should be done in this era of chaos.