Xu Wu Shuang, a detective in his thirties, heads up the criminal division of the Suicheng police department. He is extremely rational and would strike without hesitation once he has his sights set on a target. Meanwhile, rookie cop Wang Dai Yu goes by the book too much and has a much soft personality. Being a fuerdai, he could have inherited his family's riches yet chose to be a public servant.A rookie cop has gone undercover without the knowledge of the deputy captain of the police. They are pushed into opposite camps due to misunderstanding, thus marking the start to a cat-and-mouse game.