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.

Master and apprentice begin in their hot-blooded journey to fighting crime when the cold lone ranger meets the "little fresh meat." 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 has the heart to do good yet things do not always work out. He 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.