Guan Xiaojing, an 18-year-old high school girl, pretended to be a prostitute in a black organization to carry out fraud. However, she was used by policeman Du Yu to become an undercover agent. At the same time, her boss encountered an accident during an internal fight. As Guan Xiaojing's undercover operation unfolded, the relationship between Du Yu and her became more and more subtle. Guan Xiaojing gradually got closer to the complex truth behind the internal fighting in the black organization, and everything was related to a man named Jiang Beishan of unknown origin...