Han Lingfeng, a top bodyguard, is assigned by the villain Cao Zi'ang to protect Su Nuo, the only witness to a shooting. On the surface, Han Lingfeng is there to protect Su Nuo, but in reality, he is an undercover agent sent by Cao Zi'ang to monitor her. Neither Han Lingfeng nor Su Nuo knows that the mastermind behind the shooting is Cao Zi'ang himself. During the process of protecting Su Nuo, Han Lingfeng accidentally uncovers a larger conspiracy. In the end, Han Lingfeng successfully helps Su Nuo escape the pursuit and brings Cao Zi'ang to justice.