Gan Tianlei, Xiong Guoliang and Yang Xiaolei used to be the Three Musketeers of the police academy. However, Gan Tianlei was dismissed after he wounded someone in order to help Yang Xiaolei. After leaving the academy, he was recruited by Caesar Group and started working undercover. During a mission, Gan Tianlei gets caught in an explosion and falls into a coma. Eight years later, Gan Tianlei awakes in the hospital but loses all his memories. Finally, all criminals from two major gangs—Caesar and Tan’s—were arrested by the police....

Due to the needs of the task, three young martial arts school students- Xin Xiaojing, who is good at fighting, Cheng Tang, who is smart, and Bai Daqing, who loves parkour, are liked by Captain Zhang Lan and get recruited into the police force. Three of them sneak into the criminal's lair and carry out secret arrest. All team members have withstood all kinds of tests from the outside and the inside, and become excellent policemen....