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....