Li Wen (played by Zhong Liwen) and Bai Qiao (played by Chen Jianfeng) were assigned to be police officers in Yau Ma Tei after 27 weeks of training in the police academy. Bai Qiao has a steady personality, while Li Wen has a lively nature. The two are partners together, and often have some disputes due to their different ways of handling things. Once when Bai Qiao was on patrol because of his lack of experience, he was teased by a group of bewitched boys and received a complaint. Bai Qiao worried that his future would be affected. During one duty, Bai Qiao witnessed his colleague Ai Lin being beaten to death by a bewitched boy. He was greatly irritated, so he blamed Li Wen, who was handling the case with Ai Lin, and a rift arose between them
After half a year, Bai Qiao, Li Wen and Jing Feng (played by Tao Dayu), who used to be an undercover agent, went to the mobile unit for training. Bai Qiaoliwen fought openly and secretly during the training, which affected the performance of the whole team and caused Jingfeng a lot of headaches. After Jingfeng learned the reason for their estrangement, he came forward to mediate. Later, the three of them participated in the operation of the World Trade Center together. During the operation, everyone cooperated with each other to complete it smoothly. At this time, the two of them understood the preciousness of friendship. The three of Bai Qiao joined the mobile team together, but Bai Qiao was traumatized by Ai Lin's death.