Lao Qi (Li Xiaochuan), a foolish fellow in the teahouse, is good friends with Guan Shuai (Li Longjun), who is filming a documentary, and a college student, Zhang Jing (Li Zhengyanqi), who is picking up the story, comes to the teahouse. Zhang Jing falls in love with Guan Shuai, but soon after Guan Shuai leaves, Zhang Jing continues to shoot Lao Qi, who falls in love with Zhang Jing.

Detective Ji Bai and new criminal profiler Xu Xu may seem like an awkward teacher-student pair at first glance, yet they are actually the best partners in the police force, solving one crime after another. Ji Bai slowly falls in love with Xu Xu, yet she is a girl who is as slow as a snail when it comes to love. Just as Xu Xu starts to reciprocate Ji Bai's feelings, the dormant "Angel's Killer" reappears.

Serial killing cases happened in city and the killer disappeared. Campus Goddess, Zhao Ziyu, is always disturbed by a strange dream of childhood. Professor Bai help her with some medicine. Campus Beau, Lin Mu, lost his legs in a traffic accident. His aunt, Jiang Yexin, an expert in Psychology, found Zhao Ziyu to help this boy. Then a big secret of serial killing was discovered step by step...

Mr. Wu, a Hong Kong movie star, is kidnapped in Beijing by Zhang Hua's gang. The police quickly form a task force and begin the search, ignoring that detectives in charge have only twenty hours before the deadline.