Shanghai in the 1930s. Qin Xiao Man (Una You) is a beautiful young woman who just graduated from the police academy and dreams of becoming an outstanding detective. She moves into the Sullivan appartment complex in the International Settlement and solves one case after another. Her neighbor is the famous master sleuth Luo Fei (Bai Yu) who works as adviser for the Criminal Investigation Division of the police department. Due to their completely different personalities, the two don’t get along at first, but have to join hands in the end in order to solve a bizzare case.