HUNG TIT leads his colleagues to trash the sign-boards of brothels in Shanghai Street. SUN is in the crowd and he nags at TIT. TIT is angry and argues with SUN. To protect the image of the police force, FAN stops TIT.

FAN`s talent is appreciated by FONG and he is transferred to the special team fighting filthy business. He becomes TIT`s supervisor. In the first task, FAN causes troubles as he is not acquainted with the job. FAN is instructed to investigate whether a dialect club is running filthy business or not. As the club only serves those from Fujian, FAN has to be the spy himself.