Policewoman An Nan (Sandra Ng) is clumsy and accidentally kills her father Feng Sir when arresting drug lord Chen Liang. An Nan has been practicing hard since then, hoping to avenge her father. An Nan uses Ah Zhen (Annie Pak), the mistress of drug dealer Fei Qi (Cheng Kui-an) as an informant, from whom she gets the news that Fei Qi will trade with Chen Liang. An Nan volunteers to participate in the arrest, but is suppressed by her boss Lao Hu Gou (Chen Wei) who is seeking revenge. An Nan takes the initiative to take action, but Chen Liang escapes again. An Nan is worried about the safety of Ah Zhen, and takes care of her with her colleague Li Chen (Lin Xiaolou). After Ah Zhen, who is addicted to drugs, pleads repeatedly to snatch drugs for her. That night, Fei Qi finds Ah Zhen and beats her up, and has people surround An Nan and Li Chen. As a result, Li Chen dies, and An Nan is framed by Lao Hu Gou after escaping. With nowhere else to go, Anan escapes from the police station and goes to look for Fei Qi's younger brother Xiaoxian (played by Stephen Chow). This is her last chance to avenge her previous humiliation...