Roy Chen Chih-Lai is a sick rapist/serial killer with a leg fetish and cuts off his victims' legs as trophies after he's through with them. One day at a bank robbery shootout he catches police woman Cheng Hsuen on camera and chooses her to be his next victim. He begins to stalk her and enter her personal life even waiting for her inside her home. He notices her sister Kelly as well (who is also a cop) and her boyfriend Ken. After he kidnaps and rapes Kelly Cheng decides to lure the madman by using herself as bait and bring justice to the situation.