Iris looks in the mirror every night to voice her frustrations, as if telling a close friend or family member her grievances, but something strange begins to happen. Iris discovers that someone is quietly solving her problems at work, which earns her praise from her coworkers and superiors, but this mysterious person is gradually invading her life—and her love life—forcing her to seek out the truth.

Roy Chen Chih Lai is a serial rapist and murderer 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.