The film Perfect Stranger opens with reporter Rowena Price (Halle Berry) and researcher Miles (Giovanni Ribisi) going after a conservative senator who has been having sexual encounters with his male interns. However, the story is shut down when the source suspiciously clams up. Disgusted, Rowena quits her job. While walking home, she meets her childhood friend, Grace (Nicki Aycox), who seeks her help in taking down Harrison Hill (Bruce Willis), a wealthy businessman. Grace gives her emails as proof of their extramarital affair, which he recently ended. A few days later, Grace is found dead, leading Rowena to suspect Harrison. With Miles's help, Rowena goes undercover as a temp at his company. She flirts with Harrison both online and in real life, but he catches her snooping and fires her, believing her to be a corporate spy. At Miles's apartment, Rowena discovers a shrine of herself and explicit pictures of Miles and Grace. He arrives home and they fall out. She goes to the police, who arrest Harrison for the murder of Grace.

After his conviction, Miles visits Rowena, explaining that he knows she is the real killer and has been using this investigation to frame Harrison. He wonders what Grace had on her. Rowena flashes back to a memory of her father trying to molest her and being accidentally killed by her mother. They buried his body in the backyard as Grace watched from a window. In the present, Miles asks how she intends to keep him quiet, implying she might return his feelings at last. Instead, she stabs him. She ransacks the kitchen and calls the police, claiming to have been attacked. The film ends with a man looking out a neighboring window, presumably having witnessed what really happened.

Halle Berry - Rowena Price
Bruce Willis - Harrison Hill
Giovanni Ribisi - Miles Haley
Jason Antoon - Bill Patel
Jane Bradbury - Toni
Jared Burke - Keneth Phelps
Gary Dourdan - Cameron
Tamara Feldman - Bethany
Deirdre Lorenz - Veronica
Nicki Aycox - Grace
Paula Miranda - Mia Hill
Lauren Potter - Client #1