Architect Terry Lambert (Steve Guttenberg) takes pity on Sylvia Wentworth (Isabelle Huppert)|the apparently put-upon wife of his brutish boss (Paul Shenar). Terry commences an affair with Sylvia and during a break between seductions|Sylvia hears a woman screaming from outside her bedroom window. She looks down to see a mysterious man strangling helpless victim Denise (Elizabeth McGovern). By the time Terry comes to the window|he can see only a crowd of spectators. The next day|Terry learns that another girl has been attacked and murdered|and begins to deduce that the killer may be the same person who assaulted Denise. He wants to go to the police|but Sylvia refuses to get involved. Or is she already involved?