Frannie Avery (MEG RYAN) is creative writing teacher who's fascinated by everyday words, sayings and phrases, so much so that she seems to have forsaken romance in her life. Perhaps that's also due to her former boyfriend, John Graham (KEVIN BACON), being so obsessed with her every move that he's practically stalking her.
Her world changes when she's out with one of her students, Cornelius Webb (SHARRIEFF PUGH), who's writing a paper arguing the innocence of serial killer John Wayne Gracy. While looking for the bathroom, she sees a woman performing a sexual act on a man whose only distinguishing mark is a tattoo on his wrist. Not long afterwards, that woman is found brutally murdered.
Homicide detectives Giovanni Malloy (MARK RUFFALO) and Richie Rodriguez (NICK DAMICI) arrive on the scene and ask Frannie what she might know about the crime. Although she's unable to provide any information, Frannie is inexplicably drawn to Malloy, a point that her half-sister, Pauline (JENNIFER JASON LEIGH), says she should act upon.
Frannie does, and soon the two begin a torrid love affair. Yet, as more murders occur and the investigation continues, various developments and behaviors soon have Frannie wondering if someone she knows - even Malloy - might be the actual killer.