Advertising director Charles Schine (Clive Owen) is just another Chicago commuter, regularly catching the 8.43 to work. But the day he misses his train is the day that changes his life. He meets Lucinda Harris (Jennifer Aniston), charming, beautiful and a seductively good listener. Charles is instantly attracted and it is immediately apparent that the feeling is mutual, even though she is married too. Lunch dates become cocktails after work, and lead to a rented room in a seedy hotel. But suddenly their illicit liaison turns into a nightmare, and becomes more dangerous and more brutally violent than either could have imagined. Unable to talk to his partner or to the police, Charles finds himself trapped in a world he doesn't recognise, and which he needs to fight his way out of, before his life is derailed for good...