The film begins with a simple look at the life of Dan and Beth Gallagher, a couple with a young child living in Manhattan. They go to a party and come home to Ellen, their little girl in their bed. We see the portrait of real life in a marriage, and how a man then easily believes he is being put in second place seeks solace in the arms of another woman. Alex becomes this woman who shows her attraction towards him and then speaks overtly about her discretion, alluding to her willingness to participate in an affair if Dan himself is discreet.
The horror that ensues is not solely based on Alex's instability, but on the fact that both she and Dan entered into a relationship that was bound to go nowhere, Dan already having a family. Lyne's film is poignant in the fact that he touches on the small details that are majorly overlooked by married men. One, is Dan's willingness to flirt with Alex at the bar upon meeting her and in the office during a meeting. He leaves just enough of his door open to allow her to believe that he wants her inside. Two, Dan casually dismisses having dinner with Alex as not an issue, that sharing a meal with someone is not wrong. No, it is not wrong, but it becomes the stepping stone for boundaries to be crossed which leads to the conversation between Dan and Alex about discretion. And, that leads to the affair.
What unravels is a tale of a man's pride getting in the way of his ability to see clearly what he has. Dan and Alex sleeping together instantly shows that neither of the two know anything about each other, outside the fact that they are attracted to one another. A fact that leads nine times out of ten to sex and arguments and very rarely to long lasting relationships. Dan's adultery leads to his family's safety being put in jeopardy. He believes that his physically stopping Alex will end what a conversation won't, but it only leads to attempted murder on Alex's part and ultimately to both Beth and Dan killing someone. Though Alex is literally killed in the film, a deeper allusion is that in any affair someone dies whether or not it is seen is another thing. The internal state of a person wilts from the betrayal.
