In her small Parisian apartment, Laure (Valerie Lemercier) is just finishing packing all of her possessions. The next day she will move in with her lover. The anxiety that accompanies this transition point in her life is steep and rising. As she puts some stuff in the hall, some neighbors gladly cart it away. Laure takes a bath and heads down to the street and her car. She is set to have dinner with some friends. But that plan is put into jeopardy due to a monumental traffic jam that has brought the whole city of Paris to a near standstill. To the left and to the right of her are other drivers trying to restrain their anger and frustration at this inconvenience caused by a public transportation strike. Laure tries to pass the time with music and then sorting through some books in a box in the back seat of the car. A fellow reads the sign on her window about selling the automobile and asks her how much she wants for it. When he finds out, he laughs in derision.

An announcer on the radio makes a plea for drivers to be charitable in these dire circumstances. Laure offers a ride to a pedestrian who says he doesn't need a lift. Then she spots Jean (Vincent Lindon) who seems to be unperturbed by all the congestion on the streets. She offers him a ride and he gets into the car. When asked where he wants to get off, he responds "leave me where you want." He smokes a cigarette and for a brief period of time they both doze off in the stalled car. Suddenly his calm seems to vanish and he takes the wheel, pulling out of the traffic jam and speeding down side streets. She orders him to stop, and he gets out. She follows him into a store where he is buying condoms. Realizing that he's ready for sex, she kisses him. Their sexual embrace is an antidote to all the pressure, anger, and confusion of the traffic jam.

The novelist John Fowles has written: "Sex is an exchange of pleasures, of needs; love is giving without return." Writer and director Claire Denis (Beau Travail, Chocolat) brings these two strangers together in the midst of an urban crisis. His ardor and knowingness is what she desires on the last evening before moving into a serious commitment with her lover. Denis convincingly makes the alluring city of Paris at night into a vivid character in the drama. In Friday Night, the usual fear of the stranger is turned around into something completely different.