Isabel (Kate Hudson) arrives in Paris to help her older sister, Roxeanne (Naomi Watts), who is pregnant with her second child. She gets there just as Roxeanne's French husband, Charles-Henri (Melvil Poupaud), is leaving her for another woman. Isabel experiences a fast and unsettling introduction to the vast differences between the way the Americans and the French view women, love, divorce, and adultery.
Her culture shock intensifies when she and her sister dine at the luxurious home of Suzanne de Persand (Leslie Caron), Charles-Henri's mother, who has a low opinion of Americans and their habit of giving in to their emotions. She much prefers the French custom of doing things with discreet restraint. So when Isabel begins an affair as the mistress of her brother Edgar (Thierry Lhermitte), a sophisticated and media-wise diplomat with conservative views, Suzanne is the one who is most incensed.
This older married man has a long history of affairs with young women. He wines and dines Isabel and sends her an expensive Hermes bag as a sign of his affection. It turns out this is his trademark behavior, quickly recognized by Olivia Pace (Glenn Close), an American ex-pat and literary figure who has hired Isabel to help her put her papers in order. It turns out she had an affair with Edgar years ago. Equally miffed is her assistant Yves (Romain Duris), who has a crush on Isabel and is upset at being cast aside for such an old man.
When Charles-Henri's lawyers try to negotiate a deal that gives each party in the marriage half of what they own, Roxeanne balks at including a painting of St. Ursula, which she brought to France from Santa Barbara. In a show of solidarity, her father (Sam Waterston), mother (Stockard Channing), and greedy brother (Thomas Lennon) arrive in Paris to make sure that the family heirloom stays in their hands. An art appraiser (Bebe Neuwirth) thinks the painting is an original by Georges De La Tour and so does a representative from Christie's (Stephen Fry). Meanwhile, the angered and insane American husband (Matthew Modine) of Charles-Henri's lover is on the scene making things even more complicated for the distraught Roxeanne. This last element in the storyline is completely unnecessary.
Le Divorce is based on Diane Johnson's clever 1997 novel. It has been adapted for the screen by Ruth Prawer Jhabvala and James Ivory, who also directed, and fits perfectly into this writer and director's series of cross-cultural explorations in Heat and Dust, A Room with a View, and The Golden Bowl. This spritely comedy of manners sparkles with many witty scenes that provide a glimpse into the cultural differences behind the continuing spats between the French and their highly emotional neighbors from across the ocean.