Bachelors that they are, they explore different types of women. They meet Catherine, a vibrant, excitingly different kind of girl. She's fun, and fun to be around. All three of them seem to be dear friends. Catherine pursues a relationship with Jules, and they fast become lovers. At this time both Jules, and Jim are called off to war. Fearing that one of them might kill the other, because of them being on opposite sides of the conflict. They both survive and remain friends, along with Catherine.
Catherine and Jules marry and move off to the country, and have a little girl. Jim however stays in the city and has a serious relationship Gilberte. All seems well to Jim, but is unaware of the problems that Catherine and Jules are having.
Jim visits with them in the country, he finds out that Catherine has been having affairs, and Jules is unsure how to keep her happy. He tolerates the infidelity because he can't live without her. Catherine confesses to Jim that she has feelings for him. Jim goes to Jules to talk to him, and Jules tells him that he wants her to be happy, and to still be in his life no matter what. Even if it's with him. All three live together in a bizarre love triangle. Catherine and Jim try to have a child together, but are unsuccessful. Jim has to go back to the city to do business. While he's there he reconnects with Gilberte. Writing back and forth, Catherine senses that Jim has cheated on her, and as her revenge she cheats on him.
When Jim returns he tells Catherine that he is going back to Gilberte. She freaks out at him and pulls a gun on him. He leaves, and Jules and Catherine resume there affair.
Jim runs into Jules, and Catherine an they all three decide to have lunch together. Catherine drives and shows off her new car. After eating lunch she tells Jim that she wants to show him something, and tells Jules to watch. She drive them both off a broken bridge on purpose, killing both of them. Jules is left with his two best friends ashes to dispose of, but is some how relieved that he is free of Catherines hold, and the torment of her being with other men.
Taking a character like Catherine and making her so likable, and then making her so despicable. She seemed to want to have all the men around her adore her, and want her and when Jim didn't see her in the same light anymore. Catherine took the "If I can't have him, then no one can" attitude. I didn't know if I wanted to feel bad for Jules, or look down upon him for being so spineless. Jim seemed to have fallen for Catherine's trap, but when he realized that he was just in awe of Catherine and not in love with her, he left (unfortunately he returned).
The film itself kept at a good pace, and used some symbolism throughout. A tremendous amount of thought was put into the little things that were shot, and contributed to the feel of love between the three of them.