In a deliberately frustrating move for his audience, veteran director Alain Resnais introduces the two main characters of Wild Grass by filming only the backs of their heads.
When eccentric 60-something fox Marguerite (Sabine Azéma) goes to buy shoes, her purse is snatched. Afterward, unpredictable former criminal Georges (André Dussollier) finds Marguerite's wallet and—based on one of the two dissimilar ID photos in the wallet—becomes obsessed with the woman who owns it. He chooses one of the photos over the other as the "true" Marguerite and assigns Marguerite traits, even gives her a backstory.
Georges seems ridiculous for this, but he's doing exactly what we as an audience would have been doing had Resnais not withheld shots of his characters' faces. By introducing Georges' and Marguerite's thoughts (through voiceover), actions and even their mannerisms before showing us their faces, Resnais doesn't give us the chance to do what Georges does. Georges seems irrational for inferring so much from a face, but he is doing what all moviegoers do (or in this case, would have done) when they first see a character in a film.
Marguerite gets her wallet back when Georges hands it over to a police officer (Mathieu Amalric), after which Georges calls her incessantly and writes her a number of letters. But Marguerite tells him to leave her alone. She has her wallet back, she has thanked him and she wants nothing to do with him.
Or does she? The characters' desires in Wild Grass change direction and double back on themselves from scene to scene, even within scenes, often changing multiple times in seconds. Both Marguerite and Georges are literally in dialogue with themselves, talking back and forth in their own heads as if they were possessed of two personalities. This explains why their obsessions and goals fluctuate so wildly, and it helps make Wild Grass a great illustration of the vast, perhaps infinite range of human desire. As we learned from the game with the faces in the beginning of the film, people are not rational.
Even the narrator himself can't always make up his mind: In the first scene, he is unsure what shoe store Marguerite is going to. This is where the film's examination of the complications of desire dovetails with its other primary subject, what it's like to get old. (Georges and Marguerite are both in their 60s; Resnais is in his 80s.) Georges and the narrator experience plenty of so-called senior moments, and Georges' wife (Anne Consigny) is reading Philip Roth's Exit Ghost, in which Roth's longtime protagonist, Nathan Zuckerman, is turning decrepit and impotent. Georges thinks of Marguerite because "thinking of her would be like thinking of nothing." Nothingness is the way Georges thinks of death, so thinking of her is like thinking of death. And here again we have two concerns of the film dovetailing: desire and age; or, more operatically, love and death.
All of these topics and clever cinematic games permeate Wild Grass, and Resnais is giddily unconcerned with resolving any of them. Even as he makes a study of our unpredictable nature as people—obliterating the idea of simplistic character motivation in the process—he also offers a streamlined, captivating plot that brings together not only Georges and Marguerite but Georges' wife and Marguerite's co-worker (Emmanuelle Devos). It would be betraying what works about Resnais' film to pretend to have figured out its meaning or intentions. But it is wholly within the spirit of Wild Grass to be less concerned with meaning than with enjoying, questioning and delighting in this movie's (or any movie's) story, beauty and mischief.