Probably the least useful thing to know in advance about Gus Van Sant’s Gerry is that it stars, and was written by, Matt Damon and Casey Affleck. This knowledge can only work against the film, less by raising hopes for a kind of entertainment that Gerry is uninterested in offering (to say the least) than by tempting the cynical to dismiss this elegant meditation as a rich kids’ art project. The ideal viewer of Gerry is someone who doesn’t even know who Damon and Affleck are (not having seen Van Sant’s three previous movies, Good Will Hunting, Psycho, and Finding Forrester, would also help). That person is free to enter, without preconceptions, the disturbing world of the film.

The two characters in Gerry, who are both named Gerry, go hiking toward some destination identified only (with the whimsical obscurity that characterizes all their dialogue) as "the thing." They impulsively discontinue the trip and turn back, only to get lost. Trying to return to the highway that brought them, they go deeper and deeper into the desert.

From its first shots of a car driving on a desert highway, Gerry establishes its slowness, its fascination with bodies, its involvement with the time of things happening. Van Sant lets shots run on long after they seem to have made their point, making us aware (as in many films that use extreme shot duration, like those of Andy Warhol, Michael Snow, Chantal Akerman, and more recently Béla Tarr and Aleksandr Sokurov) that the running-on is the point. We can either walk out or let the movie happen at its own pace. And if we let it happen, then it can work — for me, Gerry does — by focusing our attention on its choices of composition, camera movement, and cutting, getting us involved in its own decisions about what kind of film it’s going to be.

Although to watch Gerry, it’s necessary to be interested in this process (not so much in the technical process of filmmaking as in ways of thinking through, and with, film), the movie also works on other levels. It’s de rigueur in survival films for characters to bicker, come to blows, blame each other for their predicament, reveal their long-hidden mutual hatreds, and so on (the Dogme 95 travesty The King Is Alive encapsulates all these options). Gerry avoids these clichés. Throughout almost the whole of their ordeal, the two characters, who are so comfortable together that they’ve apparently developed their own language, treat each other with respect. They may or may not be lovers; the subject never comes up, and the way the narrative unfolds makes knowing unnecessary. The unclouded manner in which the film portrays male friendship is rare in movies and deserves admiration.

Gerry also revives the American cinema’s landscape-art tradition, which has been largely neglected in narrative movies since the commercial decline of the Western. The film’s willingness to pay attention to landscape, to let it create a mood, is extraordinary. So is the scale of some of the images, such as an extreme long shot in which the two men, standing on different hills and talking to each other across a ravine, are just dots on the screen. Dread and awe offset the movie’s flatness. Clouds hurtle through the sky; the wind, sharp and dry, is an assaultive force (on the soundtrack above all). In one shot, tumbleweeds fly into view from behind the camera, as if hurled after the two men as they walk away.

The dialogue is the most problematic aspect of Gerry, since it’s here that the film must either try to work as a psychological drama or justify its not working as such, and either choice has pitfalls: on the one hand, triteness and conformism; on the other, a cute and self-conscious quest for avant-garde cachet. Van Sant, Damon, and Affleck largely avoid both traps. The enigmas at first seem forced (why can’t the characters’ initial destination be named?), but they become more alluring as the characters take off on inspired riffs (Affleck’s "I conquered Thebes" routine is extraordinary) and deploy their mysterious jargon and funny variations on American vernacular.

I kept doubting Gerry, but I also kept liking it, not just for its formal rigor but for its compassion and for the surprising risks it takes. And unlike most films, it gets better as it goes on. The most convincing proof that Gerry is an excellent film lies in its last two shots.