If only they had packed a compass

"Gerry" isn't the most tantalizing title of the season, but the movie itself is one of a kind. It reconfirms Gus Van Sant as one of today's most original filmmakers, and Matt Damon as a star who's not afraid to take box-office risks.

Mr. Damon and Casey Affleck play two young men whose names we never learn.

This isn't because the screenplay is being coy, but because they're the only characters, and most of their dialogue is devoted to matters of life and death, not conversational chitchat.

They've driven far from civilization for a day of hiking in an unidentified wilderness of craggy hills and desert wastes. A few hours later, they realize they're lost.

What they do is what any semiskilled backpacker would do - scramble up rocks to get a wider view, try to figure out which direction is which, trudge across desolate stretches in search of a house, a highway, anything. It's impossible to predict whether they'll make it home or perish. The movie's title is their colloquial term for an awful mess, which is exactly what they're in.

Many audience members may feel they're in one, too. "Gerry" is an uncompromising picture - a radical experiment in stripping a story to its bare essentials, then pushing those essentials as far as they'll go, asking spectators to be as intrepid and tenacious as the characters.

I found it an invigorating journey, less like viewing a typical film than taking in a silent movie or (at times) a series of barely-moving photographs. My preview companion left after 15 minutes to read in the lobby. We both had a nice evening.

Made with a minimal script, "Gerry" was largely improvised on location, and as sheer craft it's a striking achievement. Among his inspirations, Mr. Van Sant has mentioned directors Béla Tarr and Chantal Akerman, two great innovators in the treatment of cinematic time. "Gerry" doesn't reach their lofty artistic level, but it shares their audacious spirit more than any other recent American film.

Van Sant's experiments don't always work - his "Psycho" remake is one of the most pointless pictures of all time - but they're usually more interesting than mainstream films like "Finding Forrester," where he obeys the commercial rules.

Take a chance on "Gerry." It's only a movie, and you'll get out alive no matter what happens on the screen. You might even find you've had a rare adventure.

• Rated R; vulgar language and scenes of physical duress.