Grade: B-

At one point in Ed Harris’ adaptation of Robert B. Parker’s western novel, Virgil Cole (Harris), the hard-nosed marshal of the titular New Mexico town in the 1880s, takes his lady friend Allison (Renee Zellweger) for a carriage ride and, having a love of the words he encounters in Emerson and like writers, explains to his deputy Everett Hitch (Viggo Mortensen) that they’re going perambulating. It’s a perfect word for “Appaloosa,” too, because the movie meanders, moseying along in long, discursive dialogue sequences between occasional eruptions of action (mostly gunfighting), inserting often lovely but digressive visuals and frequently overlooking transitions that would be deemed obligatory in a more conventional film. (At one point, for example, our two heroes appear to be mortally wounded. In the next scene they’re sitting at a dinner table, barely scathed.)

The plot, such as it is, is one of the oldest in the genre: Cole and Hitch are hired to defend the town against the ravages of nasty bad-guy Randall Bragg (Jeremy Irons), who has a ranch nearby and a bunch of hard-case men in his employ. Exactly what his plans might be isn’t made clear, but since he’s summarily killed the previous marshal and his two deputies, he’s obviously up to no good. (The fact that he claims acquaintance with President Chester Arthur is apparently a sign of ill repute, too.) Finding a witness to Bragg’s crime in youngster Joe Whitfield (Gabriel Marantz), who’s willing to testify, the men arrest Bragg and must keep him safely in jail until the circuit judge arrives—though he men aim to spring him.

But as if those tropes weren’t enough, the script also introduces a woman—the aforesaid Allison French—to whom the stern but gentlemanly Cole is attracted. Her arrival not only sets off an odd triangle with the two unofficial lawmen but complicates the plot involving Bragg in ways that won’t be revealed here but lead to an even stranger triangle and an act of self-sacrifice to address it.

What’s nice about “Appaloosa” is that it takes the old western conventions and juggles them in very odd but mostly satisfying ways. But what makes it really special is the characterization it draws of Cole and Hitch and its depiction of their friendship. Both are portrayed as men who live by a code—one that can surely be harsh and violent, but is also honorable and principled in a very personal sense. And their relationship has an aura of knightly camaraderie about it. Cole is a demanding fellow whose quirks Hitch caters to, but in a fashion that upholds his own craggy dignity. And Cole depends utterly on Hitch, not only for the words that sometimes just won’t come to him but for back-up whenever it’s required. And when one of them must put everything on the line for the other, he won’t hesitate. Harris and Mortensen play the parts without exaggeration, but with a wonderfully understated sense of humor; the two worked together previously in “A History of Violence,” and clearly enjoy each other’s company. Watching their interplay here is like seeing a great dance routine performed by consummate pros.

The rest of the cast bring their best work to the party, too. Zellweger carries off the schoolmarmish business—though the lessons she teaches aren’t ordinary ones—and Irons underplays the villain, which makes him all the more effective. Among the others, Timothy Spall stands out as the goofiest of the town fathers (though Tom Bower and James Gammon aren’t far behind), Lance Henriksen makes a splendidly oily gunman, and Bob Harris is properly cantankerous as the judge. Marantz has some nice moments as the nervous trail hand with a conscience, as does Ariadna Gil as Hitch’s saloon squeeze.

Where “Appaloosa” doesn’t quite measure up—apart from the rather shambling structure, which doesn’t match the amusing repartee—is on the visual side. Dean Semler’s cinematography isn’t up to his usual standard; the compositions aren’t as elegant as you’d expect, and there’s a ragged quality to many of them, particularly in the opening reels. Kathryn Himoff’s languid editing accentuates the problem, and Jeff Beal’s score apes the majestic tones of a Goldsmith or a Bernstein, but with a tinny orchestration that makes it sound almost like a parody.

Despite the occasional flaw, though, “Appaloosa” is an engaging entry in the still modest but happily growing western revival. It’s no classic, but the pairing of Harris and Mortensen makes it rather special nonetheless.