"Appaloosa" is one of those movies that creeps up on you after the fact. It's not a blood-and-thunder Western, although there are some tense standoffs and shocking explosions of violence. It moseys sometimes when you want it to gallop. It's a character study with six-guns, and as you peel away its layers, recalling a telling gesture here, an unstressed moment there, and some of the clever surprises it has hidden away in its saddlebags, your admiration grows in retrospect. Directed and co-written by Ed Harris ("Pollock"), it's a horse opera for grown-ups.

Harris stars as Virgil Cole, a hired gun who rides with Everett Hitch (Viggo Mortensen). They are hard, rigid men who sign on to clean up lawless frontier towns such as Appaloosa, a rawboned Arizona community whose civic founders are too soft and timid to protect their own. The wolf at their door is black-hat landowner Randall Bragg (Jeremy Irons), who shoots lawmen as casually as if he were shooing horseflies off his shoulder. He's a feudal lord holding out against the tide of order and progress.

The story plays out as the collision of this irresistible force against two immovable objects. It takes its time, though. Harris encourages us to put our feet up and savor the small incidents that establish a person's temperament. Virgil and Everett aren't much for talking, so their relationship unfolds through sly shared jokes and silent glances. Virgil is flinty and reserved, but volcanic passions boil beneath his surface. He's apt to beat a man senseless for a minor discourtesy; Everett is the only person who can restrain him. When Virgil gropes for a word, Everett is his encyclopedia.

Their partnership is tested when Allie French (Renée Zellweger) steps off the train, turning Virgil's head with her feminine allure. Virgil, whose encounters with women have been rough and ready, is instantly infatuated with this refined creature. She bathes every day, he tells Everett, amazed.

Allie plays more than the typical woman's supporting role in the story, revealing unexpected traits that won't be revealed here. Suffice it to say that her emotional drives are more Darwinian than feminist, and that her presence complicates the power dynamics in Appaloosa in fascinating ways. She could be a symbol of encroaching civilization, the coming of a time when subterfuge and calculation replace the politics of fists and guns. And that new set of rules puts steadfast Virgil and Everett at a handicap against the Braggs of the world, who evolve to take advantage of changing circumstances. They're living at the end of an epoch when shootouts settle scores, and entering an era of legalisms and influence peddling.

There are moments when "Appaloosa" feels more like a tribute to a beloved genre than a fresh story that demands to be told, yet there's much to admire. Harris is fine as a tough man softening under the influence of unfamiliar emotions. When he smiles, it's as if he's trying out a set of muscles he's hardly used before, and when jealousy overtakes him, his inner turmoil is vivid. Mortensen looks like he stepped out of a daguerreotype, and even his gestures have an antique quality. Zellweger deploys her dimply charm to sweeten a character who is at heart utterly self-serving. Irons struggles with a false-sounding accent, but he's otherwise formidable enough to stand against his costars. Even the throwaway parts are carefully cast. English actor Timothy Spall ("Harry Potter") plays one of Appaloosa's craven city fathers with jowl-wobbling, fussy theatricality, and B-movie heel Lance Henriksen makes a long-overdue comeback in a villainous role that once would have gone to Lee Van Cleef.

Harris doesn't have the gusto for action that energized Sergio Leone or Sam Peckinpah, but they're done making movies and he isn't and a wise man is grateful for what he's got.

Colin Covert • 612-673-7186