Starring Ed Harris, Viggo Mortensen, and Renée Zellweger. Rated PG.

Despite some anachronistic dialogue and odd hints of lethargy, the handsome Appaloosa is an honest ode to the old-fashioned Western that doesn't kill itself updating the formula of man, horse, and gun. It's really about two men, plus their horses and guns.

The alpha hombre here, in the Arizona of 1882, is one Virgil Cole, an impeccable paladin embodied by Ed Harris, who also directed and cowrote the terse script from Robert B. Parker's novel. Virgil's trusted sidekick, Hitch (an almost unrecognizable Viggo Mortensen), carries a massive shotgun, giving him the name Eight Gauge.

This pair roams from town to town, generally hired by the right side of the law to help stamp out somebody worse, and they are sufficiently self-aware to acknowledge that their ruthlessness pretty much wipes out any claim to virtue. When complex thought is needed, Hitch is required to help articulate what's going on. They get along that way.

Loyalty is put to the test in the dusty town of the title, currently plagued by a suavely vicious varmint called Bragg (Jeremy Irons). Breaking up Bragg's gang is only half the battle; the aging lads are further challenged by the arrival of Mrs. French (Renée Zellweger), a comely easterner with good manners, some talent at the piano, and no Mr. French in tow.

Hitch prefers the company of a clear-eyed saloon gal played by Spain's great Ariadna Gil, and, frankly, so do we, although both women's parts are severely underwritten. For some reason not explained by the Code of the West, Virgil's steel is dangerously softened by Mrs. French, despite her inclination toward whoever appears to be top gun of the moment. It's this feeling of fluid ambiguity, not the unswerving attractions of genre, that makes Appaloosa a keeper.