Westerns lend themselves to moral philosophy because they are set in a fabulous past, when life was simpler, as crime stories tend toward melodrama because they unfold in a mythical place, where passions are grander. The entertaining Appaloosa combines both genres, not surprising for a film based on a rare cowboy novel by crime writer Robert B. Parker. And what are detectives but lawmen in three-piece suits, which the film’s marshals, Virgil Cole (Ed Harris) and Everett Hitch (Viggo Mortensen), prefer to chaps and dusters. And what are outlaws but gangsters robbing stagecoaches, the guilty pastime of not-so-gentleman rancher Randall Bragg (Jeremy Irons) and his posse of petty crooks and thieves.

Harris, directing his second feature (Pollock was his first) from a script he wrote with fellow actor Robert Knott (also second-unit director), doesn’t overdo the good-versus-evil bits, keeping the ethics decidedly situational. Cole and Hitch may call themselves peacemakers, but itinerant gunslingers would be a more accurate job description: They make it their business, literally, to tame the West. The aldermen of Appaloosa (Timothy Spall, James Gammon, Tom Bower) have hired the duo to rid their fledging community (a saloon and sheriff’s office connected by dusty boardwalk) of the noisome Bragg, who has made himself generally unpleasant, as well as shot the former marshal and his deputies in cold blood.

Cole and Hitch, professional tough guys who have handcuffed more ornery critters, have no trouble bringing in Bragg for trial, but they start acting like giddy schoolboys around the town’s new arrival, the provocatively named, and coyly seductive, Allison French (Renée Zellweger). As we have come to expect, women mean trouble, no matter how many petticoats they wear, and Allison brings it in aces and eights. The twist to Appaloosa is that our fair-haired heroine turns out to be the most conniving, and complicated, character in a film that remains, at heart, a shoot-’em-up. Allison is a woman who does what needs to be done to protect her investment in herself: We haven’t seen her like on-screen since those scandalous pre-Code dames defied Prohibition in their flimsywear.

That said, Appaloosa remains a man’s movie, a story of loyalty, courage and, despite the muddied morals of its characters, justice. Harris and Mortensen, sporting a handsome vandyke, fit the archetype—strong and silent with ice water in their veins, except for a pool of sanguine affection they reserve for one another. The actors make the most of a routine that pokes gentle fun at Cole’s dyslexia, a kind of mental stutter that exasperates Bragg, whom Irons plays with effete sardonicism just shy of parody.

Harris handles the film’s several subplots, the sum of which make the whole, with considerable skill, although audiences must be prepared to suspend disbelief more than a few times: Like westerns of old, bandits and Indians appear conveniently as the plot requires. Why were all of Bragg’s men up and about on horseback at the crack of dawn, but not in position to protect their boss while enjoying his morning constitutional in the outhouse? Such implausibilities aren’t worth pondering too closely. Appaloosa is true matinee material, sumptuously photographed, captivatingly acted...but with this cast, we would expect nothing less.