The outlaw Jesse James was murdered in April of 1882 by a treacherous subordinate named Robert Ford. He was shot in the head from behind in the living room of the rented house in St. Joseph, Missouri, where he lived with his wife and two children. (They were in another room at the moment of his impromptu execution.) By the time he was killed, James had been robbing banks, trains and stagecoaches for 16 years, and had a $10,000 reward on his head. He was 34 years old.

These final facts about one of the most heavily romanticized desperadoes of the Old West are by now widely known. Jesse was well on the way into legend in his own lifetime, celebrated in dime novels as a frontier Robin Hood and eagerly promoted, for political purposes, by a Kansas City newspaper editor who sought to portray him as a defiant guerilla in the recently-crushed Confederate cause. James has also been the subject of dozens of movies dating back to the 1920s, the most curious surely being "Jesse James Meets Frankenstein's Daughter," by the awesomely prolific B-movie director William Beaudine. (He also shot a companion cheapie that same year called "Billy the Kid Versus Dracula." But I digress.)

Probably because of the familiarity of the material, there's little attempt on the part of director Andrew Dominik to build suspense into his new movie, "The Assassination of Jesse James by the Coward Robert Ford." Based on a 1983 novel by Ron Hansen, the film leads us through the last year of the outlaw's life to its inevitable conclusion. There can be no real surprises. The movie's brilliance lies elsewhere: in its stirring dramatization of the themes of loyalty, myth and happenstance; in the great Roger Deakins' hauntingly austere cinematography (some scenes look as if they've been lifted off old daguerreotype plates); and in the vivid characterizations of its exceptional cast.

Given the fog of celebrity adulation through which Brad Pitt usually moves, it's easy to forget what a fine actor he is. Here, playing Jesse at the end of his life, sinking into paranoid instability, Pitt anchors the film with muted expertise, conveying James' splintering personality with just an ambiguous stare or a grin of chilling insincerity. Jesse loves his wife and kids, but he scoffs at the hero-mongering press he's been getting — he knows he's no Robin Hood. And very soon — as we watch him beating up a young boy and then shooting an old friend in the back (and then shooting him again while he lies helpless on the ground) — so do we.

Pitt's restraint in the title role serves admirably to clear room for the movie's true star, Casey Affleck, in the role of Robert Ford. To those familiar with Affleck's work only from the "Ocean's" films, his performance here will be a revelation. His portrayal of the timid nonentity Bob Ford, in all his dimness and guile and wounded resentment, is continuously engrossing. After Bob wheedles his way into the James gang on the coattails of his older brother Charley (Sam Rockwell), who's already a member, Jesse treats him as a mildly entertaining distraction from more pressing problems. But Bob is a born annoyance — everyone ridicules him and pushes him around — and after a while, his worshipful gaze and doleful whine begin getting on Jesse's nerves. "You wanna be like me," the older man warily asks, "or you wanna be me?"

Bob would be happy being anybody, but that's not one of the cards life has dealt him. "I been a nobody all my life," he says at one point. "I been the baby, the one everybody made promises to they never kept."

We first see him sniffing around the gang while they lounge in the woods to spring their last big heist, another train robbery. Jesse's brother, Frank James (Sam Shepard), tries to shoo Bob away, but the 19-year-old kid, with his ratty top hat and beseeching grin, is persistent, and soon he's mingling with the other robbers. By this point in Jesse's career, the once-formidable James gang has dwindled into a ragtag collection of low-wattage yokels, among them his irritable cousin, Wood Hite (Jeremy Renner, the life-saving Sergeant Doyle in "28 Weeks Later"), and the ridiculously loquacious Dick Liddil (Paul Schneider). ("I'll just kiss those dainty nubbins," Dick coos as he lifts a wench's hand to his lips.) Even in this pathetic company, though, Bob is still the butt of unending abuse. In desperate search of some sort of appreciation, he finally approaches the police, who are most happy to see him.

After Frank James decides to head east and settle down, Jesse's life is increasingly imperiled — by the law, on one hand, and by bounty-hungry former associates on the other. When his circle of trust becomes so constricted as to include only Bob and Charley Ford, and he invites them to move into his home as resident bodyguards, we know what's coming. What we don't expect is what follows. Having won a grudging renown for shooting Jesse James, Bob takes to the stage to reenact the assassination in a pathetic little show that runs for more than 800 performances, some in New York. He moves to Colorado to open a silver-town saloon, and there meets an end mercilessly similar to the one he'd famously inflicted 10 years earlier.

Apart from the vibrant cast (Schneider and Garret Dillahunt, as a doomed ex-henchman, give breakthrough performances) and the rigorously subdued cinematography (all polished bare-board floors and flat leached landscapes), the movie is also distinguished by the richness of its score, by Nick Cave and his Bad Seeds colleague Warren Ellis, which combines plaintive strings and what sound like wheezing hurdy-gurdy drones into an aural atmosphere of tidal sadness. (The movie's sound design — an enveloping whirl of creaking wood, lonesome winds and dribbling rain — is also something to hear.)

If I were inclined to wheel out clichés like "Oscar-worthy," I'd certainly wheel them out in support of this movie, on several counts. There's Casey Affleck's career-high performance, of course, and Pitt's generous enhancement of it; and there's glimmering support by Mary-Louise Parker (as Jesse's wife), Kailin See (as an old coot's hilariously horny young wife) and Zooey Deschanel (as a good-hearted fan dancer). Maybe most impressively, though, there's the overdue emergence of a really gifted director. This is only the second feature by Dominik, a New Zealander who made his debut with the Australian prison flick "Chopper" seven years ago. What could possibly have delayed his arrival on the international scene for so long? For that matter, why has there been such a delay in releasing this extraordinary movie? ("Jesse James" was supposed to have come out last year.)

No doubt there are predictably dismal answers to both those questions. For now, though, we need only ask whether this picture was worth the wait. I envy anyone the experience of finding out.

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