From its ads, director Emilio Aragon's adventure drama A Night in Old Mexico seems limp and unpromising -- it looks like one of those limited-release efforts financed solely on the basis of casting, and that have a way of cropping up, dying, and fading into the woodwork (per Looking for Palladin or Bloodworth). This may happen to Mexico -- it is getting issued to only a handful of theaters, and all bets are off on how many people will actually see it -- but the film is undeserving of that obscurity. It isn't any sort of masterpiece -- the final act in particular feels like one long mistake -- but it has a surprising number of good things in it that make it worth seeing, and foremost among them is a robust, scene-chewing performance by that all-American perennial, Robert Duvall. Duvall stars as Red Bovie, an 83-year-old Texas rancher facing bankruptcy and foreclosure. On the day when he's slated to be shipped off to a retirement community, he loads a handgun and puts it to his temple, changes his mind at the last minute, and then discovers that his estranged grandson Gally (Jeremy Irvine) has turned up to express an interest in working on the property. Meanwhile, a nearby drug deal leads to violence and bloodshed, and sends two psychopaths on the lam with 150,000 dollars. That afternoon, Red and Gally prepare for the move to the senior center, but Red suddenly guns the accelerator of his car and takes off. The pair head down to Mexico for a last-ditch thrill ride, and along the way, cross paths with the two thugs, who end up hitching a ride with them. The premise of an old blowhard fantasizing about life as a tough hombre and getting to live that out is a familiar one, albeit entirely welcome. There are traces of Louis Malle and John Guare's Atlantic City, as well as Duvall's characterization in Assassination Tango -- though the tone here isn't as twee as the former or as manically eccentric as the latter. In Night, the conceit works. One of the movie's sly pleasures is the willingness of the script (by Lonesome Dove scribe William D. Wittliff) to conscientiously dodge clichés time and again. For instance: During Red's suicide scene -- where he desperately prays to God out loud and tries to make a deal for a second chance -- it would have been so facile for Gally to burst in as a magical "answer" to Red's prayers. But this doesn't happen. And it would have been equally predictable and lackluster for the presence of the two psychopaths to put Red and Gally's lives in immediate danger. But this also doesn't happen as we expect it to -- not exactly. Nor does the female presence of the story (Angie Cepeda as Latina stripper Patty Wafers) strike up an expected love affair with Gally; the screenplay is too smart for that. This sort of unpredictability gives the first hour or so of the movie a refreshingly off-center quality, and redirects the focus of the screenplay from a violent, formulaic crime thriller with an erotic edge to a study of the shifting relationships of the central characters. The film's thematic focus involves Red's tortured family history. Outwardly, he's a tough, foul, and ornery old buzzard, a man who resists any emotional connection. (When Gally declares, "I'm your grandson," his only response is to curse.) Gally, too, is basically a lonely character, whose appearance at Red's farm betrays a desperate need for family. One of the main transitions of the drama, then, involves the two men's capacity to gradually drop their impenetrable armor and forge a bond that reaches across the generational gap. This builds to an inspired scene of mutual recriminations, in which underlying motivations emerge with great, naked force. That depth is what gives the movie resonance, and lifts it out of the realm of predictability and to the level of something more special. At that point, the crime elements of the story become totally superfluous; it would have made more sense for Wittliff and Aragon to drop the violence and thuggery and end the story on a more peaceful note between Red, Gally, and Patty. Unfortunately, they do not -- perhaps due to commercial considerations -- and as such, the last act is a 20-minute misstep. The ending is filled with silly chase scenes and shootouts that not only stretch the movie's credibility to the breaking point, but carry it far afield of its actual purpose. And Gally's final responses to Red aren't simply illogical, but cut against the entire grain of his arc. Still, as mentioned, Duvall's work is really something to behold; it's a courageous, unrestrained evocation, and the Oscar winner is clearly having a ball with this role. Wittliff not only gave the iconic performer a dynamic character to work with, but supplied Red with an acid mouth and crackling, wiseass dialogue that provides numerous belly laughs, as when the old cowboy confronts a heavyset Mexican gangster with a barrage of petulant insults and acrimonious potshots. (When the hood asks him, "Which river do you want to cross?" he shoots back with, "The River Nile, you ignorant son of a bitch!") Duvall gives this picture lift and buoyancy, and helps it transcend its weaknesses; watching him do his thing onscreen makes one deliriously happy.