Brad Pitt and Julia Roberts are movie stars, so regardless of whether you find their screaming at each other amusing or their characters full of contradictions (he’s a rube sent on a mission by the mob who keeps turning efficient and street-smart, she’s a world-weary hysteric) you should be able to manage, especially if you keep going out for popcorn. For that matter, a seemingly mad dog that periodically turns into a well-trained pet and the title Mexican, an antique pistol that occasionally inspires a heavenly choir, offer even more contradictions and alternate back stories. J.H. Wyman’s plot-heavy and corpse-ridden script gives us a fresh twist every ten minutes or so, on the assumption that we’ll get restless otherwise, the result being that we wind up relatively indifferent to the characters and what happens to them (though James Gandolfini, who isn’t a movie star, manages to be quite touching at times as a gay hood, and Roberts certainly gives it her all, acting up a storm in a vacuum). Directed by Gore Verbinskithe same guy who directed Mouse Hunt, here offering the standard greasy Mexicans favored by Hollywood (who don’t inspire heavenly choirs)with sinister cameos by Bob Balaban and Gene Hackman. 123 min. (JR)