That’s a good thing, because Dust is based on the novel of the same name by John Fante, and both novel and movie are very much a character study of Arturo, who was, apparently, very much a stand-in for Fante. The misery of being a creative person desperate to make a mark on the world with one’s art, combined with the barely tamped-down panic that one has nothing genuine to offer, is all over the film, and so Robert Towne -- best known for his script for Chinatown, he adapted the novel and directed -- has, at least in that respect, given Fante a worthy little memorial in the film.

But another element of movie magic is missing, and it’s an essential one. Movies can get away with not having among their casts actors as intense and dedicated as Farrell, but they succeed when they generate that ineffable alchemy in which all the elements work together to become greater than the mere sum of their parts, when everything catches fire and blazes to life. That Ask the Dust never catches fire is a mystery, and a tragedy: you sense that it’s on the verge of greatness, and it’s a frustrating exercise trying to figure out why it ultimately fails.

There’s palpable chemistry, for instance, between Farrell and Salma Hayek (Once Upon a Time in Mexico, Spy Kids 3-D: Game Over) as Camilla, the Mexican waitress he can’t help but fall for. Hayek is a firecracker, and Camilla is hot and sweet and sexually dangerous to the inexperienced Arturo. (To think of the, um, storied Farrell convincingly portraying a shy, blustering virgin gives me delicious shivers of appreciation for his talent.) The world in which they live, Los Angeles in the depths of the Great Depression, is rife with bigotry and suspicion of their “kinds,” the “wop” and the “spic,” and how that drives the aversion to each other -- they both have dreams of marrying “real” “Americans” (ie, rich blonds) as a way of elevating their sorry stations -- that overlays their powerful attraction is beautifully portrayed: it comes out in a kind of neo-noir snappishness, a witty, sexy aggression that shows off how formidable Farrell and Hayek are as performers.

There’s Donald Sutherland, turning in perhaps his second best performance ever (after last year’s Pride & Prejudice) as Arturo’s withered neighbor in a shabby Bunker Hill boardinghouse. There’s Idina Menzel as the lonely woman who idealizes the romanticism of Arturo’s work and pursues his affections -- that whole sequence, kudos to Towne, has an air of fantasy about it, as if it were Arturo’s fevered writerly imaginings about women and sex. There’s the stunning re-creation of Bunker Hill, built, apparently, on a high-school soccer field in Cape Town, and the gorgeous muted palette of Caleb Deschanel’s cinematography that evokes sun and dust and heat.

But, alas, all the heat is there in the glare of the Los Angeles sun. There’s no one to blame for how Ask the Dust never becomes greater than the sum of its many great parts. It simply never generates the gravity to ignite.