Every once in a while a film comes along that reassures you about the importance of independent films. Joshua Marston's "Maria Full of Grace," the story of a 'mule' for a drug cartel, is the kind of film that would never survive a studio script conference, and yet it is so finely made, and speaks so strongly to the rightness of the individual vision, that it makes more of an impact than any dozen studio action films.

Marston, an American filmmaker who works in Colombia, tells us the story of Maria (Catalina Sandino Moreno), a seventeen-year-old worker in a small town whose job is to strip thorns from long-stem roses before they're shipped to the United States. She's bored with her job, angry with her boss and her boyfriend, and feisty when it comes to being badly treated by either of them. When she finds she's pregnant she decides to go to Bogota to look for a job. She meets Lucy (Giulied Lopez), who's already done two trips as a mule, and decides to take the chance herself, which involves swallowing dozens of small packets of cocaine, getting on the plane to New York and not expelling them until she's in the hands of her drug contacts there. The images of her learning how to swallow them, practicing first on large grapes, and then dealing with the little bags themselves, are riveting beyond belief.

Unexpectedly Maria's best friend Blanca decides to be a mule as well. She doesn't quite have Maria's smarts, and so we start anticipating the likely problems she might cause. Marston takes his time, trusting in us to know that he won't settle for anything less than the real thing, and letting his story unfold at the pace of life rather than forcing it through contrived confrontations. So we are with her as she comes to comprehend what it is to be a mule - namely that she is something like a shipboard container for an exporter, carrying the goods but nothing more unless something goes wrong. And if she should arrive in New York with the merchandise intact, there is still a great deal for her to go through.