Heroes of the Zeroes is Nick Rogers’ daily, alphabetical look back at the 365 best films of 2000 to 2009.

There are no seasoned pros in the international drug-mule racket. Volatile variables can call up anyone’s number for capture at any time on any trip. There’s even more ruthlessness in the sadistic statistics: Kingpins know one mule will become a sacrificial lamb, distracting officers to let others sail through.

During panic, a contraband convoy can only look to whoever’s calmest at the time. In Joshua Marston’s 2004 Maria Full of Grace, it happened to be the woman with the most to lose.

The only bad thing about Maria’s Spanish subtitles: They diverted attention from the work of Catalina Sandina Moreno — Oscar-nominated for her enthrallingly quick-witted 2004 performance as a teenager in over her head.

Maria is smart, stubborn and eager for a challenge. Pride, culture and tradition obstruct her, but so do poor choices, such as a pregnancy with a go-nowhere boy in her Colombian village. Swallowing dope and smuggling it to the States is an alluring one-time proposition to bankroll her baby and future, but risky rebellion leads to major responsibility and a looming threat of cartel violence.

Pellets are eventually expelled, but Marston’s closed-throat suspense never relents, as Maria’s reliance on the kindness of strangers and her ability to sell lies test her shaky survival instinct.

Maria’s subject matter could be, and has been, exploitative in other projects, but Marston shrewdly sketches asides of social drama about whether Maria should imply remain in New York. To his credit, the outcome of that choice feels as fraught with peril as Maria’s drug-running.