Don't be deceived by the title. Maria's not full of grace... but rubber pellets of uncut heroin she's smuggling into America for Colombian drugs cartels.
Normally these are nameless South American youngsters caught on grainy CCTV in news programmes or documentaries warning of the drugs menace.
Here, first-time director Joshua Marston reaches out to the real victims - women desperate to flee the moribund wreck that is the Colombian economy to start a new life. Anywhere.
Seventeen-year-old Maria (Moreno) supports her family by de-thorning roses from dawn until dusk at the plantation factory which practically employs the whole town.
Oppressed by the mind-numbing nature and over-regimentation of her work, she suddenly quits on the spot after a run-in with a petty supervisor.
Life is further confused by the fact she's discovered she's pregnant... but doesn't want to marry the layabout father because she doesn't love him.
Desperate for a job, she heads to Bogota where a friend works as a maid... but on the way, young hustler Franklin (Jhon Alex Toro) offers employment as a "mule".
Initially reluctant, she eventually agrees after being told she'll be paid around $5,000 for smuggling sixty capsules of heroin into the USA.
Marston expertly handles Maria's elevation from anonymous labourer to high-flying drugs smuggler in a totally non-sensational and measured manner.
It's easy to see how a dirt-poor adolescent could succumb, as the avuncular mastermind gently probes her about her background only to deliver the killer question - "How's your system - is your stomach OK?"
It is only when Maria is aboard a US-bound plane with three other mules that she realises things can go horribly wrong... and they do.
Lean and frills-free storytelling bestow this with a realism absent from other drugs-smuggling movies that revel in the big picture.
This unfolds purely on a personal level thanks to a performance from Moreno displaying the right combination of naivety and bullishness.
It's an all-too believable human story which throws into relief the pitiless evil of the global drugs industry.
Tim Evans