The political thriller is a fickle mistress. There are few outright misfires in the genre. Yet for every Three Days of the Condor, there seem to be 100 Spy Games; that is, every instant classic yields a gaggle of wanna bes that are decent but don’t quite hit the bull’s-eye.

Focus Films, the art house juggernaut that brought audiences keepers such as Eternal Sunshine of the Spotless Mind and Lost in Translation, this time solicits the genius of Fernando Meirelles, the Oscar-nominated director of City of God (think Boyz n the Hood set in Rio de Janeiro).

Though The Constant Gardener could never hope to be as seminal a masterpiece as the uberviolent and uberbrilliant City, it does introduce English-speaking audiences to one of the world’s visionary directors who no doubt has still got the goods.

We see the world, particularly Africa, in all of its atrocity through the honest eyes of British diplomat Justin Quayle (an ever-sobbing Ralph Fiennes, The English Patient). And if Bono and Live 8 taught us anything, it’s that Africa is home to the kind of cruelty that would even make He-who-must-not-be-named, Fiennes’ next role in November’s Harry Potter installment, suck his thumb in pure terror.

Tessa, a she-who-must-not-be-tamed activist, is played in just the right key of exhausted outrage by Rachel Weisz (Runaway Jury). The pair could not be more opposite (at one point he states, “Diplomats have to go where they are sent,” to which she quips, “So do Labradors.”) and thus they must fall deeply in love.

The opening third of the film takes us along at a rip-roaring pace from the two characters’ love-at-first-fight meeting to Tessa’s gruesome off-camera death-by-ambush.

We are not meant to understand the bevy of characters and plotlines yet, so stop asking your date “Who’s that guy?” and “Why does he want to kill the other guy?”

That’s when Meirelles Tarantinos things, going back in time with Quayle to see exactly why Tessa was martyred while throwing in a bunch of red herring subplots to keep things interesting.

The crux of the story, we find out, is that there will be a Tuberculosis outbreak in a few short years. While most of the world collectively cringes, the drug companies see green, which in turn causes Quayle to see red. The drug company, Dypraxa, gets in bed with corrupt governments to test its vaccine against the new strain on unsuspecting Africans.

Engrossing throughout, Gardener features one of the summer’s most satisfying endings. But it’s Meirelles’ cultural sensibility that really gives this film its flavor.

He depicts a vibrant slum, which is not an oxymoron. Villagers live in tattered homes, but are nonetheless happy to be thriving. They welcome aide workers like Tessa who help but do not pity them. You come away from this film feeling like you’ve learned something, which is rare these days.

Strong supporting performances add a lot to a film that has lots to offer already. There’s no black-hat wrestling villain, but Bill Nighy (Love Actually) lends a sinister sarcasm to the film’s chief G-man baddie and Danny Huston’s (The Aviator) Sandy is a first-class scumbag you’ll love to hate.

Due to its modest star power, this Africa-set flick will probably disappear from the shelves of all but the best-stocked Blockbusters in 10 years. Nonetheless, Bono would be proud.

Contact reporter Patrick Gavin at p.gavin@dbk.umd.edu.