Like so many foreign-language Oscar winners before it, South Africa's ''Tsotsi" presents a harsh, gritty surface beneath which swims an ocean of sentiment. It's a solid, earnest drama of moral redemption that places old cliches in an unfamiliar setting, and if director Gavin Hood's insistence on our common humanity is both rousing and necessary, he's still dealing from a dramatically stacked deck.
Tsotsi is Soweto slang for ''thug" and the name of the initially anonymous young street criminal (Presley Chweneyagae) at the film's center. He's the most feral of his small pack of hoods; when the gang silently robs and murders a man on a crowded Johannesburg subway train in the movie's opening minutes -- a shocking if not quite believable sequence -- not only is Tsotsi unbothered by stirrings of guilt, he brutally beats a gang member (Mothusi Magano) who feels they've gone too far.
Or is his vicious reaction a manifestation of long-dormant conscience? A few scenes later, Tsotsi steals a car from an upper-class black woman and leaves his victim screaming in anguish in her driveway. For good reason: Her infant son is still strapped in the back seat. Rather than finding a way to return the child or disposing of him in ways not fit to contemplate, Tsotsi takes him home to his shanty, cradling the baby in secret like a foundling puppy.
In the days that follow, as the hero struggles to hide his new charge from prying neighbors, the police, and his hard-case friends, Tsotsi's granite exterior begins to crack. Memories of his own childhood seep in -- both the domestic trauma he ran from as a boy and the unforgiving homeless existence to which he fled. Desperate to feed the child, he barges into the home of a nursing mother named Miriam (Terry Pheto) and forces her to breast-feed the kidnapped infant at gunpoint. Out of this gruesomely one-sided arrangement rises the first chance at human connection Tsotsi has known.
''Tsotsi" is based on the only novel written by the South African playwright Athol Fugard (''Master Harold and the Boys"); belatedly published in 1980, it was written around 1960 as a cry of outrage over the spiritual costs of apartheid. The book's antihero was the hellish byproduct of a hellish system; the movie's Tsotsi, living in a vastly changed South Africa, is both more complicated and more simplistic.
The story's subjects are now the tribal infighting, intransigent poverty, and black-on-black crime that continue to plague the country's lower classes. To avoid criticizing one ethnic group at the expense of others, Hood has his thugs speak in the Soweto street slang known as ''tsotsi-taal" (imagine the nadsat of ''A Clockwork Orange" repurposed for the African ghetto). A white Afrikaner police detective (Ian Roberts) is one of the more sympathetic figures in the film; the fact that the carjacking victims are a bourgeois black couple -- the fact that such a couple even exists in South Africa -- indicates how dramatically the social landscape has changed.
Does this tale have resonance anymore? As a spiky, tough character study with a core of feel-good humanism, yes. Chweneyagae, an acting newcomer, never flinches even when his character finally does; it's an impressively still performance that suggests volcanic emotions roiling beneath. ''Tsotsi" never erupts in fully convincing ways, though, and a young writer's plot contrivances can be glimpsed through the fabric of the film's modern setting. That baby cries only when dramatically necessary, and he's awfully accepting about being toted around in a paper bag for much of the running time.
As you might expect, the soundtrack is luscious, particularly the contributions of Zola, the reigning star of post-apartheid hip-hop pop known as kwaito. Lance Gewer's burnished, brooding cinematography turns the skies over Soweto the color of an unhealed bruise. There's nothing really wrong with ''Tsotsi" except its predictability, and one only begrudges its Oscar when one considers the richer, deeper films (''Caché," ''2046," ''Head-On," ''Nobody Knows") that weren't even in the running.
Ty Burr can be reached at email@example.com.