Mean Streets: GAVIN HOOD'S 'TSOTSI'.

Tsotsi, the latest winner of the foreign-language-film Oscar (the language being a Sowe-to street argot called Tsot-si-taal, which means roughly Thug Talk), proves how gripping a stale story can be when it's filmed with realism and elan.

Adapted and directed by Gavin Hood from a novella by Athol Fugard, this South African tale has so many Hollywood ancestors that we may think of it as belonging to genre called Gangster's Guide to the Moral Galaxy. The pattern: sinners discover that they have a heart and a conscience when they ... find a helpless baby (John Ford's Three Godfathers) ... rescue a child marked for death by the Mob (John Cassavetes's Gloria) ... encounter a family cheated by evil relatives (My Three Angels) ... find themselves mistaken for monks or priests (Brother Orchid). Accidentally coming into contact with innocence, the bad guy discovers he loves innocence and wants to regain his own.

Three Godfathers may be the classic in this genre and Tsotsi is its direct descendent, for it's about a young Johannesburg gangster who discovers a baby in the back seat of a vehicle he's just carjacked. For a few seconds he considers abandoning the infant but then takes responsibility for him, carrying him around in a shopping bag, forcing a nursing mother to breastfeed him, agonizing over whether to return the baby or not, and how to do so. Flashbacks explain why this seemingly affectless hood shows such concern, and the main action of the script demonstrates the consequences of his caregiving. Does our hero find redemption? Silly question! What would be the point of a story about a bad guy and a baby if redemption were not in the offing? In fact, Tsotsi is an art-house crowd pleaser for precisely the same reason that Three Godfathers was a mass-market hit. Bang bang. Goo goo. Irresistible.

Yet Tsotsi is not (or, at least, mostly not) hokum. Why? First, Gavin Hood's depiction of the township of Soweto has horrifying immediacy. Poverty, sundrenched squalor, hordes of unwanted children being taught by violence to perpetrate violence, the inanition bred by joblessness and the social alienation bred by official brutality (in one scene, a suspect cornered by police automatically expects to be executed)--all this is presented with the same sizzling realism that we encountered in the much greater movie that inspired Hood, Fernando Meirelles's City of God. While that Brazilian masterpiece took off into all sorts of unexpected directions, letting its narrative be shaped by the desires and machinations of its wayward protagonists, Tsotsi uses its realism strictly to freshen familiar plot mechanics. It gives us just enough understanding of how the outer civic chaos creates the moral chaos within our hero.

Second, though Hood reveals in flashbacks of the unhappy childhood that turns an abused child named David into the adolescent gangster Tsotsi (just a nickname meaning "thug"), he doesn't make the mistake of unveiling the past too completely or too soon. Only when a crisis jolts Tsotsi's mind back to the past are we jolted back with him. As in some of the best movies of the sixties--Petulia or La Guerre est Finie--each flashback is a jigsaw puzzle piece, and only when enough of them fall into place can we see the entire picture. Even then there is no startling revelation: that a gangster with a lost childhood might identify with a baby separated from its mother is hardly a novel notion, but at least Hood doesn't pretend that Tsotsi's memories explain absolutely everything about him. Rather, the very fact that Tsotsi is having a flashback because he's come under stress is more significant than the flashback itself.

Third, and most important: Presley Chweneyagae is the lead. In casting this relatively inexperienced actor, Hood struck two veins of gold--the right physique backed up by a strong talent. Even before his acting takes hold of us, Chweneyagae's face convinces us in a most unsettling way that we are looking at a hatred that has frozen the hater into a permanent and hideous childhood that substitutes for a normal, well-nurtured childhood. Chweneyagae gives us a Peter Pan of evil, whose Neverland is sealed off at the border by switchblades and handguns. Yet behind the actor's face is a much larger aptness: a talent (fortified by a surprisingly rich voice) that knows when to boil and when to freeze. What this novice thespian knows about Tsotsi pinpoints and enlarges what Hood put into his script: just because a hoodlum does one good deed doesn't mean that he ceases to be a hoodlum. At one point, Tsotsi shoots a psycho about to murder a robbery victim. Then we see Tsotsi's next thought flit across Chweneyagae's face: the killer I just shot was my brother in crime, so I owe it to him to kill the man he wanted to kill. It is the actor's ability to convey Tsotsi's emotional volatility and moral vagueness that keeps the character fascinating even in the toils of a narrative that is basically predictable. Both Gavin Hood and Presley Chweneyagae know that it's a long return trip from Tsotsi to David.