The political map of the taut, suspenseful Brazilian documentary Bus 174 is laid out in an aerial shot that floats over the wealthy side of Rio de Janeiro's mountain topography and then down into the thickets of the city's notorious slums. To understand the geography, suggests filmmaker José Padilha, is, perhaps, to understand how a stupid, small bus hijacking in June of 2000 unraveled, in the course of a bungled standoff, into a stupid, awful tragedy.
While the showdown between Sandro do Nascimento and the police went on for four hours, Brazilian TV covered the events in agonizing real time. (Officials couldn't keep the media from talking to the hijacker.) Padilha makes precise use of copious news footage, and then alters the tense rhythm of inevitability by inserting interviews with participants and commentators including a cop, a social worker, and former hostages. Although it shares a bitter interest in slum desperation with last year's Brazilian-underbelly docudrama ''City of God,'' ''Bus 174'' pulls ahead, I think, by not confusing cinematic pizzazz with the content of misery.