History is at least one of the subjects that Barreto's affecting new film touches upon. Instead of a political thriller soaked with polemic, Barreto looks at the faces behind this turbulent time. In 1969, Brazil was ruled by a brutal military dictatorship. Those who spoke out against the government and its oppression were often held without trial, tortured, executed or just plain "disappeared." Fernando Gabeira and a handful of fellow students recruited into the revolutionary movement known as MR-8 were not your typical card-carrying Communist revolutionaries--they were idealistic young kids whose friends were steadily disappearing around them. Four years previous, these upper-middle-class kids lived in a prosperous democratic society and would have found their kicks drinking on weekends and driving fast cars around Rio de Janeiro's winding hilltops. As fate would have it, though, they found themselves lugging automatic weapons, robbing banks and kidnapping politicians. They didn't set out to change the world--they just wanted a return to normalcy. In 1969, the prevailing attitude was that something had to be done.

Barreto's film concentrates on bespectacled intellectual Fernando (played by newcomer Pedro Cardoso) who joins the loosely organized revolution along with pal Cézar. The two are introduced to the MR-8, one of many small urban guerrilla units springing up throughout Brazil, by the hard-edged Marcão. Also in this tiny cabal are the sad and quiet Renée and the steely leader of the group, Maria (Fernanda Torres). Nervous and less talented at gunplay than his comrades, Fernando finds himself constantly berated and embarrassed by the intractable Maria.

After several successful but perfunctory bank robberies, Fernando decides to assert his skills with the group by planning an audacious and attention-grabbing stunt--the kidnapping of U.S. Ambassador Charles Burke Elbrick (played here, surprisingly, by longtime comic actor Alan Arkin). The kidnapping is successful, and over the course of four days hidden in the country, the ambassador gets to know his kidnappers, the kidnappers get to know each other and the government closes in.

Barreto directs with an amazingly even dramatic hand. He isn't attempting to create a fact-filled documentary here. Four Days in September, like Sidney Lumet's 1975 masterpiece Dog Day Afternoon, wants viewers to concentrate not on events, but on the people swept up in them. Arkin is positively stunning as the calm kidnapee, who shares more than a few philosophical kinships with his revolutionary kidnappers (some say Elbrick's liberal leanings killed his political career in the wake of the kidnapping). In one indelible scene, Elbrick attempts to unravel the personality of his jailers based on their hands (they all wear masks in his presence). Some are scared; some are determined; some (like Fernando) just don't belong in this mess. As clearly and realistically as the ambassador and his kidnappers are portrayed, Barreto manages to expend some compassion even on the brutal government officials who are hunting them down. Henrique (Marco Ricca) is a government torturer assigned to find the MR-8 group. Just like Fernando, though, he is a pawn in a larger game, conflicted and given to self-doubt.