For pudgy, pink-faced Gonzalo Infante, another 11-year-old, the universe ruptures twice in a matter of months, once to tantalizingly admit people from the poor side of town, and another time to harshly push them back to the margins. Santiago in 1973 was the site of a peaceful revolution and a violent counterrevolution, the latter of which the Machuca protagonist watches with confused helplessness, much the way he observes his imperious (and married) mother’s afternoon trysts with a wealthy Argentinian. Privileged yet naive, Gonzalo (Matias Quer) has yet to be initiated into the real workings of the Chilean ruling class when he encounters aristocratic power at its most savage.

Like Innocent Voices, which opened here last month, Machuca attempts to muffle any potential backlash by taking a boy’s-eye view of American-backed state terrorism. That strategy renders both films a little softer than their subjects seem to require, but it is justified by their autobiographical origins: Innocent Voices was based on the brutal childhood of its scripter in ’80s El Salvador, and Machuca is derived from the childhood memories of its director and co-writer, Andrés Wood. As his surname suggests, Wood was a member of an Anglo component of Santiago’s gentry, much like his fictional counterpart. Though Gonzalo doesn’t have a British name, the archetypal poor little rich boy does attend an English-language prep school whose uniforms and curriculum suggest the fantasy of a below-the-Equator Eton.

There’s a radical element, however, among the Catholic priests who run the school. One day, the headmaster brings some new boys into class and announces that the student body will now include these poor kids from a nearby shantytown. The shabbily dressed contingent includes Pedro Machuca (Ariel Mateluna), who becomes lonely Gonzalo’s best friend, as well as his ally against the inevitably blond schoolyard bully. Gonzalo begins spending time with Pedro’s family—which includes beguiling older sister Silvana (Manuela Martelli)—joining his new pals in selling cigarettes and flags to demonstrators on both sides of the country’s political divide. (Silvana makes it clear, however, that she prefers the leftists.) To Gonzalo, this street theater is great fun, but his parents and their peers are not amused, and they stage a counterattack that starts with a tumultuous PTA meeting and concludes with the overthrow of the new leftist president, Salvador Allende.

Much of Wood’s tale explores routine coming-of-age stuff—first drink, first kiss, first awareness of the class divide—while keeping the country’s growing desperation in the background. Then the coup occurs, and the film’s backbone stiffens. The racism that underlies much Latin American fratricide, insinuated gently by Gonzalo and Pedro’s shared passion for comics starring the Lone Ranger and his faithful Indian sidekick, becomes fiercely tangible when troops invade the Machuca family’s slum—and Gonzalo is once again reduced to the role of powerless observer. The movie’s last 10 minutes are suitably harrowing, and Gonzalo’s final words sharply illuminate his plight. If portions of Machuca are bland and schematic, its coda unflinchingly dismisses the notion that an 11-year-old can redeem the world his or her elders have made.