Trini’s daughter is sad that her best friend is leaving Saint Michael School since her mother can’t keep paying for it. Trini promises her daughter that this won’t happen and decides to put together a plan with the other “mamis” of the group to solve the problem. But this mission will be much more difficult than they thought and they will have to stick together as a group.

Santiago, capital of Chile during the Marxist government of elected, highly controversial president Salvador Allende. Father McEnroe supports his leftist views by introducing a program at the prestigious “collegio” (Catholic prep school) St. Patrick to allow free admission of some proletarian kids. One of them is Pedro Machuca, slum-raised son of the cleaning lady in Gonzalo Infante’s liberal-bourgeois home. Yet the new classmates become buddies, paradoxically protesting together as Gonzalo gets adopted by Pedro’s slum family and gang. But the adults spoil that too, not in the least when general Pinochet’s coup ousts Allende, and supporters such as McEnroe.