Between 2007 and 2010, Nicolás Pereda wrote and directed four features (all being screened this week, with the director in attendance). Often, that’s the schedule of an artist on a hobbyhorse—or else a factory line. But the 27-year-old Mexican has taken this relentless work ethic and pushed it to an abstractly exhilarating new place. Pereda’s movies aren’t just linked by their narrative concern with Mexico’s contemporary poor; most of them also star a mother/son dyad played by actors Teresa Sánchez and Gabino Rodríguez. And in every single film except Where Are Their Stories? (8 p.m. Thurs.), their characters bear the actors’ real-life first names. Yet the works don’t serve as sequels or prequels to one another. If these characters are always engaged in acts of subsistence-maintenance, they are still easily differentiated. Soldier-boy Gabino, from the docu-hybrid Summer of Goliath, is a sadistic prick compared to the sweet kid in Juntos (8 p.m. Mon.) who just wants to find his dog and cool down the scalding-hot water coming out of his tap. You can’t help but see the populist impulse in Pereda’s work, but he shuns uncomplicated sentimentality. The range of his characters— cheats, pranksters, layabouts, and honest hardworking types—makes it clear that Pereda really wants to investigate the margins he can’t stop filming.