From its premise alone, “Circo,” Aaron Schock’s documentary about the struggles of a traveling, multi-generation family circus, seems to have “small” written all over it. With all the horror stories you hear about crime, poverty and industrial exploitation in Mexico, a story about one little tight-knit brood, acting out this insufferably cheesy form of entertainment seems doomed to fade fast in the memory. And yet, clocking in at a slender seventy-five minutes, “Circo” achieves an abundance of chilling, unforgettably sad moments—perhaps more than a probing exposé on the current state of rural Mexico would.

Among them: a camel dies, most likely from exhaustion, and is laid to rest unceremoniously in an open field. A pre-teen child, his arms and pecs prematurely ripped, tries in vain to hammer down a tent spike, petrified that his errors will anger his father. In two non-consecutive scenes, a little girl sobs as her elders force her to practice contortionist tricks.

It’s not surprising to discover that preparing for even the most small-scale circus performances involves this degree of torment. What’s more poignant is that there’s no sense of joy or wonder on anyone’s face during the performances themselves. The patriarch and ringmaster, Tino Ponce, wears a stern, hangdog expression through the course of the film, as he leads his large, extended family of performers from dying town to dying town. There’s genuine tragedy conveyed in Tino’s forced enthusiasm when he records circus announcements, in the way he and his teenage children express undying loyalty to the circus that arises not from the thrill of performing but from desperation.

Tino’s father is more or less the film’s villain, barking at overworked, whining grandchildren to practice somersaults. It’s unquestionable that Tino was subjected to the same pressures and ill treatment as a child, and whatever rage he feels has been suppressed into lethargic intonations of loyalty, which have in turn been passed on to his children, nieces and nephews.

“These kids that go to school just play, that’s all they do,” a child around ten years-old dryly observes. Predominantly illiterate, the clan, in a fascinating example of backwards condescension, dismiss more educated or career-driven people as “town folk.” Some of the more spiteful family members have disowned relatives that left the circus to marry such “folk”—and Tino himself feels tension from having married a “town girl,” who spends most of the film scolding him for not finding more profitable work.

The conflict between Tino’s devotion to his wife and family and his adherence to the circus—despite his father’s only allotting three percent of ticket sales to Tino—becomes the emotional core of “Circo,” and it’s at times too shatteringly real to watch. On the one hand, Tino’s wife often comes across as mean-spirited and selfish, looking only at Tino’s impractical, weak side and failing to recognize his overall loving nature and the sense of hard work and togetherness he’s instilled in his children. But at other times, she sounds the wistful note of common sense, as with her immortal statement: “You have children to give them everything, not have them give everything to you.”

That’s about the longest sentence you hear from this taciturn clan. Amazingly, in such a quiet, terse film—with no added narration or coddling of its subjects—Schock captures a marriage in turmoil, a brood torn apart by a wilting, once-adequate family business and the yearning for more mainstream living, the death of a dream. “Circo” is an astonishingly affecting debut feature film.