In the distance, sandstone cliffs, as imposing as the outcroppings in a John Ford Western, loom over the unruly bacchanal—and over Luis and Esteban’s urgent search—with monumental indifference. By the time “Sirāt” ends, roughly two hours later, that sense of godlike impassivity has practically seeped into your marrow. We are still in the Sahara, although it’s not clear where. The characters, or the ones that remain, are bound for parts unknown, and any inclination toward revelry has vanished from their weather-beaten faces. But Laxe’s film—which won a Jury Prize at Cannes this year, and which Spain has submitted for the Oscar for Best International Feature—isn’t a cynical or nihilistic work. The movie begins in exhilaration and concludes in despair, and what unfolds in between is an experience of singularly turbulent and transfixing power; for sheer visceral excitement and sustained emotional force, I haven’t encountered its equal this year. It’s an extraordinarily propulsive piece of filmmaking, and every moment of it is suffused with feeling. For all its perils and cruelties, “Sirāt” doesn’t drain you or numb you into submission. I left it unsteady but invigorated, and grateful anew for the ground beneath my feet.