Larry Clark's photographs and films dwell on the twilight of adolescence and the dawning of adulthood, often featuring violent collisions between seductive, impersonal cultural forces and the young lives of his subjects that they threaten to uproot. The setting here is Marfa, Texas (pop. 2,000), a border town whose vast desert skies have inspired generations of wandering artists and whose Border Patrol keeps an oppressively close watch over Adam (Adam Mediano), a half-white half-Hispanic teenager, and his single mother, a collector of birds. Sex, drugs, and music are the sacraments in the rites of passage that Adam and his friends experience; but their youth, beauty, and shared intimacy provoke the sadistic and voyeuristic urges of Tom (Jeremy St. James), a federal agent devoid of moral compunction or personal ties. The strength of Clark’s cinema is in its documentary veracity. Marfa Girl’s best moments lie somewhere between action and dialogue, where Clark’s framing and his talent for capturing the geography of faces and bodies reveal his deep affinity for the film’s amateur cast.