The most disturbing cinematic sequences often owe their ability to shock to an uninflected, matter-of-fact presentation. Michel Franco’s Daniel & Ana revolves around a doozy: Kidnapped, the titular pair of wealthy Mexican siblings is forced at gunpoint into an act of incest, while their captors tape the proceedings. For his part, Franco films the graphic intercourse in a trio of real-time fixed takes, the combined pleasure and agony of the couple’s groaning and the reluctant grind of their bodies set off against the antiseptic white of the room. The ultimate act of voyeurism, for us as well as the fictional pornographers, it casts its sickly pall over the rest of the film as sure as it does over its characters. While Daniel and Ana struggle to resume their daily lives—the former starts skipping classes, the latter breaks off her impending marriage—Franco captures the minute details of altered lives with reserve and sensitivity, effectively asking the viewer to share the characters’ sense of shame as they shrink from all human contact. Too bad the director blows it with a last act that tips the film’s delicate balance over into lurid grotesquerie, even as his staging remains as consciously muted as ever.