Wait, weren’t we promised an atomic blast? Where’s our explosion, our fallout, our mushroom cloud? The nuclear suspense of the title is hardly supported in this odd little film from Uruguay. Director Pablo Stoll casts his brother, Juan, as a 20-something slacker still living in his parents’ suburban home. The film simply follows Juan for a day, as he wanders from his late-night bakery shift to snooze at home, then bikes to eat lunch with his girlfriend, then blows off a job interview, hops a train to a seaside resort where he plays soccer, has sex, and barbecues some chicken, and finally returns to Montevideo to meet his brother at a club. All of which is less exciting than it sounds—like your average day of errands, perhaps, only with less talk. That’s because all the dialogue is matted out and replaced with title cards, as in a silent movie. There are sound effects and wall-to-wall Uruguayan music, some of it quite good, seeping from Juan’s headphones. But when a dog barks, silently, and you read “Arf! Arf!” onscreen, what’s the point? That Juan is noncommunicative and borderline autistic could be equally well conveyed in a film with spoken dialogue. (No matter what he’s asked, Juan’s response is “Sure.” He’s just an hombre who can’t say no.) Unless perhaps director Stoll is reaching for metaphor? Is all of economically stagnant Uruguay likewise deprived of its voice, just like this passive idiot savant? The movie leaves you guessing, and Juan’s final act of expression only deepens the enigma.