Santiago Loza’s debut feature comes across with impressive surety, demanding that we tolerate its nonverbal mysteries. And we do. A gliding, palpably quiet event, Extraño is a film, its maker explains, of fragile silence. But too much explanation is unnecessary, and would break the spell: The movie raises intriguing questions about its characters in part by deliberately saying nothing to answer them. Axel (Julio Chávez), a surgeon who’s prematurely retired for unstated reasons, lives in a kind of waking hibernation in his sister’s house. Axel’s nephew joins him in feigning the responsibilities of adulthood, nonchalantly smoking, perusing pornography, and, of course, not saying much. By chance, Axel meets a young woman (Valería Bertucelli) who’s as pregnant as the movie’s pauses; they form a relationship whose only salient feature is the fact of no longer being strangers. Superbly articulated by his cast, the director’s preference for muting his rich material is a feat of cinematic intimacy.