Bergman at his darkest in The Silence

I don't exactly see how Ingmar Bergman's The Silence (1963) fits as the 3rd of a trilogy except perhaps that all three (Through a Glass Darkly, Winter Light) are about people in severe emotional distress and isolation, feeling alone, having no connection w/ the lives of others, no spiritual life, and suffering from stifling and artistic or professional failure and misunderstanding - except this list could characters almost any Bergman film over the first half of his career (comedies excepted). It's amusing to see that in its day The Silence was considered by many to be pornographic, making the film a success de scandale and one of Bergman's most financially successful. Today the sex scenes seem understated and discrete; things have changed. The film itself is a powerful and mysterious chamber drama, focused on 3 people: two sisters perhaps in their 30s - the elder, Ester, apparently unmarried and childless and working as a literary translator, and the younger, Anna, and her son, about 10?, Johan. We know almost nothing about their back stories; the film begins as they're traveling by train - presumably heading home to Sweden though it's never clear where they have come from or why - when Ester becomes ill and they stop in an unnamed city in what seems to be Eastern Europe, perhaps under Soviet siege (there are tanks at the train station and in the streets). They take a suite in an old hotel - high ceilings, long corridors, many chandeliers, the kind of place typical of Eastern Europe and Russia at one time - where Ester tries to recover and Anna goes off into the city in search of sex. They, particularly A., ignore Johan, who roams the corridors alone and has several odd and disconcerting encounters, especially toward the end when he sees his mom w/ a man she's picked up. Neither of the women speak or understand the local language, not can they find a common language (other than sex) w/ anyone whom they meet. The film ends as A and J head home on another train, leaving they dying E behind. As with many Bergman films, there are striking tableaux and close-ups of half-shadowed faces, and many mysterious moments: an encounter with a vaudeville troupe of men w/ dwarfism, views from the window of military maneuvers, meetings with the strangely sympathetic, elderly man who seems to be a concierge - although maybe a spy? There are no clear answers or resolutions - we never learn where the women have come from, where they are going, or why they seem to hate each other - but the film is imbued with a mood of dread and despair. It's Bergman at his darkest - but I think we're also meant to see the failure of these two women to connect w/ anything in their world - the child, the country they are passing through, the turmoil in the streets - is a malaise that can lead only to death and isolation. His portrait of a lonely young boy who sees more than he should is also significant: Johan could have "grown" into the young, artistic man in Glass Darkly, and he foreshadows the young Bergman avatar in Fanny and Alexander.