The moment, when it comes, is devastating in its sheer emotional force. She walks into the room where her children are playing, and the first thing they notice is her black dress. The daughter asks why she’s dressed like that. “This is how we dress when something sad happens,” she tells her. Then the little boy asks when their daddy is coming home. She crouches down next to him and speaks to him as plainly and as honestly as she can. “Daddy had to go see your baby brother Patrick in heaven,” she tells him. The line wasn’t even out before my wife was sobbing next to me; I was bleary-eyed myself, because in that moment, we were both thinking about her having to say something like that our child. Right then, we weren’t watching one of the most iconic women of the 20th century telling her children about one of the turning points of American history. We were watching a heartbroken mother, in perhaps the most painful conversation of her life.

The woman, of course, is Jackie Kennedy (Natalie Portman), the film is Jackie, and the director is Pablo Larraín (No, the forthcoming Neruda), who wisely chooses not to exhaustively dramatize her long, complicated life. Instead, we have another testament to the effectiveness of the snapshot biopic – films like Selma and Lincoln, in which we zoom in on a collapsed period of time to understand an important figure, rather than trying to smash their entire life into two-ish hours. So Larraín and screenwriter Noah Oppenheim instead stick, almost entirely, to the hours and days following her husband’s 1963 assassination.

That event has been dramatized so often that it’s hard to imagine what another film could possibly add, and just to be safe, Jackie basically sidesteps the assassination itself for much of its running time. No one has to have it explained, obviously, but Larraín also doesn’t seem to see much value in reenactment; he’s more interested in an image like her first moment alone, mere minutes after, a devastating close-up of her tear-bleary eyes and drops of blood on her face.

It’s an astonishingly personal portrait, in other words, and the narrowness of its scope – temporally if not emotionally – allows Jackie to really contemplate what that ordeal must’ve been. So we’re with her as she rattles around with aides and replacements in the hours immediately thereafter. We watch as she removes those bloody clothes (Larraín is well aware of the iconography of that pink dress, and leans into it). She drinks, smokes, listens to records. We eavesdrop on the minutiae and logistics: travel, body disposal, funeral preparations, packing up the Oval Office and the White House.

A rough structure is provided in the form of her interview with an unnamed journalist (Billy Crudup, excellent), a week after the assassination. With him, and throughout the picture, she is in absolute control. “I know you think I’m some silly little debutante,” she all but spits at Bobby Kennedy (Peter Sarsgaard, also very good), and when she loses her composure with the journalist, she takes a drag off the cigarette he cannot write about, and assures him, “Don’t think for a second that I’m going to let you publish that.”

But in talking to him, she works her way through that impossible week; he wants, in her words, “a moment by moment account,” but Larraín and Oppenheim eschew that for something closer to a stream-of-consciousness talking jag. He mentions the TV special of her White House tour, and we jet to its production; during that special, she mentions a significant music performance, so we flash back to it. Memories and moments are cued by offhand references and casual mentions, as they so often are – that’s the way we think back on things, organize our thoughts and lives, and is thus the film’s most effective method of putting us in Mrs. Kennedy’s head. It’s a thrillingly unconventional picture, surprisingly experimental and experiential, walking us through those most private moments and daring us to imagine their intensity.

Portman captures that intensity, in a tough, hard-edged, yet vulnerable performance. It’s highly stylized – you often get the sense of watching a performer playing a performer – and the choices Oppenheim’s script makes about when to pop in (and for how long) give it an almost operatic quality. Yet the fire in her eyes keeps us guessing, and Larraín keeps hold of them by choosing to shoot in a sometimes uncomfortably close manner, in tight close-ups and two-shots, with conversations pitched almost directly into the lens. Her elegance, pedigree, and fame made her seem the most remote of figures, but for 100 minutes, Jackie seems to exist alongside her; in its best moments, it underscores the common humanity that’s so easy to undervalue, what with all the regality of “Camelot.” It’s an electrifying and unexpected piece of work.

Jackie is out tomorrow in limited release.