That opportunity directly followed her mesmerizing turn as one half of a couple disintegrating into divorce in Marriage Story. Johansson had nearly worked with that movie’s writer-director, Noah Baumbach, in her early 20s. When that earlier project fell through, she says that she felt he’d probably never call her again. But a few years ago, he asked to meet. Baumbach explained to her that he was writing a story about a divorce, and Johansson explained to him that she was going through one. (This was from her second husband, Romain Dauriac.)

Johansson is careful not to overplay this synchronicity. On the one hand, she acknowledges that of course her own life experiences were a help: “I had some kind of shared experience with the character, or with any person going through a divorce, really. I understood the bittersweetness of it somehow, in a way. All those kind of in-between feelings that the character has. I understood them because I had gone through them myself.” But she points out that even in terms of her own personal experience of divorce, she drew just as much, or more, on memories of her parents’ struggles than her own.

Also, even though Johansson and onscreen husband Adam Driver have both justly been showered with praise for the visceral, persuasive, moment-by-moment intimacy with which they depict how a marriage can falter, often despite good intentions and love, Johansson emphasizes that what viewers see unfolding on the screen is not the product of some free-form improvisation. “What surprises a lot of people about that film is that every single hesitation, every unfinished sentence, every moment where an actor talks, all of that stuff is scripted,” she says. “It’s just so well written. Every single thing that comes out of our mouths is totally scripted, and nothing is improvised. No hesitation. No ‘If….’ No ‘But….’ It’s all completely scripted, and Noah is so specific about it.”

“The FIRST TIME I got married I was 23 YEARS OLD. Maybe I ROMANTICIZED it.”

All of it is depicted, with remarkable deftness and empathy, in granular detail: the toxic spiral formed in the vacuum at the end of a relationship (particularly when a child is involved); the ways two people, no matter how motivated, can suddenly find themselves sinking to the occasion; and how defense can somehow mutate into the most unsparing kind of attack. It is in the worst of this conflict that Baumbach finds a surprising amount of humor, in a triple master class from the three actors (Laura Dern, Alan Alda, Ray Liotta) playing contrasting lawyers, but it is in the claustrophobic one-on-one scenes between Johansson and Driver that Marriage Story is most special. There’s a new kind of power and low-key realism to what Johansson does here that augurs very well for the next phase of her career.

Notwithstanding the different sources that she has discussed drawing upon, I ask Johansson how different she thinks her performance might have been if she hadn’t been through divorce herself.

“What would have been different,” she replies, “is if I hadn’t been a mom. That was actually more valuable to me than the experience of going through a divorce. Because I never actually went through the kind of divorce that’s portrayed in the film. Yes, of course, part of the film is about the system of divorce, or the business of divorce, and how fucked up it is, but that was Noah’s experience more than mine. But the experience of being a mother was very helpful, and it was a great tool…. You know, understanding what it is to co-parent—that’s a very specific thing. It’s hard to raise a child with someone you’re no longer with. It’s hard. It’s not probably how it’s ‘supposed to be’—in quotes—or whatever…. But, you know, I think my ex and I do it as well as we can. You have to prioritize your child and not put yourself in the middle. It has its challenges.”