Credit: Benjamin Loeb / Netflix

In the unbroken, nearly 25-minute scene that opens Pieces of a Woman, Vanessa Kirby’s heavily pregnant Martha — delirious and deep into labor — groans and sighs, grunts and screams; at one point she trills like a bird, eyes wide and puzzled by the pain. It’s the kind of bravura performance that critics love (rightly) to call a masterclass; more than that though, the movie’s bow at the Venice International Film Festival last September seemed to signal something else: That Kirby as an actress — of the sort whose capital A is somehow invisible but heavily implied — had arrived.

She's not unknown, of course, to uncountable fans of The Crown, for which her spiky, tenderhearted Princess Margaret earned both an Emmy nod and a BAFTA, or to anyone who caught her too-brief turn as the platinum-cool White Widow in 2018’s Mission: Impossible - Fallout. (She is already filming the next two sequels.)

But Pieces, on Netflix now, does feel like a kind of tipping point. Not because it’s a great movie; after that indelible birth scene ends in almost unthinkable tragedy, the narrative begins to crumble — less a satisfying story arc than a disjointed melodrama punctuated by grand, improbable monologues. Still, Hungarian director Kornél Mundruczó (White God), working in a kind of spacious ’70s New Cinema style, does something that's often hard to find on screen these days: He gives Kirby the room not only to rage and grieve, but just to be. (And also pulls remarkable turns from her costars, including Ellen Burstyn, Shia LaBeouf, and Molly Parker, as the midwife who shoulders the blame.)

When we first meet Martha, with her chipped black manicure and deliberately messy morning-after hair, she seems like the kind of casual Cool Girl whose decision to have her baby at home — a lovely light-filled townhouse she shares with her partner, Sean (LaBoeuf) — is one more choice, like a juice cleanse or painting the nursery in soothing gender-neutral colors, provided by her comfortable millennial lifestyle. There’s clearly a class difference too with Sean, whose rough edges and construction job telegraph a humbler kind of background.

He has his own private bereavement to get through, though everyone, including Martha’s anxiously overbearing mother (Burstyn) and more sympathetic sister (Iliza Shlesinger), seems to have ideas of how they each should be processing the loss — up to and including a lawsuit against the doula they hold responsible. That’s also when the script (by Mundruczo’s partner and frequent collaborator Kata Weber), starts to lose its moorings, abandoning the raw delicacy of its character-study tone for something broader and much less believable.

Though an overwrought final hour dissipates the power of the first and its soft-focus end notes feel unearned, the film still leaves a bruising kind of mark. That’s largely a testament to the uncommonly lived-in performances of LaBoeuf (despite the troubling recent accusations against the actor, he’s extraordinary) and above all Kirby, who makes Woman's scattered pieces come utterly alive, if never entirely whole. B–

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