Martha Weiss (Vanessa Kirby) and Sean Carson (Shia LaBeouf) are exuberant in anticipation of the birth of their first child. They choose a home birth for their daughter, but it ends in tragedy. Now they and their families must cope with the grief of their loss, while Sean and Matha's mother Elizabeth (Ellen Burstyn) take a legal route to seek compensation.

'Pieces of a Woman' features a stunning first act, distinguished by an extraordinarily moving and beautiful long take following Martha in labour. This shot is truly the highlight and most enduring accomplishment of the movie. The performances from the cast - which also includes Molly Parker, Sarah Snook and Iliza Shlesinger - are all really impressive as well. It is the best performance of Kirby's career to date, while LaBeouf is also remarkable. Burstyn too nails the overbearing mother role, managing to make her daughter's pain all about her own. But cinematography (from Benjamin Loeb) and acting aside, 'Pieces of a Woman' has some flaws.

Its narration ebbs and flows with a sense of discontinuity that one could write off as reflective of its theme of grief, but is really down to Kornél Mundruczó's uneven direction. There's something of an imbalance as it tries to be both festival darling and conventional drama, with the actors left largely on their own to figure out what tone they want to convey in a given scene. But the movie's biggest shortcoming of all comes in the courtroom drama that characterises the third act. Here we get a soliloquy that feels hammy as well as unrealistic, and too on the nose when so much that preceded was conveyed subtly and poignantly. There are other events of the narrative that also feel forced, but one can't delve into them here for they involve spoilers.

'Pieces of a Woman' is still, for the most part, very moving, which is not only due to the nature of its story line, but the aforementioned performances. The ending proves satisfactory and if Kirby doesn't receive the Oscar for her performance, she's sure to get a nomination. She conveys the confusion, coolness, fury, and desolation of what her character is going through with a penetrative force. Kirby has more than proven she has so much more to offer outside her performance as Princess Margaret in 'The Crown'.

'Pieces of a Woman' is streaming on Netflix from Thursday, 7 January.