Olivia Colman once again places herself at the forefront of the Best Actress Oscar race as the courageously unselfconscious star of Maggie Gyllenhaal's directorial debut, a film about motherhood that gets right to the heart of its middle-aged protagonist, highlighting her many contradictions and flaws, alongside her sparkling charm, intellect and kindness. It's an attention-grabbing, seductive and thoroughly thorny drama, based on the novel by the pseudonymous Italian author Elena Ferrante, with Gyllenhaal penning the screenplay herself.

The first-time director gets right up in the face of her characters as we meet academic Leda (Colman), holidaying alone in a quiet part of Greece. Leda's peace is shattered by the arrival of a brash American brood with criminal connections. She becomes fixated on glamourous young mother Nina (Dakota Johnson), trapped in a tumultuous marriage to a menacing man (Oliver Jackson-Cohen), while Dagmara Domińczyk (showing us what she can do following her small role in Succession) plays the intimidating Callie, the family's pregnant matriarch-in-waiting. Normal People's Paul Mescal pops up as a friendly waiter, Ed Harris is a local handyman, while Peter Sarsgaard is a face from Leda's past, who we see in flashbacks with her younger self, played by Jessie Buckley.

With an unpredictable protagonist driving much of the action, even if she at first seems like a mere observer, there is the permanent sense that things could go sideways and the cultural clashes unfold very enjoyably, as some passive-aggressive and just plain aggressive stand-offs take place between Leda and Callie against contrastingly serene backdrops. Fierce, judgemental and overbearing, Callie thinks she has motherhood sussed before her child has been born, which Leda amusingly and somewhat mischievously calls her on, operating with astonishing fearlessness and risking making an enemy of the whole damn clan.

By delving into Leda's past and considering Nina and Callie, the film explores what a mother is allowed to be and how taboo it is to prioritise your own needs; it sees children as both a salve and burden, an inescapable nightmare and heart-swelling joy. There is much to savour here: from the superb supporting performances, including an irresistibly dreamy Johnson, to humorous episodes, seesawing tension and gorgeous cinematography (courtesy of the great Hélène Louvart, who recently did outstanding work on Rocks and Never Rarely Sometimes Always). But it's a spellbinding Colman that's the film's major selling point. The actress delivers stupendous quantities of depth and conviction; it's hard to imagine anyone else bringing Leda's disparate personality traits together so believably, and creating such a compelling character.

Screening on Wednesday 13, Thursday 14 and Saturday 16 October as part of the BFI London Film Festival 2021.