Francis Lee returns to the subject of same-sex romance that served him so well in his debut, the Arcadian, bold, and lusty God’s Own Country. It is perhaps a little risky to cover similar ground, but he has recruited two genuine stars in Kate Winslet and Saoirse Ronan for his imagined version of the real-life friendship between palaeontologists Mary Anning and Charlotte Murchison. Ammonite is handsome, beautifully-acted, and far more frank than most period dramas dare to be, but it still feels like something of a dusty museum piece next to such a sensational debut.

Mary Anning (Winslet) spends her days hunting for fossils on the beach at Lyme Regis to sell to tourists. Having previously gained acclaim for her discoveries, the self-taught palaeontologist finds her circumstances much reduced with the craze for prehistoric beasts in the 1830s having settled down. She grudgingly accepts a substantial sum of cash from patronising tourist Roderick Murchison (James McArdle) to take care of his young wife Charlotte (Ronan), who is grief-stricken after a personal tragedy. The two women clash instantly but they eventually fashion a companionship that becomes something much more passionate.

Both of Ammonite‘s celebrated leads are no stranger to a corset and both inhabit their roles like a favourite pair of comfy slippers. Winslet’s Mary has kept all of her sharp edges despite a perennial buffeting from the coastal wind and rain. Ronan’s Charlotte is initially almost catatonic but eventually batters down Mary’s defences with her usual impish energy. For all Charlotte instigates the relationship, Ammonite is a reminder of Kate Winslet’s versatility and quality. She resides in some perfect Venn space between megastar and character actor and can carry a movie while vanishing into a character. While her chemistry with Ronan isn’t quite as immediate and intense as that with DiCaprio in Titanic or with Jim Carrey in Eternal Sunshine of the Spotless Mind, it is still easy to buy their relationship. Unfortunately, the rest of the film is not as dynamic as its leads.

The problem is that Ammonite resembles so many of the stilted period romances against which Gods Own Country acted like such a bracing antidote. Like the fossils Mary so patiently hauls from Dorset’s Jurassic clay, Ammonite is solid, but for many observers the novelty will have worn off. There is nothing inherently wrong here, but it is simply redolent of so many great films. Winslet’s quick-tempered, taciturn Anning recalls Holly Hunter‘s mute Ada in The Piano, the windy seaside location and the female romance is always going to draw comparison with Céline Sciamma‘s superlative Portrait of a Lady on Fire, and it suffers next to his earlier work. Lee has tried to capture the same lightning in a bottle as God’s Own Country, but for all he employs the same earthy, windswept aesthetic it feels less natural, and more self-consciously dramatic.

It also seems like Lee cannot decide entirely on the attitude to gay romance in his take on early-Victorian England. Anning seems to have had a relationship at some point with an elegant older woman (Fiona Shaw), who herself flirts openly with Charlotte at a music recital. Later Charlotte brushes off Mary’s concerns when they are seen kissing by a maid. However, early on Lee lingers on Mary’s reaction to seeing Charlotte’s exposed ankle on the beach. Is Lee gently satirising the stereotype of Victorian sexuality? Is he giving it credence? Or is he giving us some insight into Anning’s own repressed desire? If Anning herself was less of a mystery, perhaps it would be clearer. But despite the wonderful Winslet’s best efforts, she remains essentially calcified, and no amount of careful chipping gets beneath the surface.

Some reviews of Ammonite have criticised the historical accuracy of the film, but its surely now so much of a truism that all manner of liberties are taken with true stories that they’re barely worth pointing out. History is adaptation, no matter how slavishly one tries to stick to established fact. Francis Lee’s portrayal of Dorset and his sense of the period feels authentic, lived-in and tactile and Mary and Charlotte’s relationship feels of a piece with that; hardy, headstrong nature clattering against the perceived primness of England at the time. Like a daisy growing through a crack in concrete, there are some things that won’t be denied. However, there is also too much that is safe and ordinary in Ammonite, which feels like more of a betrayal to the spirit of Mary Anning than any misapplied romantic leanings.

Screened as part of BFI London Film Festival