Like its heroine, the paleontologist Mary Anning, Ammonite is a hard movie to love at first. It’s terse and aloof, full of craggy edges that keep you from getting too close. But, also like Mary and the sea rocks she tends, Ammonite‘s hard exterior eventually gives way to something beautiful.

The 19th Century romance starring Kate Winslet and Saoirse Ronan arrived at this year’s strange version of the Toronto International Film Festival as one of the most highly anticipated titles, and is now available to rent on VOD. Directed by Francis Lee, who made 2017’s God’s Own Country, it’s a queer period romance that is bound to draw comparisons to last year’s Portrait of a Lady on Fire, given that it’s also a Neon release and takes place largely by the sea. But Lee’s intentions are much different than Céline Sciamma’s, and Ammonite does not aim for, nor does it conjure, the same heart-swelling moments. Instead, it’s a somber portrait of a woman locked in her own intransigence, an armor she built up to protect herself in a time when a woman of her class and intelligence had few options.

When the film begins, Mary is living a near-hermetic life with her mother in Lyme, England, scouring the cliffs for fossilized treasures and running a small gift shop for tourists. She’s visited by Roderick Murchison (James McArdle), a pompous hobbyist geologist who wishes to leech off Mary’s knowledge before he goes on a globe-trotting expedition. He’s accompanied by his wife, Charlotte (Ronan), a woman he deems suffering from melancholia, but is very obviously in a state of deep despair mixed with an unknown trauma. Roderick goes off on some foreign journey and asks Mary to entertain Charlotte while he’s gone. Mary reluctantly agrees because she’s in need of the funds he offers; Charlotte isn’t too pleased about the arrangement either.

Still, after Charlotte falls ill, Mary’s role evolves from chaperone to caretaker, and they turn from acquaintances into roommates. Friendship and eventually lust blossoms. Ronan plays Charlotte as slightly spoiled and naive as to the ways of people with fewer means than her, but neither timid nor virginal. She’s impish and takes pleasure in goading Mary, sensing their mutual attraction before the older woman will allow herself to act on it.

But Lee is less interested in Charlotte than he is in Mary, and it’s Winslet’s performance that anchors the whole project. Winslet is committed to appearing as unvarnished as possible, contorting her face into Mary’s scowl, cultivated from years of exhaustion, hard work, and little recognition. She’s disinterested in the prim world Charlotte occupies, evident in one of their early meetings when she pees on the rocks, wipes her hands on her dress, and then hands her companion a hand pie she pulls from her bag to eat. Eventually, Charlotte brings out the tenderness in Mary, but there are few moments when we see her without some sort of guard up. She’s as harsh as the wind that blows on the coast, which, at times, drowns out anything else in the sound mix. Winslet’s performance often recalls Timothy Spall’s in Mike Leigh’s biopic Mr. Turner.

Lee’s screenplay deliberately avoids exposition, allowing the audience to infer these women’s backstories through small gestures and what’s left unsaid. That is particularly true of Mary’s interactions with Fiona Shaw’s Elizabeth Philpot. Their shared history is never described, but Elizabeth’s determination to probe Mary’s psyche illuminates what might have been.

Unlike so many historical LGBTQ love stories, Ammonite does not have a tragic ending, and the persecution that Mary and Charlotte would likely face hangs in the background of their interactions, rather than guides the narrative. It’s a personal, intimate story about a woman clinging to the little pride she has and how her elusive happiness could threaten that. When Mary and Charlotte’s time together finally explodes with passion in a sensual and extended sex scene, it takes you by surprise. That passion is hard won. Ammonite makes you chip away at the layers of a hardened soul before finally reaching it.