Let us go back to the days when homosexuality was “the love that dare not speak its name,” when women discovered, with no help from science or literature of public figures as examples, their same sex attraction for other women.

The lesbian period piece is practically a genre unto itself, with sexual “awakening” stories “Lady on Fire,” “A Quiet Passion,” “Collette,” “The Favourite,” “Ammonite” and “The Bostonians” and others finding quiet desperation in an age where women were “property” and propriety lashed them into corsets and arranged marriages.

A running thread through such dramas is their secrecy, with passions heightened because of that “hidden/forbidden love” secrecy.

“The World to Come” adds little to that proven formula. The novelty here is that two rural, little-schooled 19th century farmwives find love and passion with almost no outside influences, nothing to tell them if what they are feeling is unique and freakish, or why exactly it might be “wrong.”

The film, starring two fine British actresses — Katherine Waterson and Vanessa Kirby — and based on a Jim Shepard short story, may have a primitive not-quite-frontier setting and hints of the brutality of that. But it’s otherwise just as idealized and romanticized as the many versions of this story among aristocracy, wealth, fashion and always-perfect hair and makeup.

Waterston (“Alien: Covenant”) is Abigail, an upstate New York farm wife who loses herself in her chores and “responsibilities” and her “ledger,” a daily journal she keeps, at her husband’s (Casey Affleck) suggestion as a way of charting the emotional life of their farm and their family.

“Family” is a term she might put in the past tense. They lost their daughter to diphtheria the preview fall. Thus “with little pride and less hope we begin the New Year,” she writes and narrates.

“I have become my grief.”

But 1856 and its cooking, mending, cow-milking and chicken-tending, changes for Abigail when a new couple moves into the farm next door. Finney (Christopher Abbott of “Whiskey Tango Foxtrot”) is an officious Bible-quoting boor. But Tallie (Kirby, of “The Crown” and “Pieces of a Woman”) is a redheaded, freckled vision of vivaciousness to lonely, provincial Abigail.

“Her skin had an under-blush of rose and violet,” Abigail narrates, so smitten that “I had to look away.”

Thus do they strike up an intimate friendship, discussing their lives, their men, their chores and their dreams. Tallie seems to be on strike from an unhappy marriage of obligation. Abigail finds herself neglecting her own share of the farm labor and even more reluctant to abandon the grief-induced sexual separation from husband Dryer.

The women share poetry and longing looks, with Kirby (Natalie Dormer, The Next Generation) devouring Waterston with her eyes, tempting the never-left-this-county plain Jane with her voluminous, curly locks.

The husbands respond to this attachment and distraction with Old Testament fury and not-quite-direct threats, on Finny’s part — “I have certain expectations and you have certain duties” — and bewilderment on Dryer’s — “There is something going on between us that I cannot unravel.”

For all the immaculate perfection that the simmering might-become-lovers are filmed in, director Mona Fastvold takes some pains to show the cruelty of the times, the harshness and isolation, even in the long-settled but still underpopulated rural East of mid-19th century America.

The pitiful screams of pigs being slaughtered, the unforgiving and relentless winter, the grim risks of running into strange men on the road or having no doctor to fetch when fevers set in all remind us of the stresses these characters and these marriages start out with it. Add potential infidelity of a Leviticus unleashing nature and you appreciate the desperation of these women, the dire circumstances they want to escape — if only for a few hours –and the consequences of the risks they’re taking.

All of which, frankly, we’ve seen on screen many times before. Such period pieces have become as commonplace as “coming out” stories.

The leads are riveting in their respective roles, even if we never forget how idealized the characters seem.

Norwegian actress turned director Fastvold (The Sleepwalker”) modulates the tone of the picture and the feelings of the characters with weather, a greyscale of wintry gloom until they meet, the alarm of a whiteout blizzard, a little sunshine almost breaking through as the would-be lovers cautiously begin their flirtation.

Romania nicely substitutes for Appalachian upstate New York, and the film has a grimy air of mud, blood and struggle about it.

But lovely as it sometimes is and impressive as the cast may be, it holds too few surprises and dramatic peaks to make it a stand-out in a genre that’s fast-becoming old 19th century hat.

MPA Rating: R for some sexuality/nudity 

Cast: Katherine Waterston, Vanessa Kirby, Christopher Abbott and Casey Affleck.

Credits: Directed by Mona Fastvold, script by Ron Hansen and Jim Shepard, based on a short story by Jim Shepard. A Bleecker St. release.

Running time: 1:38