A bleak drama about women struggling to survive in the male-dominated, industrializing countryside of Wales in the nineteenth century, “Gwen” at first carries suggestions of supernatural evil afoot, but ultimately William McGregor’s debut film discloses that the real horror lies in man’s capacity for cruelty and greed. While visually striking and atmospheric, the film is hobbled by its narrative murkiness.

The audience’s perspective is that of the titular character (Eleanor Worthington-Cox), a teen scraping out a living with her mother Elen (Maxine Peake) and younger sister Mari (Jodie Innes) on a desolate plot of land in craggy Snowdonia, where they raise potatoes and keep a flock of sheep. Elen’s husband is gone—she tells the girls that he’s off soldiering, and will return to them, though there are suggestions that’s not the case.

The region is suffused with death: a family living nearby has died suddenly—it’s announced they succumbed to cholera—and the heart of an animal is nailed to the door of the women’s isolated stone cabin, a perpetually gloomy place where Gwen hears strange noises, sees wispy apparitions, and has nightmares—while the wind shrieks constantly outside under a slate-gray sky. The mood of foreboding is made all the more dire by Elen’s strictness with the girls, which can take a sharp, nasty edge.

Elen is also subject to increasingly frequent fits, which lead her to shut herself up alone in her room at night, cutting her arms, though whether as a primitive mode of medicinal bloodletting or as some sort of occult practice is not clear. Gwen seeks help for her from a kindly local doctor (Kobna Holdbrook-Smith), but while he provides a bottle of medicine, he explains that she will need to pay for it, since his master, the local mine baron, is not a generous man.

In fact, Elen is in particular disfavor with him, since she is a hold-out against his effort to expand his empire by acquiring more land for his quarry. When the family’s sheep suddenly die and their potatoes spoil, it might be his work—or, alternatively, the result of some inexplicable malignant force. What’s clear is that as Elen’s malady becomes public, local hostility to her grows, despite the sympathy shown toward Gwen by one young man.

The escalating mini-war reaches a climax in a stunning act of brutality, an attack on the family’s home by a mob of torch-carrying locals, preceded by a direct assault on Elen that she and Gwen respond to with extreme prejudice. But as is noted at one point, if a man steals a loaf of bread they put him in jail, but if he steals a farm, they make him a lord; the conclusion of “Gwen” is depicted as inevitable, given the callousness of the time and place.

What most stands out in “Gwen” is the performance of Worthington-Cox, who gives Gwen a look of haunted desperation that is compelling throughout. Peake does good work, too, but in a distinctly subordinate role, and no one else in the cast really stands out.

The other exceptional element in the film is the visuals. Taken together Laura Ellis Cricks’ production design, the set decoration by Candice Marchlewski and Ellie Pash, Dinah Collin’s costumes and Adam Etherington’s cinematography create an ambience of darkness and dread that overlays the veneer of historical accuracy with a gothic sensibility. The backgrounds give the story a Dickensian feel in which Worthington-Cox, in particular, can shine.

And yet while one can respect much about “Gwen,” overall its dilatory pacing—courtesy of McGregor and his editor Mark Towns—italicizes the fact that the script is somewhat muddled and confused. Perhaps that is intended to reflect the title character’s state of mind, but it doesn’t make things any more accessible for a viewer.

One can therefore chalk the movie up with the old cliché—a promising but uneven debut.