It is 1862 in a remote Irish village when an English nurse is called in by a local council to observe and investigate a phenomenon in the haunting new film "The Wonder." There is, she's told, an 11-year-old girl who has not eaten food in four months and seems to still be healthy.

The nurse, Lib Wright (Florence Pugh), is to watch the girl, in alternating shifts with a nun — it is Ireland, of course — and report back as to what she observes. They say they'd like to know if it's a miracle or not, though most seem to have made up their minds that they'd rather not actually hear if it's the latter.

The film, from Chilean director Sebastián Lelio ("A Fantastic Woman"), is adapted from a novel by Emma Donohue, the Irish writer of "Room." She was, she's said, inspired by the Victorian Fasting Girls. In the late 19th century newspapers ran stories about young girls, often bedridden, who claimed to have been living without food or water for extended periods of time. Some doctors regarded it as hysteria. Some believed it a holy miracle and made pilgrimages to visit the girls.

Lengthy fasts have long been celebrated in saints and nuns going back to the Middle Ages, perhaps most famously in Catherine of Siena. In 1982, historian Joan Jacobs Brumberg would write in her book that it was undiagnosed anorexia nervosa, though somewhere along the way someone would give religiously motivated starvation its own term: Anorexia mirabilis. Like "Room," "The Wonder" delves into deep, uncomfortable traumas and it will not be for everyone, especially those triggered by depictions and descriptions of disordered eating.

Lelio, who co-wrote the adaptation with Alice Birch, uses a curious Brechtian framing device, opening the film in an empty, florescent-lit soundstage as a narrator, Niamh Algar, invites the viewer into the film. "Hello. This is the beginning. The beginning of a film called 'The Wonder.' The people you are about to meet, the characters, believe in their stories with complete devotion. We are nothing without stories, and so we invite you to believe in this one," Algar says as cinematographer Ari Wegner's camera pans over to a set piece of a boat's cabin and focuses in on Lib.

It is not ineffectively done, but I'm also not sure it adds anything since the film mostly commits to Lib's reality from thereon. Aren't all films inviting us to believe, after all? Though maybe it is something worth repeating. And the sentiment will surely echo in your head as science clashes with religion in what is a very compelling gothic mystery about the curious case of Anna O'Donnell (Kíla Lord Cassidy).

Pugh gives yet another stunning performance, utterly naturalistic and committed, as a skeptical nurse recently back from Crimea with Florence Nightingale, her own private losses haunting her. She is an outsider in every possible way, a woman of science and English, coming to this small, deeply Catholic town that has just emerged from the Great Famine.

Lib is certain that Anna is not telling the truth when she says she has existed solely on "manna from heaven" for four months. She knows she would be dead if that were the case. But also finds herself getting more invested in her subject than she perhaps anticipated. Anna's story has travelled, too, and has become a comfort not just for her parents but for strangers from all over who come to witness the miracle. It's also attracted a journalist from the city, played by Tom Burke, who is both a thorn and a help to Lib on her increasingly frustrating search for truth and facts, which she starts to understand are not so simple in this town.

Early on, Lib asks Anna's mother what her last meal was: It was the Eucharist on her first communion.

"So just water and wheat?" Lib responds.

"No," she's told. "It's the body and blood of Christ."

It's a story to Lib and a fact to believers and they find themselves at an impasse that feels awfully resonant. But science and belief clashes aside, "The Wonder" is a transfixing, transportive film, anchored by the incomparable Pugh.

"The Wonder," a Netflix release playing in theaters and streaming, has not been rated by the Motion Picture Association. Running time: 109 minutes. Three stars out of four.