There was an unearthly quality to the atmosphere inside the Frieze New York art fair, like the air in a plane—still but pressurized, with an unsettling hum—when the fiction writer Ottessa Moshfegh visited to speak about her work one afternoon in May. “I hate this fair already,” she said when she walked in, handing her ticket to a very tall, very pale man dressed entirely in black lace. Almost immediately, she was lost in the labyrinth of works for sale: Takashi Murakami’s lurid blond plastic milkmaids with long legs and erect nipples; the words “any messages?” spelled out in neon tubing. It was like an enactment of the world inhabited by the protagonist of Moshfegh’s forthcoming novel, “My Year of Rest and Relaxation,” who works at a gallery in Chelsea, amid objects like a quarter-million-dollar “pair of toy monkeys made using human pubic hair,” with camera penises poking out from their fur. “Did I do this?” Moshfegh said, only half kidding. She sometimes gets the sense that she has the power to conjure reality through her writing.

Though the details of Moshfegh’s books vary wildly, her work always seems to originate from a place that is not quite earth, where people breathe some other kind of air. Her novella “McGlue” is narrated by a drunken nineteenth-century sailor, with a cracked head, who isn’t sure if he has murdered a man he loves. “Eileen” is the story of a glum prison secretary, in the mid-nineteen-sixties, who is disgusted by her gin-sodden father and by her own sexuality (the “small, hard mounds” of her breasts, the “complex and nonsensical folds” of her genitals). Moshfegh’s characters tend to be amoral, frank, bleakly funny, very smart, and perverse in their motivations, in ways that destabilize the reader’s assumptions about what is ugly, what is desirable, what is permissible, and what is real. In her collection of short stories, “Homesick for Another World,” a little girl is convinced that a hole will open up in the earth and take her straight to paradise, if only she murders the right person. These characters share with their creator an intense sense of alienation, which she wrote about in a faux letter to Donald Trump: “Since age five, all of life has been like a farce, an absurd performance of a reality based on meaningless drivel, or a devastating experience of trauma and fatigue, deep with meaning, which has led me into such self-seriousness that I often wonder if I am completely insane. Can you relate at all?”

In the sprawling Frieze complex, Moshfegh found the tented room where she was meant to speak and got settled on a little stage in front of a few dozen people. She told them about the case of cat-scratch fever that she contracted in 2007, when she was working as an assistant and living in Bed-Stuy. A street cat leaped into her arms one night; when she brought him home and tried to wash the fleas off, he clawed her face. Hence “the illness that forced me out of New York City—which was a fucking godsend,” Moshfegh said. “Living in New York as a writer felt really claustrophobic; it seemed like everybody I knew had a similar ambition, and it was to be the standout literary voice of your generation, which I think is an insane ambition to begin with.” Moshfegh, who is thirty-seven, and looks like a skinny, Persian Anne Bancroft, was wearing black jeans and boots, an olive-green shirt, and a gold necklace that resembled an abstract spoon. Her peers back then believed, “Whatever it is that you’re going to do, you can’t just fit into the mold—you have to break the mold, blow people’s minds, do it perfectly, and then not care,” she continued. “Because if you care you’re not cool, and if you’re not cool you’re shit.”

Except for the not-caring part, Moshfegh had just offered a pretty accurate description of what she has accomplished. Her breakthrough novel, “Eileen,” won the PEN/Hemingway Award and was a finalist for the Man Booker Prize and the National Book Critics Circle Award. Scott Rudin bought the film rights. The Times said, of Moshfegh, “You feel she can do anything.” The Los Angeles Times declared her “unlike any other author (male, female, Iranian, American, etc.).” Part of what readers found so startling about the book was its female antihero, who is everything women are not supposed to be: “ugly, disgusting, unfit for the world,” as Eileen describes herself, but also angry, self-pitying, resentful. At the prison for wayward boys where she works, a girl comes in one day to confront her rapist, and Eileen snubs her. “I don’t know why I was so cold to her,” she muses. “I suppose I may have been envious. No one had ever tried to rape me, after all.”

Moshfegh created “Eileen” by being, according to the formula she had articulated, the antithesis of cool; she cares so deeply about her writing that it has come close to driving her crazy. For a long time, she was convinced that producing her best work required a monkish commitment to abstemiousness and isolation. “My life got really, really narrow,” she told me. “It’s not like I didn’t have adventurous experiences—my life had been interesting—but I was, like, No, no, no: not that. Just this. I was psychically tortured.”

In response to a question at Frieze on how she stays motivated, Moshfegh told a story about an ex-boyfriend. “He told me in the middle of an argument that being an artist was something that weak people indulge in, and I made him leave, because I guess what I feel is the opposite of that,” she said. “I think art is the thing that fixes culture, moment by moment. I don’t really feel a reason to exist unless I feel my life has a purpose, which is creating. So I feel—I’m not going to call it pressure—I feel I have a karmic role to play.” In her fictional letter to Trump, Moshfegh wrote, “Do you feel you’ve been chosen by God for a special task to accomplish here on Earth? I do.”

The blocks around Moshfegh’s apartment, just east of L.A.’s Little Armenia, are bedraggled: laundry hangs on a chain-link fence; the yards are yellow patches of dead grass on dust; water drips from an old air-conditioner in a window covered with tinfoil. But Moshfegh’s building, a two-story cluster of nineteen-twenties apartments, sits behind a gate, connected to the street by a walkway lined with roses and spindly purple skyflower. “I like it here,” she said in her living room, a clean, quiet space, which she had furnished with a burgundy couch, a Danish modern coffee table with a porcupine sculpture on top, and books lined up on the floor. She wore sandals and had her hair in a braid; all the windows were open, and the air smelled like rain. “It feels like a retreat.”

The unkempt neighborhood outside recalls the sort of place where many of her characters live. An alcoholic teacher in Moshfegh’s short story “Bettering Myself” begins her tale, “My classroom was on the first floor, next to the nuns’ lounge. I used their bathroom to puke in the mornings.” McGlue is forever “in the mud, drunk and tired and unwatched.” It is likewise the kind of setting where one might expect to find the characters of one of Moshfegh’s influences, Charles Bukowski, the late author of “All the Assholes in the World and Mine,” among dozens of other books, whom Time once called the “laureate of American lowlife.” Moshfegh told me that when she encountered his writing, in grad school, “I was, like, Oh, I can write about that, too.” The underbelly of human behavior and emotion could be literature, if it was approached with sufficient precision and passion. In “Eileen,” the narrator recounts the working of her bowels with relish: “With the laxatives, my movements were torrential, oceanic, as though all of my insides had melted and were now gushing out, a sludge that stank distinctly of chemicals and which, when it was all out, I half expected to breach the rim of the toilet bowl. In those cases I stood up to flush, dizzy and sweaty and cold, then lay down while the world seemed to revolve around me. Those were good times.” Moshfegh once told Vice, which published some of her early work, “My writing lets people scrape up against their own depravity, but at the same time it’s very refined . . . it’s like seeing Kate Moss take a shit.”