It’s a Friday afternoon, and Jenny Offill, author of the widely acclaimed 2014 novel Dept. of Speculation (Vintage), is at her home in the Hudson Valley. She’s speaking via Skype, about to broach the subject of her new novel, Weather (Knopf, Feb.), when her internet goes down. The conversation switches to the telephone, but Offill isn’t flustered. In some ways the interruption seems fitting. Both Dept. of Speculation and Weather, with their fragmented structures, suggest that linearity is suspect, that connection is fragile, and that we are at the mercy of forces beyond our understanding.

Offill’s biography, like her novels, is haphazard. Her parents were boarding school teachers, and throughout her childhood she moved around the country, living in Massachusetts, California, Indiana, and, eventually, North Carolina, where she attended high school and college, at the University of North Carolina at Chapel Hill. After graduating, she worked a number of odd jobs—waitress, bartender, caterer, cashier, medical transcriber, fact-checker, writer of “things for rich people who have a story to tell,” as she puts it.

She published her first novel, Last Things (Bloomsbury), in 2000, when she was 30. That book received critical acclaim but failed commercially. In the years that followed, Offill worked as an adjunct writing instructor at various universities and wrote children’s books. Like the writer-narrator of Dept. of Speculation, she struggled for years to produce a second novel.

When she did produce that second novel, it exceeded expectations. “I was hoping other writers would like it,” Offill, 51, says of Dept. of Speculation. “That was just a weird book. I didn’t think a novel that was structured like that would have a big audience.”

For all its unconventionality, Dept. of Speculation is propulsive and absorbing. Critic Elaine Blair, writing in the New York Review of Books, said it can be read “in about two hours.” She’s right. Perhaps this is why it didn’t remain some “weird book,” as Offill assumed it would. To date, Dept. of Speculation has sold about 57,000 print copies in hardcover and paperback, according to NPD BookScan; it has been acquired in 21 territories outside of North America; and it’s been optioned for film.

The novel tells the story of an unnamed woman who once aspired to be an “art monster” but, saddled with family and work commitments (including a gig as a ghostwriter for an egomaniacal “almost astronaut”), has thus far failed to realize her potential. The Wife, as she’s sometimes called, begins to question her devotion to her family when she discovers that her husband has had an affair with a younger woman. Proceeding in a series of frenzied fragments, separated by double paragraph breaks, the novel presents the narrator’s fearsome intellect as well as her changeable demeanor.

In a single brief chapter, the narrator alludes to Einstein, recounts the gruesome death of a Russian cosmonaut, quotes the explorer Frederick Cook, writes an imaginary and self-flagellating Christmas card to loved ones, describes her daughter swimming, and references the Stoics.

Dept. of Speculation’s success may also have been owed, in some small part, to its association with a style of writing, popular in the last decade, known as autofiction. The term has come to stand for a literary approach that does away with the conventions of fiction, such as plot and invented characters, and draws, or appears to draw, on the author’s lived experience.

Offill is often mentioned in the same breath as other practitioners of the form, such as Rachel Cusk and Ben Lerner, but she smarts at the label. “Autofiction has been around for so long,” she says. She also feels it’s gendered, asserting that women who write it are assumed to be pulling from their diaries. “I wouldn’t be a fiction writer if I didn’t believe that you could invent, and conflate, and add to things.” And Weather, while formally similar to Dept. of Speculation, certainly strays from the precepts of autofiction. Its narrator is named, for example, and its preoccupations are less insular.

The book centers on a librarian named Lizzie who is raising a son with her husband and caring for a brother with a history of drug addiction. Over the course of the novel, Lizzie, who begins working for a former mentor who operates a podcast about futurism, becomes increasingly fixated on the climate crisis and the doomsday preparation movement. Her anxieties only accelerate when Donald Trump (who is never named) is elected president.

Jordan Pavlin, Offill’s editor at Knopf, feels that Weather is “more ambitious in its themes” than Dept. of Speculation, and that “one of its most thrilling seductions is the way it uses the anxiety we are all experiencing in relation to the current climate—both literally and figuratively—as a plot engine.”

Offill says that with Weather she was looking to respond to the current moment more directly, to write a book that wasn’t “frozen in amber.” She was inspired to address climate change in part by her conversations with her best friend, novelist Lydia Millet, who has written about environmental issues for the New York Times and who addresses those themes in her fiction. “For years we’ve been talking, and at a certain point I thought, ‘I need to know more about this,’ ” Offill says.

At the same time, Offill worried about the pitfalls of political fiction, which she feels can be boring, didactic, and humorless. “I don’t love the language that’s available to talk about this stuff,” she says. “Do I like to say interconnectedness? No. Do I like to say web of life? Mm, no. If you’re not particularly drawn to earnestness, how do you make yourself be a more engaged person?”

Nonetheless, Offill thinks the central problems of our time—climate change, social justice—can’t be tackled individually. “It’s about getting more people—including people like me, who actually hate all group activities—to sign up for the messiness and frustration and occasional exhilaration of collective action. I’ve been to more marches and more meetings and I’ve written more postcards and called more people than I’ve ever done,” she says. “I don’t like to do any of that stuff.”

Weather, like Dept. of Speculation, is told through frenetic fragments. But where the fragments in Dept. of Speculation were meant to mimic the churning of the narrator’s mind, the fragments here are meant to mimic weather. “People always say, ‘It’s an atmospheric book,’ ” Offill explains. “I wanted to see what it would be like to try to write atmospherically.”

The book, she says, is “meant to swirl” as if its paragraphs were clouds. Its atomized form is intended to congeal into an uneasy whole, mirroring the challenge of political movements, in which individuals must find a way to act in concert.

If Offill arrived at any wisdom by the end of writing Weather, it’s the wisdom captured in a quote the protagonist’s husband posts above his desk: “You are not some disinterested bystander/Exert yourself.” With Weather, Offill hopes to do just that.