“It’s a bit scary to put my face out in public after all these years,” says Kiran Desai, who has emerged from 20 years of writerly solitude with the publication of her third novel, The Loneliness of Sonia and Sunny (Hogarth, September 23), already longlisted for this year’s Booker Prize. The Indian-born author shot to literary stardom when she won both the Booker and the National Book Critics Circle Award for her previous novel, The Inheritance of Loss (2006). “It’s almost as if I didn’t notice all those years passing, but my hair went gray in between.”

Will she join Hilary Mantel and Margaret Atwood among the two-time Booker winners when the prize is announced this November? “I don’t think so,” she demurred, looking slightly terrified by the prospect. Our reviewer, who called the book “a masterpiece,” might beg to differ. We caught up with Desai over Zoom to learn more about this leviathan project; she spoke to us from her home in the Jackson Heights neighborhood of Queens, New York. Our conversation has been edited for length and clarity.

What was the original idea when you first set out to write this novel, two decades ago?

I wanted to write a love story, a globalized love story. I also wanted to write about loneliness, which of course is the other side of love. As I set the story out in the big world—the United States, India, Europe—I realized that the idea of loneliness could include not just romantic loneliness, but all the rifts in our modern world: race, class, distrust between nations, the division between rich and poor….It was an exciting moment for me when I understood that I could see loneliness in all these different ways.

There are a lot of water images in this book, and I began to think of loneliness as ever-present as water, moving from one form to another. Not just the difficult side of it, but also solitude as sustenance, as a time of recovery and reinvention.

How does one start a project that ambitious?

I began just by keeping diaries, by sitting down at my desk every morning and writing diaries every day, slowly extending the arguments and building up the material. I had developed a very strong discipline while writing The Inheritance of Loss, and it stood me in good stead. I had to trust that clarity would emerge—and plot, of course.

That sounds something like your character Sonia’s process—she, too, is a fiction writer. But after she’s been working for many years, she begins to doubt. “Would these stories intersect and make a book? How would they hold together? How to be trusting like an ant, do your part to sustain what existed beyond your vision? What if she stepped back and surveyed what she had wrought and saw that it lay in incoherent pieces?” Were there times when you felt like that?

In about 2013 or 2014, I was at a residency and finally printed out what I had so far. It was a shocking number of pages—about 5,000. A monster. I had to throw out an enormous amount—a whole section set in rural Kentucky, for example, is gone altogether, and several chapters from the German past of Sonia’s grandmother are down to one quick reference.

What kept you going?

It turned out I needed a visual symbol, which I didn’t quite realize until I found one, or it found me. I received a message from the painter Francesco Clemente, asking me to write an introduction to his exhibition. As a gift, he sent me a painting which was part of the exhibition—a little painting of a figure that has no eyes, no face, just this cracked open void. That became Badal Baba. He is the deity of the book, a deity for characters who have lost their sense of self and cannot see themselves in the mirror.

Badal Baba is the amulet that Sonia’s mother gives her, which gets lost and drives a lot of the plot.

Yes, that image was on my desk the whole time, and it helped me tie the different strands of the book together. It was quite interesting to see how a painting becomes a novel, how it infiltrated the book and became part of its secret structure: Who is captured by whose gaze?

Is the character of Ilan, the famous painter in the book, based on Francesco Clemente?

[Laughing.] No, no, Francesco Clemente is the sweetest man in the world. Very gentle. Maybe he would be pleased to be presented in this notorious way, I don’t know. But no, it’s not based on him.

For a large part of the story, Sonia’s amulet ends up in Ilan’s hands.

And he uses it to steal her story. I was thinking about provenance, who owns the art, who gains in power.

Sonia and Sunny are both writers—what was behind that choice?

I think Garcia Márquez said something like, Fiction and nonfiction are two wings of the same bird. On the nonfiction side, Sunny is a writer for the Associated Press, obsessed with and disconcerted by the news, how it morphs from country to country, depending on who tells the story. Sonia is worrying about similar things in fiction, grappling with ideas of the novel and of storytelling.

In fact, Sunny has a theory that to be a good novel reader you have to be a good toilet cleaner. Toilet cleaning comes up quite a bit in the book.

Well, you know, Indian society is still based on class and caste. Cleaning toilets was the work of those who were called “untouchable,” and there are a great many people in India who have never, ever cleaned their own toilets.

Sunny is meditating on the poor sales of fiction on the Indian subcontinent—really strikingly low. Perhaps this is because at the heart of any novel is an individual, one person whom you get to know—their shames, their fears, their lives, their thoughts. Once you begin reading novels, you are able to identify with another person, to see them as fully human. As Sunny thinks of it, Gandhi may have successfully ejected the British from India but he failed in his exhortations to get Indians to scour their own toilets—and thereby fathom the basic meaning of human rights.

For Gandhi, cleaning toilets was part of a spiritual practice. I find that in writing a book, cleaning my house, washing my dishes, taking out my garbage, cleaning my toilet—all of that is part of the writing process, part of the same discipline.

 You’re the daughter of the celebrated novelist Anita Desai. Do you two share work?

My mother and I are very close, but she is totally private about her work; she shows no one what she’s working on before she submits a completed draft to her editor. I read it in galley form. With my work, on the other hand, she’s the first reader. She read a draft of Sonia and Sunny when it was still a thousand pages long. I was still struggling to end the book, to bring all of the themes together. I tried several endings. At one point she said, “I think you have it.”

Marion Winik is the author of The Big Book of the Dead and hosts the Weekly Reader podcast on NPR.