Clare Conville of Conville-Walsh, a boutique literary agency within Curtis Brown in the U.K., has pitched her tent in the garden of the Pilton cottage belonging to our mutual friend, mosaic artist Candace Bahouth. Clare and I are here for the Glastonbury Festival, but over tea in the cottage kitchen, the conversation turns to books she’s representing—in particular, Matt Haig’s new novel How to Stop Time. I’m all ears.

The novel, which is being published by Viking in the U.S. next year, follows Haig’s memoir, Reasons to Stay Alive, about his overcoming the depression he suffered at age 24. Published by Cannongate in the U.K., Reasons sold more than 300,000 copies there, and, Clare says, “put him on the map,” although Haig has written seven other titles for adults and several successful children’s books.

Haig, Clare tells me, is an example of a writer whose career has grown steadily over the years, and with How to Stop Time he’s found “a fascinating central concept, a man destined to live a very long life over 400 years.” She adds that she “loved its readability, power, and depth, and ultimately its sense of hope and regeneration.”

This new novel, according to everyone I speak with, is poised to be big, and is likely to be his breakout book in the U.S. Back in the U.S. after Glastonbury, I call Cannongate publisher Jamie Byng, who is equally enthusiastic about Haig and How to Stop Time. Byng calls Haig a “dream writer” and says that “in my 23 years, I’ve never felt as confident about the commercial success of a book as I do about this one.” He compares How to Stop Time to Yann Martel’s Life of Pi, “the third book of a little-known Canadian with a first printing of 6,000.” And he quotes author Jeanette Winterson (Oranges Are Not the Only Fruit), who has said of Haig, “He uses words like a tinner... and we are the tin.”

When I ask Byng and others about the portability of a U.K. book to the U.S., there doesn’t seem to be any concern. The themes are universal: love and history and aging. And when I read How to Stop Time, I have to agree. The story moves back and forth hundreds of years between the present and the past, and around the globe, from London to L.A. to New York to Paris and “somewhere above Australia,” to name a few settings. It’s logical for the story to cover so much ground, since the narrator, Tom, was born “on the third of March in the year 1581.”

The opening line of the book is, “I am old.” And within this involving, expansive story there are wonderful observations about living such a long life. “It occurred to me that human beings didn’t live beyond a hundred because they simply weren’t up for it,” Tom notes. “You grew too bored of your own mind.”

And just when you’re nodding your head, a little depressed at the thought, Haig brings his character to the office of the doctor who first described progeria, the condition of premature aging, convinced he’s found someone who can help him with the problem of living endlessly. You’re also believing help is near, until the doctor’s taciturn suggestion that Tom should get himself immediately to Bethlem Hospital (the infamous Bedlam for the criminally insane).

We understand, though, that living 400 years is not easy. Our hero suffers from headaches: “And the memories break through like water bursting a dam. My head pulses with a pain even stronger than I’d had in the class earlier, and for a moment, in a lull between the sound of cars, I feel it, I feel the living history of the road, the residue of my own pain lingering in the air, and I feel as weak as I did in 1599, when I was still heading west, delirious and ready to be saved.”

Patrick Nolan, Haig’s U.S. editor at Viking, whom I talk with after Byng, tells me that he first met Haig as a sales director in the office of Kathryn Court (president and publisher of Penguin), and remembers thinking, “What a nice guy.” (I’ve heard this again and again, unprompted, from Clare, and Byng.) Nolan published Reasons to Stay Alive in the U.S. and calls that book “his passion project.”

“My first thought when I read it was that I had to publish it,” Nolan says, and he was pleased with the 20,000 in U.S. sales. He felt it was not only a wonderful book but one that could really help people.

Nolan is just as bullish on How to Stop Time. Again he felt that this was a book he had to publish. He sees How to Stop Time as “what you’d expect after the memoir,” adding: “All the realizations of the memoir are in the novel. What is the meaning of life? Of love? The story of the 400-year-old character is serious, but Haig handles it with a light touch.”

Nolan is excited by the in-house enthusiasm for How to Stop Time. The day of the sales conference, a week after the book launched in the U.K. on July 13, How to Stop Time hit #3 on the London Sunday Times hardcover fiction list. “And we’re publishing it here on Valentine’s Day, 2018,” Nolan says. “It’s a love story and we want to play that up.”

I am in concert with Haig’s fans as I read the book, turning pages for the story but also stopping to underline passages. I want to remember the lines. I want to read them out loud to someone. Nothing like a love that lasts 400 years.

Thinking back to Glastonbury, there was an amazing assortment of music and characters: Katie Perry, Bee Gees founder Barry Gibb, the Foo Fighters, and Johnny Depp (who arrived in a vintage baby blue Cadillac). I heard Turkish writer Elif Shafik—whose latest novel, Three Daughters of Eve, is being published in the U.S. by Bloomsbury in December—in conversation. And a first at this year’s festival was a bookstore on the fairway, set up by the Bath bookstore Mr. B’s Emporium of Reading Delights. On a recommendation I bought The Dig by Cynan Jones, a novel set in rural Wales about a sheep farmer and a badger baiter (we were in the U.K., after all).

And as to How to Stop Time is doing? After reaching #3 in its first week in the U.K., it was, according to Byng, “forced back to press three times” with 40,000 copies in print. As of this writing, the number has moved to 60,000. The book’s been optioned for film by Benedict Cumberbatch’s production company—he’d play the lead—with a budget of $25 million. A serendipitous beginning for a book discovered over a cup of tea.