"The Covenant of Water" is a sweeping, 715-page, 10-part, 84-chapter novel that spans three generations. But it started with a simpler tale, told in a school notebook.

Author Abraham Verghese's 5-year-old niece had asked his mother, then in her 70s, about her life as a girl. So she wrote, in "the most elegant script," the story of her life, which began in Kerala, a Christian community on India's coast. She sketched it, too.

"She wasn't doing this for posterity," he said by phone in August, ahead of his Talking Volumes appearance Sept. 14. "She was doing this for my niece."

Verghese, 68, had been aware of the document's existence for some time. But it wasn't until completing his 2009 novel "Cutting for Stone" that the doctor-turned-writer saw in it a setting, a family and, eventually, a story.

That first novel, about twin brothers raised in the shadow of the Ethiopian revolution who become surgeons, drew on Verghese's other career, which he continues — quite successfully — even amid a film adaptation and an Oprah anointing. "The Covenant of Water," too, features plenty of physicians, maladies and surgeries. Its central mystery is medical.

But the multigenerational saga centers its mothers and grandmothers, who resemble Verghese's own.

"My mom was a pretty amazing woman," he said. Mariam Verghese graduated from college in the 1940s, when the British were leaving India and jobs were scarce. So she answered an ad for a teaching position in Ethiopia. "You just have to picture this single woman in a sari heading off to Africa by steamer.

"It's hard to imagine how brave you'd have to be."

A book brought Verghese to medicine: "Of Human Bondage," a 1915 novel by W. Somerset Maugham, drew a portrait of "humanity there in the rough," inspiring him to become a doctor. Practicing medicine, in turn, inspired him to become a writer.

An infectious disease specialist, he took a job in rural Tennessee in the 1980s. Although HIV/AIDS was then considered to be an urban condition, he said, he was soon treating 100 patients with the virus in a town of 50,000.

He detailed the phenomenon in a scientific paper. "But that didn't quite capture the heartache," he said.

His patients had led "incredibly rich lives compared to mine — and mine had covered a couple continents by then — in terms of the breadth of their interests and the way they put their minds to exploring the world," he continued. "I took to heart the lesson, which was, 'Don't postpone your dreams.'"

So in 1989, his spirit strained, his marriage suffering, he and his family moved to Iowa, where he was accepted in the University of Iowa Writers' Workshop. There, while moonlighting as a doctor, he became close with acclaimed author John Irving, met his longtime agent and published a short story in the New Yorker.

Working at a hospital in El Paso, Texas, he woke at 4:30 each morning to finish what would become the graceful memoir "My Own Country: A Doctor's Story of a Town and Its People in the Age of AIDS." (One of his very first book readings was at the legendary, now-defunct Hungry Mind in St. Paul: "I remember being blown away by the store.")

Verghese still practices medicine. "I never considered not doing so," he said, simply.

As the vice chair of the Department of Medicine at the Stanford University School of Medicine, much of his work these days is administrative. But he still teaches, still works with residents, still sees patients.

He writes at night, on weekends and between meetings at Stanford "in a secret office with someone else's name on it."

So he takes his time, completing pages at a pace that he called "ridiculous." Joyce Carol Oates, he guessed, has written 56 novels — actually, 58 — dozens of plays and a bunch of children's books. "She's probably written a book since breakfast."

The epic "The Covenant of Water" took him more than a decade. He sketched the novel's timeline, characters and intersections on a white board in his living room, creating a colorful, intricate web of phrases, faces and exclamation points.

But it begins simply, with the character who came to him first: a 12-year-old girl on her wedding day.

She lives in South India, on the Malabar Coast, in "a child's fantasy world of rivulets and canals, a latticework of lakes and lagoons, a maze of backwaters and bottle-green lotus ponds; a vast circulatory system because, as her father used to say, all water is connected." But the young bride's new home, an estate called Parambil, is set far from the shore.

"Why here?" she wonders. A curse, she discovers, which she dubs "the Condition." Drownings, often in ditches or other shallow waters, have stricken every generation of her husband's family.

Over the course of the novel, it becomes clear that the curse is a medical condition, one that a young, enterprising doctor named Mariamma, granddaughter of that young bride, aims to cure.

"As a longtime teacher of medicine, I keep in my back pocket ... a whole collection of riddles and rare diseases," Verghese said, that he uses to quiz residents during dull moments. "I've always marveled at how the sweep of medicine is such that very often there's something that we observe — but we don't know what it is. Then, sometimes decades and lifetimes later, the mystery is unraveled. And then eventually, the molecular basis is understood.

"And then eventually, it becomes almost a thing of the past."

Reviewers have occasionally dinged Verghase for his medical detailedness. "One would, I suppose, be ill-advised to use this novel as a textbook for liver transplantation or bowel surgery," the New York Times wrote of his debut novel, "but it might almost be possible."

But he doesn't apologize for drawing on what he knows. "What is medicine but life-plus-plus — life on steroids?" he said. "It's not as extraneous as if I was, I don't know, a nuclear physicist."

The book contains far more than medical minutiae. Tucked within his new novel's pages are beliefs Verghese has formed over a lifetime beside patients. That a physician ought to learn how to change a bedridden patient's soiled sheets. That technology can't capture what an old-fashioned physical exam can.

Being a physician taught him to examine the body, to mine it for clues. Writing, in turn, helps him make sense of medicine's profound experiences.

"I am intrigued by humanity, by the human body, by people in their complexity," he said. "How much of that is physician-hood? How much of that is being a writer?

"It's hard for me to tell anymore."

'The Covenant of Water'
By: Abraham Verghese.
Publisher: Grove Press, 736 pages, $30.
Event: Talking Volumes, 7 p.m. Thursday, Sept. 14; Fitzgerald Theater, 10 E. Exchange St., St. Paul; $28-$30.