In September, Knopf will publish Jayne Anne Phillips’s new novel, Night Watch. It’s been a decade since her last novel, Quiet Dell, and years since her debut, the story collection Black Tickets, which Seymour Lawrence published at Dell in 1979 to rave reviews when the author was in her 20s. The promise of that first book has been fulfilled with every subsequent book, and Phillips just keeps pushing the envelope and getting better and better.

Night Watch, Knopf’s Ann Close writes in her introductory editor’s letter, is the last in a trilogy of war novels, beginning with Machine Dreams (1984), about the Vietnam generation; followed by Lark and Termite (2008), about Korea; and now Night Watch, set in the aftermath of the Civil War. The story opens in 1874 West Virginia, nine years after the war ended. Phillips says she often begins her books with a mysterious scene, and these first paragraphs are not only mysterious but foreboding, with 12-year-old ConaLee climbing into a wagon. She’s told to sit there next to her mother by a man called Papa. Phillips writes: “Hold her hand there, he said to me, like she likes. Sit tight in. Keep her still. I saw him lean down and rope her ankle to his. I was warm because he made me wear my bonnet, to keep my skin fine and my eyes from crinkling at the corners. In case someday I turned out after all.”

“Writing about war has always been a fascination for me,” Phillips tells me. “In the Civil War, the country was divided, and also today the climate is the estrangement of people, the political divide. I wanted to give a vivid sense of what was happening after the Civil War. The influences, the why of these relationships and how they were created. In this opening, a child is frightened that this man, Papa, is going to separate her from her mother.”

ConaLee’s father has disappeared and Papa, a war veteran, has insinuated himself into the lives of mother and daughter, sexually using and serially impregnating ConaLee’s mother, Eliza, who has been mute for a year. Now his plan is to take them away from their home and all they know (including the children he fathered) and to leave them at the Trans-Alleghany Lunatic Asylum in West Virginia. Phillips writes: “He leaned down and pointed a finger at me until he touched my throat, just at the little notch of bone. Then listen, he said. I am not your Papa, nor have I ever been. I never laid eyes on you or your mama till I came upon you, and you don’t know my name.”

Papa instructs ConaLee to pretend to be her mother’s servant so she can stay with her at the asylum, and to say that this man picked them up on the road and “rode you here as a kindness.” As the story progresses, readers learn the backstory and also watch ConaLee and her mother rebuild their lives at the asylum with a bevy of characters, including the doctor who runs the institution.

Phillips wants the reader to “understand the history of another time, to appreciate it—and the best way to understand,” she says, “is fiction. I want to write scenes where the reader can feel the shattering moments.”

Here Phillips describes battle: “That torturous field!” she writes. “A soldier... took a shell to the gut and rose whirling into the air, flung star-splayed as though before a revelation. The explosion rained down bits of flesh and bowel and bloody entrails on those below; the body dropped to the ground like a bag of wet sand.”

And when Eliza is raped by a marauding soldier after hiding ConaLee: “Oh, yes, I saw you run with her, drop her in. We been routing folks out of root cellars, North and South, taking their precious. But I ain’t in the market for no kid. You’ll do what I say. You’ll give it up. Say so.” What follows is terrifying, graphic, heartbreaking, as the soldier not only rapes her but taunts and humiliates her.

The Civil War, Phillips says, obliterated so many lives. “I wanted the book to reflect displaced populations, to show the spectacular losses in times of chaos and for readers to feel the connection to history which we are doomed to repeat.” She explains that while history gives us the facts, “literature tells us the story. Story helps us approach a life experience from which we are estranged. Literature can penetrate.”

Lynn Nesbit, Phillips’s agent at Janklow & Nesbit, tells me the contract for Night Watch was based on a few pages. “Jayne Anne writes beautiful lines of description,” she says. “This book has such a strong story line. Between her use of language and the compelling plot, it’s a twofer.” She read pieces early on, but when she saw the draft a year ago, she says,“I couldn’t stop reading.”

Nesbit doesn’t remember how she came to be Phillips’s agent and advises me to ask the author. Phillips does remember: “I was at the St. Lawrence Writers Conference and Seymour Lawrence was there—to recruit Peggy Atwood, although he didn’t. I had a chapbook published with Truck Press and gave it to him. My parents’ wedding picture was the cover. I was 27, just out of grad school at Iowa. He asked me to send him my stories, and that was the start with Black Tickets. I signed a contract but had no agent, and he told me, ‘Call Lynn Nesbit. She’s the only agent I’m afraid of.’ Lynn and I have been together ever since.”

Close has been Phillips’s editor for 20 years. She also saw Night Watch in pieces. “Jayne Anne likes to get feedback, and I like that too,” she says. “She’s always wonderful, always interesting, and it’s fascinating to be in on the changes, to watch a talented writer work. It’s a gift. I’ve learned a lot seeing the books develop. I’ve always felt blessed to have her as one of my writers. She’s written amazing, major books and this one is absolutely her best. The Civil War is always thought provoking and this book has powerful scenes and powerful characters. Jayne Anne has such a range of imagination: she writes about war and then inhabits the mind of a child with total believability.”

Night Watch took time to write. The contract was signed on Dec. 16, 2015. “I’m not usually quick,” Phillips admits, “but I was working full time. No writer wants a contract hanging over their head, but for me it was helpful. The writer’s life is the secret life that gets pushed aside.”

The book also involved lots of research. “I wanted a sense of the time period,” she says. “I have shelves of books, diaries, accounts. The story and characters are imagined but the reality they lived is real, which is why I have images in the book. Also, the asylum is a real place [now abandoned] near where I grew up.”

“I like to live with a book,” Phillips tells me. “It’s a test if it’s compelling enough to stay with five, six, seven years.”

I ask if she felt pressured to finish. “Well,” she says, “they would ask, ‘How’s the book?’ ”