by ELLEN SCHWARTZ

Sallie Kincaid, the main character of Jeannette Walls' new novel, Hang the Moon, sees the contradictions in life. As she says, "Legal and illegal and right and wrong don't always line up. Sometimes the so-called law is nothing but the haves telling the have-nots to stay in their place."

The book, set in western Virginia during Prohibition, tells the saga of the scandal-ridden Kincaid family. For Sallie, helping her poverty-stricken neighbors bootleg moonshine whiskey, in defiance of the law, not only makes business sense—her family's general store relies on the revenue from selling the contraband—but is also a moral calling. As Walls explains, speaking from her home in Virginia, "Appalachia has mountainous, rocky terrain, ill-suited for growing agricultural crops. People would have starved to death if they hadn't made moonshine. Besides, my own father ran bootleg liquor."

Walls says she is fascinated by this era in American history. "It was a transitional period from an agrarian to a modern society. The automobile broadened people's lives, especially those of women, offering greater freedom. Two amendments to the Constitution—one outlawing alcohol and the other giving women [the right to] vote—occurred simultaneously. This was a complex, contradictory time, and I liked that."

Walls' own life in some ways echoes that of her protagonist. Her family moved often during Walls' childhood and experienced periods of homelessness. When they finally landed in rural Virginia, they lived in a three-room house without plumbing or heat. "I'll never forget when we first got electricity," Walls says, her voice full of wonder.

She captured this time in her 2005 bestselling memoir, The Glass Castle. The book has sold more than 5 million copies, has been translated into 31 languages, has received numerous awards and was made into a 2017 film starring Brie Larson and Woody Harrelson. Walls has also published two previous novels, Half Broke Horses: A True-Life Novel, based on the life of her grandmother, and The Silver Star.

"I'm drawn to stories about women who make their own way," Walls says. "In the early 20th century, women were gaining more independence, but there was also massive pushback. When I was doing research, I was appalled at the dismissal of women in popular culture, even downright hostility. They were being told to go back into the kitchen after having held down jobs and supported their families during World War I. I wanted to create a tough, feisty character in Sallie who could rise above all that."

When asked about the difference between writing fiction and nonfiction, Walls replies, "With nonfiction, you're writing about things that have happened. Writing fiction is like standing in the middle of the ocean. You can go in any direction. It can be overwhelming." To achieve realism, she continually asked herself, "Could this have happened. Is it plausible?"

Walls typically writes four to five hours daily, sometimes turning out 20 pages a day. "But then I rewrite. When I read something back and it doesn't sound right, I know I haven't gone deep enough. I love problem-solving, that euphoric feeling when I figure out how to make it work."