When I tell Donald McCaig that I expected to dislike his sequel to “Gone With the Wind,” his laugh is a quiet roar. “I don’t think most rational people expected to like it,” he says.

But when St. Martin’s Press executive editor Hope Dellon happened upon McCaig’s Civil War novel, “Jacob’s Ladder,” in a bookstore, she knew he was the right voice to add to Margaret Mitchell’s canon.

“Rhett Butler’s People” is the result of that 12-year quest, a quest for which St. Martin’s gambled $4.5 million when it paid the Mitchell estate for the right to publish a second sequel. But until he was asked to write it, McCaig, a Montana-born sheep farmer living in the mountains of western Virginia, had never read “Gone With the Wind.” Until this summer, neither had I.

I’d always assumed that Mitchell’s thousand-page Confederate saga would be a dull and melodramatic bodice-ripper, so I was surprised to find true despair, passion, wit and fervor in the lives of Scarlett and Rhett — and equally so in the life of their author. Mitchell’s biography reads like her fiction: A rabble-rouser, a renegade and a beautiful woman torn between two loves, she was an intense, hilarious and often deeply troubled writer whose life ended in 1949 when she was hit by a car.

Many have wondered how a sequel could improve upon the 1936 Pulitzer Prize-winner. McCaig warned his editor about the very real possibility of negative reviews. But by and large, the opposite has occurred. Already in its second printing, “Rhett Butler’s People” has far exceeded expectations, reports Steve Troha, associate director of publicity at St. Martin’s Press. “The Mitchell estate is very happy,” he says. “They love it.”

The project was a bear, McCaig says: “The two books had to mesh impeccably. Some people know that book like the preacher knows the Bible. And it had to be historically accurate for all the Civil War buffs out there.”

To re-create the time line, McCaig’s wife created a chapter outline, 120 pages long, and McCaig tracked three concurrent chronologies: the original story, Rhett’s story and history. Each had a different typeface. He says the most difficult scenes to write were the ones that Mitchell had already written, but it wasn’t difficult to add dimensions to the characters. “I thought about real people, how they would behave,” he says. “I do not know two women in the world whose best friends are eager to snatch up their husbands and they do not know it. Fifteen minutes and one little lingering glance. Are you crazy?”

Unlike the first sequel, Alexandra Ripley’s “Scarlett,” McCaig’s book doesn’t try to re-create Mitchell’s voice, or in the case of race and slavery, her beliefs. “I’m a Southern writer of our time,” he says. “She was a Southern writer of her time. Mitchell is very curious because of her bad racial attitudes but good African-American characters. They’re often more enlightened than their white counterparts. It would be repellent to re-create those attitudes.”

His impression of her work? “It is in part brilliant,” he says. “I think Mitchell’s prose was florid, overblown and enormously effective. It’s about 150 pages too long. I just flipped through the dithering over Ashley. What I thought was the best writing in the book was when Scarlett was trying to hold everything together after the war. I thought that was brilliant.”

By contrast, McCaig’s prose is manly and poetic. The story is crafted with complexity and thoughtfulness, the racial issues handled with equanimity. Many of the characters have gained a dimension.

When I ask about Mitchell’s ardent desire for her ending to remain intact and her refusal to appease the masses who begged her for resolution, McCaig does not hedge: “If there’s one question that everyone asks about the original, then a writer doing a book like mine has to answer that question. Part of what made that possible was forgetting that these characters are icons. If these were real people just like my friends, what would happen next? I mean, what would really happen?

“I answered that question.” S

Donald McCaig will be at the Library of Virginia at 800 E. Broad St. Monday, Nov. 26, at 6 p.m., to read and discuss “Rhett Butler’s People.” Free parking is available under the building. 692-3900.