By Anne Rivers Siddons

Harper & Row. 566 pp. $18.95

The bad news is "Peachtree Road" is not "Gone With the Wind II."

The good news is "Peachtree Road" is not "GWTW II."

Given a novel spanning four decades of Atlanta history and the lifetime of a willful belle, no publisher worth his salt could resist claiming descent from Margaret Mitchell's classic. But unlike the fierce, fragile women who move through the pages of "Peachtree Road," this book needs no exalted pedigree. Anne Rivers Siddons' fifth novel can and does stand on its own.

Readers of Siddons' earlier books will recognize the terrain -- a South caught between its gorgeous, if deadly, past and its bustling integrated future -- but she portrays it here with new coherence and force. The entire history of a time and place comes vibrantly alive in the person of a single woman.

In Atlanta, on the eve of World War II, breeding will out and family will rally round. When feckless James Bondurant abandons his wife and three children, his solid brother and socially impeccable sister-in-law take them in. Overnight, 5-year-old Lucy Bondurant goes from "white trash" to genteel, if unwelcome, poor relation in the patrician Bondurant household. And Sheppard Gibbs Bondurant III, her 7-year-old cousin, is transformed from a lonely only child who lies awake at night listening to his parents' unhappy coupling into one half of an unholy spiritual duo. Just as the South and its men have doomed Lucy, so she in turn will haunt Shep's life.

While the privileged youths of Atlanta dance their way through a gilded '50s adolescence, Lucy breaks social rules, courts sexual disaster, embraces the civil rights movement and, in her terrible, insatiable hunger, wrecks the lives of those she loves most. Lucy cuts a swath of destruction through Atlanta that would give Sherman pause.

Siddons knows her world. She brings home with sudden immediacy a rich white boy's stinging sense of insignificance when he first encounters his black counterparts fighting for equality. She sends up the Byzantine maneuvers of Southern women in their quest for social ascendancy. She celebrates the surface allure of a fast-fading way of life even as she probes the cancer at its core.

The strokes are often broad. Many of the characters are larger than life. Ben Cameron, the patrician mayor of Atlanta, his wife and his daughter Sarah are almost too good to be true. Lucy's mother is a beautiful monster, Shep's father an unassailable fortress. Passions burn impossibly hot. Shep claims a lifelong love for saintly Sarah Cameron, but chooses to consummate it only once. In two separate scenes, Atlanta and its aristocracy literally go up in flames. But the author never loses her sure hold on social customs and psychological truths, and is at her best dissecting them.

Unfortunately, the long novel occasionally sags under the weight of repetition and overwriting. We hear too often of the special magic of the Buckhead Boys, the power and probity of their fathers, the changing face of the city. Sarah Cameron never comes on stage without a reference to her alternately sherry or amber eyes and curly hair. A light of some sort always burns in Lucy's eyes. Frequently, the writing simply runs out of control. "It was our first taste of loss and inexorability, and we quivered with that promissory loss like violins tuned to infinity." In a review of an earlier Siddons novel, I wrote that her lush lyricism grows from the very soil of the South. At times, that lushness threatens to overrun "Peachtree Road," and the reader stumbles through a dense undergrowth of tangled images and adjectives.

The book is also a victim of some of the old prejudices it repudiates. The civil rights workers Lucy falls for are not ordinary grass-roots liberals but lapsed scions of old Southern families. Black retainers live only to serve and preserve the old order.

These are flaws of excess. "Peachtree Road" is a huge, sprawling novel. It is also a carefully wrought one that somehow manages to retain the grace and delicacy of the world it mourns. Most important, it is a compulsively readable book. Siddons is a born teller of tales. Just when we think we know the story of Lucy and Shep Bondurant, the author pulls us up with a double-twisted ending that recasts everything that has gone before. Like the gracious old houses that line it, Peachtree Road is a world we live in and carry with us long after we leave it.

The reviewer's new novel, "Looking for Love," will be published next year.