Seven pages into Pat Conroy’s new memoir, his father erupts into a rage because Pat’s mother has asked that he sing “Happy Birthday” to their 9-year-old daughter. After watching his mother backhanded to the floor, Pat, then a seventh-grader, tries to intervene, only to end up smacked to the floor with her.

“When I got between them again, there was very little room for all three of us as I pounded my fists against Dad’s chest before he slapped me out of the kitchen with his right hand. Somehow, I got the feeling during those years that my mother’s love for me depended on how many times I placed myself between them when Dad was beating her.” After that day, Conroy writes, he can’t remember “the next year of my life.” But he’ll spend the next four decades reliving versions of that scene and its aftermath in every book he writes.

His childhood, he admits, “is both the wound and the foundation of my work.” Pick up any of Conroy’s novels – “The Prince of Tides,” “Beach Music,” “South of Broad” – and you’ll find “disguised voyages” into the turbulent world he grew up in as the oldest child of Donald Patrick Conroy and Frances Dorothy “Peg” Peek.

In the prologue to “The Death of Santini: The Story of A Father and His Son,” Conroy promises that this journey will be his last. It’s easy to see why. Though the memoir covers much the same territory found in his books, it’s polished up, filled out and honed to a sharper point, a “reckoning” that presents a more damning and far-reaching indictment of the Conroy clan than anything found in his novels.

For those unfamiliar with his story, the blustering, sadistic hero of Conroy’s first novel, “The Great Santini,” was modeled on Pat’s father, a Marine Corps fighter pilot and veteran of three wars, hot-tempered and quick with his fists. He beat his five sons on a regular basis, as well as his wife, Peg, who eventually elected Pat to protect her and the other kids.

But it wasn’t enough to prevent the “ruthless collateral damage” that left two of Pat’s siblings battling mental illness and drove one to suicide.

When Conroy finally “let the hate out into the sunshine” in 1976, the truth-telling in “Santini” threatened to end his relationship with his father for all time.

Instead, a strange thing happened. When the family threatened to disown Pat for going public with their family hell, Don underwent a change of heart. He championed his son, making light of his savage portrait and attending Pat’s book signings. Though his father’s about-face is the centerpiece of “The Death of Santini,” it also functions as a springboard for Conroy to “examine the wreckage one last time.” Beginning with his high school graduation in 1963, the book chronologically recaps Conroy’s life via schooling, book publications and film adaptations, marriages, and the illnesses and deaths of his parents.

We’re introduced to his father’s side of the family, the “Chicago Irish,” a hilariously nasty group who clearly helped forge Donald’s abusive character. A look at his mother’s primitive Baptist background contributes to our understanding of her side of the equation, and of why the damage she inflicted, while subtler, was just as scarring.

Despite the intended “love story” he proposes to tell, Conroy can’t resist painting his family members as monsters. The adored sister Carol, on more than one occasion, delivers a performance of such bloviating self-importance and sustained venom that it’s hard to tell what Conroy’s after – the reckoning he promised or an exorcism.

But when he transforms his demons back into human beings, it’s impossible not to melt a little. Observe Don’s initial reaction, on the day he first sets eyes on the book that will flay him alive: “‘My God, son,’ he cries. ‘You’ve named the book after me. What an honor.’… He opened the book and started thumbing his way through its pages, excitable and happy-faced as a King Charles pup.” Like the rest of his mythic cast, Conroy himself plays dual roles in the book, wearing the same compassionate, affectionate disguise he often adopts in his novels – but missing not one detail of Mom or Dad’s scales, claws and slavering jaws.

The result is a heady, irresistible confusion of love and hate, “one more night flight into the immortal darkness to study that house of pain one more time,” to prove how low his princes and princesses of Tides can sink and how high they can soar.

True Conroy fans wouldn’t have it any other way.