The best novels tell stories that matter with perfect credibility. Isabel Allende’s latest effort, “Ines of My Soul,” is compelling and ambitious in scope. But it was not believable enough for me.

It is very seldom that the story of the brutal era of colonial 15th century South America and its conquistadors is told without guilt. It is very seldom that the story of conquest is anything but a cautionary tale of blood and calamity. But in this novel, the narrator Ines Suarez describes the conquest of Chile as a success.

I was not convinced.

Personally, I find this sort of borderland-epic concept compelling enough to justify reading 300-page novels written by authors much less talented than Allende. It is the frontier story; the tale of the Old West. The story is supposed to create a world in which human nature can be explored outside of the rules constructed by civilization as we know it.

But despite the novel’s thematic landscape, I found myself approaching the book skeptically, suspiciously analyzing the account of an inconsistent protagonist who seemed too willing to invoke spirituality whenever it suited her. She obtained power through her lover but refused to act as though she had any influence over him. She seemed duplicitous.

Like the vast majority of Allende’s protagonists, Ines was a spirited woman who was steeped in heritage and folklore. She had to act like the community magician. She saved men from dying of thirst in the Atacama Desert. But unlike some of Allende’s prior heroines, Ines is not a mystic. When she sees ghosts, when she claims that skeletons walk in the darkness, she does not seem credible. She is far too pragmatic a person.

The novel is written as the fictional memoir of the 70-year-old Ines. She is a conquistador’s concubine and governor’s wife who describes her life to an adopted daughter, Isabel. Her narrative is fast-paced but punctuated with sentences that remind the audience that the events being told have already happened. The story has a palpable sense of history and heritage. Ines’ story is important because she was the governor’s wife, and a member of the expedition that first journeyed from Cuzco to Santiago.

From the very beginning, the audience is aware that Ines’ most important relationship is destined to fail. For a reason that is at first kept secret, Ines does not stay with the conquistador Pedro de Valdivia. Instead, she marries his subordinate, the captain Rodrigo de Quiroga, who later becomes the governor of Chile.

Ines’ life is narrated as if it is always in motion. She first travels from Spain to the New World, where she eventually winds up in Peru under Francisco Pizarro. There, she meets Valdivia, and joins his expedition to settle the land of Chile. She narrates the expedition’s journey from Cuzco to Santiago.

Her life’s story is about both war and civilization. The foundation of Chile was at the expense of the Mapuche, just as the foundation of Peru was at the expense of the Incas. But to Ines, the war and the sacrifice are worthwhile. Chile, to her, is paradise.

But Allende points out that a place like Chile can be heaven and hell simultaneously.

“[The New World] is paradise only in appearance,” Ines is cautioned. “In a hot, swampy, voracious world infested with reptiles and poisonous insects, things decay very quickly, especially the soul. The jungle transforms men into rogues and murderers.”

Thematically, the novel is well-realized. Allende forces the reader to think about the unanticipated consequences of war. Blood and guts are present and accounted for in Ines’ world.

But Ines is not herself a conquistador; she was simply in love with one. The novel is therefore unusual in its tendency to stray from the conquest narrative. Ines describes herself as a civilizer. She speaks of “founding” Chile as something separate from conquering or claiming. She speaks of building hospitals and churches, of coordinating the planting of Santiago’s first harvest.

But although Allende doubtless intended Ines to seem noble, the great Founding Mother of Chile, her character is too inconsistent to be so worthy of respect and trust. She does not transport the reader to another time and place. Her superstitions seem silly and ill-considered, as do some of her ethical decisions.

Allende’s earlier effort “The House of the Spirit” has been one of my favorites since I read it in high school, but its triumph was the simple truth of the most outlandish of its claims. “Ines of My Soul” lost my interest halfway through. I could not tell whether Allende had meant Ines to seem duplicitous, or if that trait was my own paranoid invention.

The reader’s lack of faith in Ines’ intentions is why I think this novel fails.