Caleb’s Crossing, By Geraldine Brooks, Viking, 2011, Hardcover, 320 Pages, $26.95, in bookstores May 3.

Caleb’s Crossing> is a work of fiction based on one largely unknown piece of 17th century Martha’s Vineyard history. In an author’s note, Pulitzer Prize-winning novelist and Vineyard resident Geraldine Brooks writes that the book is “a work of imagination, inspired by the life of Caleb Cheeshahteaumauck, a member of the Wôpanâak tribe of Noepe (Martha’s Vineyard), born circa 1646, and the first Native American to graduate from Harvard College. The character of Caleb as portrayed in this novel is, in every way, a work of fiction.”

Little is known of the life of Caleb Cheeshahteaumauck. To take the scratches of documented information of his life and mold them into a tale narrated by a young, white, Christian female member the Island’s first English settlement is a bold move.

The narrator in Caleb’s Crossing is Bethia Mayfield, daughter of the new settlement’s minister, a man set about to save the damned souls of Martha’s Vineyard’s native population. He tells Bethia that “God in his wisdom has not done so much for these as He has for our nation. Satan has had full charge of them.”

Bethia is a strong, smart and capable girl ensconced in a sexist and rigidly religious society. At age 12 she develops a secret friendship with Caleb, an equally intelligent and inquisitive young Wampanoag, son of a chief and nephew of a powerful healer.

At first their friendship is defined by the world around them, the unfettered bounty of the Island in the mid 1600s.

“ . . . I followed that feathered head through eel grass and over sandy dune, to clay pit and to kettle pond . . . He walked through the woods like a young Adam, naming creation. I learned to shape my mouth to the words — sasumuneash for cranberry, tunockuquas for frog. So many things grew and lived here that were strange to us, because they had not been in England . . . So when he named a plant or a creature, I felt that I had heard the true name of the thing for the first time.”

When Caleb tells her how Moshup created the Island she “thought it all outlandish. But as I rode home that afternoon, it came to me that our story of a burning bush and a parted sea might also seem fabulous, to one not raised up knowing it was true.”

Bethia is crushed when her father suddenly cuts off her formal education. Proper versing in catechism, he tells her, is all a girl need know. Salt to the wound, he continues grooming her lazy brother for Harvard College. Bethia makes the best of this hurtful turn of events:

“Over time, while my father thought I was tending the cook fire or working on the loom, I shored up my little foundations of knowledge: some Latin here, some Hebrew there, some logic and some rhetoric.”

Caleb’s world is also in flux. He is deeply honored to be mentored by his uncle to be a healer, or pawaaw. Yet his joy is tempered by the new settlers’ quest to undermine the spiritual authority of the Wampanoag healers. When strange diseases infect the Wampanoag people it seems that only the power of the English God can heal them. Young Caleb’s faith is shaken.

Bethia introduces him to the English language, both the spoken and written word: “This was the first book he had held in his hand.”

“‘These snowshoe tracks,” he said. “They speak to you?”’

“I explained to him that the letters were a kind of code, like the patterns worked into the wampum belts the sonquems wore, that told some kind of abbreviated history of his tribe.” Caleb agrees to let Bethia “teach me this book of yours.”

Despite the cultural and spiritual divide, Bethia and Caleb are, in many ways, kindred souls. Quick-witted and adventurous, both are curious but wary of the other’s world. Both are marginalized by the white world, she by sex and he by race. And both have a deep thirst for learning. But Caleb’s Crossing is not an equal opportunity telling of events. It is Bethia’s strong story, her compelling coming-of-age, her world view, and her pain and prejudice that streaks across the page:

“It had been instilled in me often enough that preaching was not women’s work . . . And yet how could I turn my back on a soul that might be saved? . . . Perhaps, I thought, if I could teach this boy — son of a chief, apprentice to a wizard — bring him to father as a convert, versed in scripture — father might see the worth in me, and consent to instruct me again, in those higher learnings that he labored over with my dull-witted brother.”

An exceptional student, Caleb is taken in by Bethia’s father to be prepared for Harvard College. “It seems the college,” Bethia explains, “had built a second house there, alongside the English one, exactly for the education of Indian youths, with the aim to make them instruments for the propagation of the Gospel among the tribes.”

Less clear, naturally, is Caleb’s motivation for pursuing an English education. He is a very young man — a boy, really — being pushed and pulled between two conflicting worlds. Every choice he makes is bound to hurt people he loves. How interesting it would be to understand his Wampanoag upbringing, to learn the ways of the pawaaw, to see inside his heart.

With Bethia, a narrator compelled to set down her “spiritual diary,” Ms. Brooks has created a rich character — thoughtful, witty and convincingly wise beyond her years. Bethia yearns for a proper education, a bigger world upon which to chew. She is scarred by loss, bound from the larger world by water, and deeply stifled by the strict conformity of her religious upbringing. And as devoted as she is to her true friend Caleb, she is often unable to shake her deepest spiritual fears.

While he studies in Cambridge she finds herself wondering if he is “a vessel through which darkness yet trickled, a conduit that might carry the taint of evil into God’s own churches . . . ? Of course it was not so. These morbid imaginings sprang from exhaustion, merely. Yet tears filled my eyes . . . ”

This is a thoroughly Vineyard book. The author, Ms. Brooks, lives in West Tisbury. The cover art for the book is a photograph by William Waterway of Edgartown.

The clash of cultures that drives the story is all too familiar today, 350-odd years later. Native Americans are still subjected to racism, women to sexism. Religious intolerance remains rampant. Piety and self-righteousness rule the airwaves. When we fail to heed it, history tends to trail us.

Yet the overriding themes that run through Caleb’s Crossing are those of love, courage and fortitude. The writing is exquisite and the Island plays a leading role. Here Bethia describes the world outside her door after a wild storm:

“The sea was pewter, and the wrack line stood high upon the strand, even to where the first low scrub oaks struggled for their spindly lives like aged and bent-back crones.”

And after a long winter: “The Lord’s Day when Caleb finally came to us was bright and glistening. It was one of those days in early March that tease the senses, promising Spring when in fact much bone cracking weather must yet be endured.”

Early on in her narration Bethia sets the stage for that most important of questions — the one based on the book’s title. Put simply, too simply, did Caleb “cross”?

“Caleb’s soul is stretched like the rope in a tug o’ war, between my father and his own uncle, the pawaaw. Just as my father has his hopes, so too does that sorcerer. Caleb will lead his people, I am sure of it. But in which direction? Of that, I am not in the least bit certain.”