The opening scenes of Michael Crummey’s engrossing and beautifully written new novel, “The Innocents,” are as bleak as any work of fiction I can think of. “They lost their baby sister before the first snowfall. Their mother . . . was deathly sick herself by then, coughing up clots of blood into her hands.” The “they” here are a pair of siblings, Evered and Ada Best, 11 and 9 years old, respectively. Before the New Year, they will be orphans as both of their parents succumb to the mother’s illness. Those losses are especially daunting given the novel’s setting — a remote cove on the northern shore of Newfoundland sometime in the early 19th century.

The Bests are tenant farmers and fishermen. Twice a year a sailing ship, the Hope, drops anchor in the cove to deliver supplies and collect the season’s catch of salted cod. It is their only connection to the rest of the world. As young Evered soon learns, they are in a vicious cycle of debt to their absentee landlord, Mr. Strapp. Strapp’s agent, Mr. Clinch tries to convince them to abandon their life in the wild, but Ada and Evered stubbornly remain. Life beyond the cove is simply unimaginable.

The day after he buries his father at sea, young Evered wakes up to discover that his hair has turned completely white. This is the first of many transformations the youngsters will undergo. As the book’s title suggests, Ada and Evered are a New World Adam and Eve, and Newfoundland is a harsh Garden of Eden. “The Innocents” is a tale of survival but also a story about the acquisition of adult knowledge. In place of the serpent and forbidden fruit, Ada and Evered have curiosity, need and desire.

“The Innocents” is a work of lyrical naturalism dressed as an allegory. Crummey isn’t interested in chronicling his characters’ journey to spiritual salvation. Religion is repeatedly rejected in the novel. Evered declines an offer to be baptized by Mr. Clinch and only grudgingly permits an after-the-fact funeral for his parents. For the orphans, the celestial realm is “dry goods and flour and salt meat and tea.” Their quest is not a search for divine grace, but the slow and arduous acquisition of the skills and habits that will allow them to eke out an existence in this hardscrabble place.

Some of the best scenes in the novel are its descriptions of failures, deprivations and frustrations. Out in his boat, fishing for cod, Evered recalls his father’s talent for drawing an entire school of fish from the depths to the surface. Evered’s inability to do so makes him feel “that he was only playing at being a man.” During one especially hard winter, the pair are so malnourished that their gums go “grey and spongy,” their teeth loose enough that “they could work them like hinges with their tongues.”

Crummey’s book is built around the “severe round” of the seasons. Again and again we see the sequence: seal hunting, cod fishing and curing, planting and harvesting the vegetable garden, berry picking, jam making and then the long dark of the northern winter. This cycle is interrupted on a couple of occasions by unexpected visitors — sailors, explorers and adventurers. These galvanizing emissaries from the outside world disrupt the siblings’ settled solitude, bringing welcome company, but also making them question their lives together. “Each in their own way was beginning to doubt their pairing was requisite to what they might want from life.”

Another troubling visitor, brought by adolescence, is sexual desire. Neither knows what to do with their yearnings. “It felt halfway familiar and altogether new to the world,” thinks Ada. “It entered their lives like a third creature with its own being and sentience.” Crummey movingly renders the furtive, helpless complexities of Ada and Evered’s incestuous explorations. Ada is especially wary of the compromises involved. “It made her think there was no indulgence in the world that wasn’t cut with regret.”

While there are allusions to a fratricidal Cane-and-Abel event in the Bests’ family history, the original sin in “The Innocents” is the decimation of the native inhabitants of Newfoundland on whose land Ada and Evered try to survive. Against her brother’s wishes, Ada steals a pendant from an Indian grave. By the end of the book, it comes to represent the terrible knowledge that accompanies the siblings’ loss of innocence. “She regretted wanting it in the first place and loved it with all her heart still. She knew now that it was only herself she’d been lying to . . . Pleasure and shame. Shame and pleasure. These were the world’s currencies. And it paid out both in equal measure.”

Jon Michaud is the author of the novel “When Tito Loved Clara.”

THE INNOCENTS

By Michael Crummey

Doubleday. 304pp. $26.95