The novel opens in January 1798 in Halifax County Court, Nova Scotia, where a young woman waits on the public benches as an accused woman is brought into the dock with red welts on her wrists. Their eyes meet with desperate intensity, establishing a bond whose fate drives the narrative. The story then moves backward to trace how these two women arrived at this moment.
In the winter of 1796–97, Cora, a young Black woman from Jamaica, navigates the hostile port city of Halifax in search of flour. She identifies herself to a suspicious white inspector as a Maroon, a member of a free Jamaican community exiled to Nova Scotia after losing a war against the British. Despite promises they could remain on the island, the Maroons were shipped across the ocean. Consumed by homesickness, Cora returns empty-handed to the settlement of Preston, where she shares a hut with Leah, a formerly enslaved woman who raised her; Silas, a Maroon captain and widower; and little Benjamin, Silas's young son. Cora has served as Benjamin's surrogate mother since the death of his mother, Elsy, Cora's closest friend. Elsy died of illness during the war while Cora was away foraging, and Cora carries deep guilt for having left her side.
Lost on a forest shortcut during the first snowfall, Cora spots a dark shape moving across a frozen lake and flees. She collides with an ox and meets its keeper, Thursday, a Black man who works under an indenture contract, a form of bound labor, for a white farmer named Nash. Thursday warns her to stay off the woodland paths. Back in Preston, tensions simmer: Silas, increasingly volatile, pressures Leah to arrange a marriage between himself and Cora, while little Benjamin whispers that he saw his dead mother in the trees.
After a neighbor's young son named Godwin goes missing in a blizzard and is found dead of exposure, Cora visits Thursday at Nash's farm. Thursday shares his own history: Enslaved in Virginia, he escaped with his mother, Efe, to the British lines during the American Revolutionary War. In Nova Scotia, Efe signed an indenture she believed was for five years, but because she could not read, the contract said twenty. When the chance arose to emigrate to Freetown, a settlement for free Black people in Sierra Leone, Efe was terminally ill. Thursday assumed the remaining years of her contract so she could sail to Africa and die in her homeland.
On the road home, Cora follows tracks in the snow to a freshly killed moose and discovers a young Black woman living alone in the forest with a gray dog. The stranger, armed with a bow, threatens to shoot but eventually lowers her weapon and directs Cora toward Preston.
In spring, Cora returns to the forest and locates the young woman again. She gives her name as Agnes and introduces her dog, Patience. Agnes confirms she has been watching Cora all winter: She was the mysterious shape on the ice. Over the following weeks, Cora visits repeatedly, learning to forage and read animal tracks. Agnes mentions the Mi'kmaq, Indigenous people who taught her survival skills, but deflects questions about her past. In their growing closeness, Cora experiences a quiet revelation, recognizing her feelings for Agnes.
In June, the conflict with Silas erupts after a dance at the governor's estate. Drunk, he tells Cora that Elsy warned him about her selfishness. Cora fires back that his war killed Elsy, and Silas strikes her across the face. She flees to Agnes's camp. Over the summer, Agnes takes Cora out in a birchbark canoe to witness humpback whales breaching. Cora becomes acutely aware of every touch between them. When little Benjamin follows Cora into the forest and discovers Agnes, he briefly mistakes her for his dead mother. Later, as Agnes walks Cora partway home, a butterfly lands on Cora's cheek and Agnes leans close to lift it away, their faces inches apart, but a scream shatters the moment: Benjamin has fallen from a tree. Thursday carries the unconscious boy to Preston, while Agnes, horrified at being seen, flees.
The doctor pronounces Benjamin's injury not life-threatening, but Silas's fury triggers a devastating revelation. Under pressure, Leah confesses that Cora's mother was not a Maroon but a person who escaped enslavement. Leah, on patrol, captured her and returned her to her plantation, as the Maroons' treaty with the British required. Leah took the newborn Cora and told the others the baby had died. This was Leah's act of mercy: saving the child while surrendering the mother to bondage. Shattered, Cora walks out into the night.
She flees to Agnes and chooses the forest permanently. As autumn arrives, Cora settles into wilderness survival and acknowledges what Agnes is to her, settling on the word "love." In late October, a bear rears over Agnes, and Cora charges at it screaming until it retreats. Patience is wounded but alive. Trembling with relief, Cora and Agnes kiss for the first time. Agnes shares her history: Growing up enslaved in Virginia, she recognized early that her desire would never be directed toward men. Her mother responded with stories from her African grandmother about men who married men and women who married women, traditions lost on the passage from Africa.
Winter tests them. Cora falls through the ice of a frozen lake, and Patience drags her to shore, but Cora collapses, delirious with cold. Agnes loads her onto a sled and drags her four miles to Shelburne, where Thursday carries Cora to a doctor. At dawn, soldiers intercept Agnes, seeking a runaway from the Dalton land. Patience attacks the soldiers and is shot dead. Agnes is dragged away screaming.
Thursday files a petition on Agnes's behalf, and the case goes to trial. Henry Dalton, a young white planter, claims Agnes as his family's property. He tells the court that Agnes's mother, Zilpah, poisoned his sister and died soon after, framing Agnes as dangerous. In a jail visit, Agnes confesses to Cora that she mixed the poison, though it was intended for the enslaver, not the sister. Cora recoils but then kisses her: "No perfect choices."
When the trial resumes, Dalton produces a bill of sale. Before Thursday can testify, Leah walks down the aisle and tells the court that Agnes is a Maroon whose freedom is guaranteed by the British Crown. The judge notes the bill of sale names Zilpah, not Agnes, and that Dalton's identification rests on a childhood memory from over a decade ago. Pressed to confirm his certainty, Dalton hesitates, and the judge declares Agnes free. Outside the courthouse, Leah reveals that Silas spread word about Agnes after Benjamin mentioned her name, leading to Agnes's capture. Cora recognizes Leah's testimony as an act of atonement for all the people Leah returned to bondage, an exercise of the freedom she has fought for her entire life.
In spring 1800, Thursday arrives on the coast, free at last after Nash's death, and delivers a message: The Maroons are leaving for Sierra Leone, and Leah wants to see Cora. Cora returns to Preston, embraces Leah, and sees Benjamin, now on the cusp of manhood. Leah asks Cora to come to Africa. Cora declines, unable to leave Agnes. Leah says haltingly that she does not understand the bond between them but can forgive it. Cora begins to name what Agnes is to her but sees Leah tense with warning and stops. She holds Benjamin one last time, carrying the ghostly weight of him as she walks back into the forest.
In August 1800, Cora and Agnes watch from a clifftop as the ships carrying the Maroons to Sierra Leone glide out of the bay. In their wake, humpback whales breach against the morning sky. Cora closes her eyes and wills Leah and Benjamin to look back. When she opens them, the whales have vanished and the ships have slipped over the horizon. Agnes rests her head on Cora's shoulder. Their new dog, Faith, pants beside them in the summer heat. Behind them, the forest grows thick, sheltering a whole world of living things. They stay on the cliff, breathing together, unhurried, before returning to the wilderness they have made their home.