In present-day Arlington, Texas, Miss Isabelle, a white woman approaching ninety, asks Dorrie Curtis, her African American hairdresser and closest friend, to drive her to Cincinnati for a funeral. She offers few details, clutching a tiny silver thimble from her vanity as though it holds a secret. Dorrie, a single mother of two who owns a small hair salon, agrees. Over a decade of weekly appointments, Dorrie has become like a daughter to Miss Isabelle, yet she knows almost nothing about the older woman's past.
As they set out in Miss Isabelle's 1993 Buick, Dorrie carries her own troubles. Her teenage son Stevie Junior is skipping classes, and she suspects his girlfriend Bailey is pregnant. She has also begun dating Teague, a kind, patient single father of three, but years of failed relationships have left her deeply afraid to trust any man.
On the road, Miss Isabelle begins telling her story. In 1939, she is a restless sixteen-year-old in Shalerville, a tiny Kentucky town where her father serves as the only physician. Her mother, obsessed with maintaining the family's social standing, keeps Isabelle under tight control. Isabelle's closest companion is Nell Prewitt, the daughter of Cora, the family's Black housekeeper, though the friendship is shaped by rigid racial hierarchy. A sign at Shalerville's border warns Black people not to remain after sundown.
One evening, Isabelle sneaks away from a dull Sunday-school party to visit a Newport nightclub with Trudie, a new classmate. Trudie abandons her on the dance floor, and a man named Louie plies Isabelle with drinks, then drags her into an alley and assaults her. Robert Prewitt, Nell's older brother, who has followed Isabelle out of concern, intervenes and walks her home through Shalerville after dark, risking his own safety by defying the sundown rule. That night, Isabelle reads the racist sign as if for the first time and feels deep shame.
In the months that follow, Isabelle becomes increasingly drawn to Robert, recognizing his intelligence, kindness, and dignity. They begin meeting secretly at the brush arbor, an outdoor shelter for revival meetings behind Robert's church. Their conversations grow intimate. One night, Isabelle disguises herself as a boy and sneaks to a revival service at Robert's church. Afterward, they share their first kiss. Robert insists it must never happen again because of the danger, but Isabelle tells him she thinks she loves him.
Nell agrees to carry letters between Isabelle and Robert after he leaves for college. Their correspondence deepens, and Isabelle eventually proposes marriage after discovering that Ohio, unlike Kentucky, has no law prohibiting interracial marriage. Robert resists but finally agrees after finding work at the Cincinnati docks. In January 1940, they elope. A hostile white minister turns them away, but Reverend Jasper Day at St. Paul's African Methodist Episcopal Church marries them after warning of the dangers ahead. His wife Sarah gives them a silver thimble engraved with "Faith. Hope. Love." (173) as a ring substitute.
The next morning, Isabelle's mother sends her father and brothers Jack and Patrick to find her. They rough up Reverend Day and force him to reveal the couple's address. Jack and Patrick kick in the door, armed with a handgun. Isabelle's father tries to intervene but is overruled. Believing that leaving quietly is the safest option for Robert, Isabelle goes with them, leaving the thimble on the nightstand.
At home, Isabelle's mother locks her in her room and has the marriage annulled. Cora and Nell lose their jobs. Isabelle discovers she is pregnant but hides the pregnancy. When her mother finally notices, a confrontation erupts on the stairs; Isabelle's mother grabs her, and Isabelle falls. She goes into premature labor. A midwife delivers a girl, but Isabelle's mother refuses to let her see or hold the baby, saying only that the child came too early and the outcome was for the best. Isabelle believes her daughter has died.
The parallel present-day narrative tracks Dorrie's escalating crises. She discovers she left cash at her shop and asks Teague to retrieve it, a significant act of trust. Teague reports the shop has been burglarized. Stevie Junior then confirms Bailey is pregnant and reveals he broke into Dorrie's shop and stole the money to pay for an abortion. Dorrie is furious but must protect her son from criminal charges, so she has Teague cancel the police report.
After months of grief, Isabelle leaves home at eighteen with her father's help. She finds work in Cincinnati and rents a room in a boardinghouse. She encounters Nell at a market and learns Robert is joining the army. Nell hints he has moved on romantically, though she is actually trying to protect them both. Believing Robert is lost to her, Isabelle eventually marries Max, a steady, kind civilian she meets at a public dance. She cares for him but does not love him.
In 1943, Robert appears at Isabelle's door in military uniform. He reveals why he never came back: her brothers ambushed him and branded the letter "A" into his side with a heated iron as a warning to stay away from white women. Despite her marriage, Isabelle and Robert make love, and he promises to return after the war. Isabelle discovers she is pregnant but cannot determine whether the father is Robert or Max. She decides to stay with Max for the child's sake, sending Robert away in an agonizing farewell. Robert ships out as a medic and is killed in 1944 shielding a fellow soldier from a mine. Isabelle's son Dane is born, clearly Max's child. The family moves to Texas, where they live a quiet life. Max dies in old age, and Dane eventually dies of cancer, leaving Isabelle largely alone.
In Cincinnati, the two timelines converge. At Linden Grove Cemetery, Miss Isabelle lays roses at Robert's grave. At the funeral home, Dorrie reads the name on the easel: Pearl Prewitt. Inside, Miss Isabelle gazes at portraits of Pearl at every age. Dorrie sees the unmistakable resemblance to both Robert and Isabelle and realizes Pearl is Isabelle's daughter, the baby she believed had died at birth.
Nell, now elderly, explains everything. Isabelle's father secretly followed the midwife and helped bring the premature infant to Cora's house, using his medical knowledge to keep her alive. He sent money for Pearl's care throughout his life but never told Isabelle. Isabelle's mother had forged a note reading, "I do not want this child. Please do not try to contact me" (302), and the Prewitt family believed Isabelle had rejected her daughter. Pearl eventually learned her mother's identity and called Isabelle several times but lost her nerve and hung up. Isabelle remembers those silent calls, which she had fantasized came from Robert.
At the visitation, Pearl's young granddaughter climbs into Miss Isabelle's lap, strokes her skin, and asks if she is her great-granny. For the first time, Isabelle holds a piece of the family she and Robert created.
On the drive home, the women stop in Shalerville, where Isabelle whispers thanks at her father's grave for saving Pearl's life. Back in Texas, Dorrie confronts Stevie Junior, who reveals Bailey has miscarried. Dorrie addresses his theft firmly but with love. Having left Teague a vulnerable voicemail during the trip admitting she pushed him away, Dorrie reconnects with him, and they agree to move forward together.
Miss Isabelle tells Dorrie she is like a daughter, gives her a house key, and "fires" her as a paid hairdresser, insisting family does not charge family. In the final scene, Dorrie styles Miss Isabelle's hair one last time, not at home but at a funeral parlor. Miss Isabelle has died. Dorrie tenderly prepares her, kisses her forehead and cheeks, and covers Miss Isabelle's hands, clasped around the silver thimble. The undertaker waits at the door. Miss Isabelle is ready, wearing a celebration dress.