In the small town of Magnolia, South Carolina, the Foster family lives on Nolia Farms, an 850-acre tobacco farm. Austin Foster, the eldest daughter, narrates a story spanning nearly a decade of the 1980s as she shoulders the care of her six younger siblings and her father, Dave Foster, a charismatic preacher whose untreated mental illness slowly tears the family apart.
The story opens in 1987 with Austin observing Dave lead a Sunday service with manic energy. She notices a repaired beam in the chapel ceiling, a detail testifying to a dark event she does not yet reveal, and locks eyes with Vance Archer Cumberland, the mayor's son, whose glance carries years of unresolved tension.
The narrative rewinds to October 1980, when Austin is 13 and her mother, Edith, is on bed rest with preeclampsia, a dangerous pregnancy complication. Edith, who names each child after a city she dreams of visiting, circles Nashville and Knoxville on a Tennessee map for her expected twin boys. Dave takes most of the children to a county fair, where Austin's younger brother Phoenix, called Peg, befriends Foxy Deveraux, a fortune-teller from New Orleans. Dave tries to recruit Foxy and her husband Jinx to work on the farm, but they only agree to consider it.
Austin rushes home to tell her mother about Foxy but instead finds horror: one blue baby, Knox, not breathing, the other, Nash, weakly crying in Mama's lifeless arms, blood soaking the Tennessee map. Mama has died during an unattended home birth. At the funeral, Vance approaches and tells Austin, "I . . . I never want to know how you feel right now" (28). His honesty comforts her when nothing else can. Dave locks himself in his bedroom for a week. With no other adults to help, 13-year-old Austin forces him out of bed and becomes the sole caretaker for her six siblings and her father.
Six months later, Foxy and Jinx move to the farm. Foxy becomes Austin's mentor in herbal remedies but refuses to intervene in Dave's erratic behavior. When Peg confronts a racist customer who insults Foxy, Dave takes Peg to the packhouse barn to discipline him but instead whips himself with his own belt, screaming that he has failed as a father. The other children watch in terror.
Austin befriends Helena Wisniewska, an elderly Polish woman the town calls Miss Wise. After a tobacco barn fire triggers Miss Wise's traumatic breakdown at the sight of falling ash, Austin discovers she is a Holocaust survivor who was held at Auschwitz. Devastated, Austin stops eating until Miss Wise seeks her out, shares her own story, and force-feeds Austin pastries. A lasting friendship forms around shared vulnerability.
Vance begins volunteering with Austin's brother Boston, nicknamed Boss, who has an intellectual disability. Vance visits the farm regularly, but Austin keeps him at a distance to hide Dave's condition. Dave cycles between manic highs and devastating lows. During one low, he drives his truck into a pond in what Austin recognizes as a deliberate suicide attempt, though police attribute it to brake failure. During a manic upswing, he purchases a retired funeral home limousine that becomes the family's only car.
By the summer of 1983, Vance works alongside the Fosters during tobacco season, trading his sports car for a pickup truck. Austin falls in love but fears her chaotic life will destroy his. On New Year's Day 1984, they share their first kiss at his family's lake house. That same night, Dave mistakes Austin for her dead mother and asks about bloodletting, the practice of cutting oneself to release impurities. Terrified, Austin hides every knife in the house. Alone afterward, she cries for the first time since Mama's death, but the tears do not return, replaced by deep anger.
Months later, Austin is bitten by a copperhead snake while protecting her young brother Knox, and Vance publicly declares her his girlfriend at the hospital. The year 1985 shines as the family's brightest season. Dave seems restored, organizing a Harvest Day celebration where each congregation member, including the town's hairstylist Walynn Posten, the undertaker Morty Lawson, and Tripp, an ex-con with a glass eye, testifies about gratitude. Austin recognizes the joy cannot last.
In April 1986, Austin discovers Dave in the chapel attempting to hang himself. The beam buckles under his weight and he crashes to the floor. Austin hides the evidence. Desperate to protect Vance, she visits his lake house but finds him hosting wealthy college friends. Vance does not introduce her, and one of his friends mistakes her for a limo driver. Humiliated, she breaks up with Vance, insisting their worlds are too different. In a gas station parking lot on the drive home, she experiences a brief flash of suicidal ideation before the faces of her siblings pull her back.
Without Vance, Austin unravels. Dave's illness affects every family member, including her younger siblings Charlotte and Raleigh. In 1987, Dave forces the family to uproot healthy tobacco plants overnight, convinced they are diseased. That summer, he orders the crop stripped prematurely; rain ruins the exposed leaves, and the newspaper publishes front-page photos of the devastation. Vance briefly reappears at church, and he and Austin share a desperate kiss, but she pushes him away again.
The crisis peaks in July 1988. Dave flips the dining table in a rage, then disappears into the tobacco field with a filleting knife. Austin tracks him by his weak singing and finds him with his arms slashed from wrist to elbow. When he refuses to stop, she presses the knife to her own arm and threatens to die beside him. They wrestle for the blade; Austin's forearm is cut before she wrenches the knife free and runs to Foxy's house. For the first time, Austin tells the sheriff the truth: Her father did this to himself, and it is not the first time.
Vance arrives at the hospital and holds Austin without a word. The following Sunday, the congregation gathers and shares their own hidden pain: Foxy reveals burn scars from a childhood hate crime, Miss Wise shows her Auschwitz tattoo, and Walynn, Morty, and Tripp each credit the Foster family for accepting them. Austin collapses at the altar. The congregation surrounds her in prayer and organizes to take in her siblings so she can focus on Dave's treatment.
Doctors diagnose Dave with manic depression, now known as bipolar disorder, and Austin places him in a faith-based institute near the coast. Vance and his father arrange financial protections Dave had quietly prepared, including mining the farm's coquina rock, a shell-based limestone, for revenue. Vance gives Austin a completed college application for Baptist College at Charleston and arranges a disability scholarship for Peg at an aviation academy in Colorado. Over the phone, Vance tells Austin, "I still haven't figured out how to stop loving you, Austin Foster" (344). She reciprocates, and the year closes as one of new beginnings.
Years later, Austin is a practicing psychiatrist. She marries Vance after graduate school, and they have twin boys named after Texas cities, honoring Mama's naming tradition. Dave manages his bipolar disorder with ongoing treatment, still preaches on Sundays, and marries Walynn, who becomes a surrogate mother to the Foster children. Peg becomes an airline pilot, Boss runs the farm's produce stand, Charlotte opens an interior design firm, Raleigh joins the military, and Nash and Knox become missionaries. Austin ties a yellow ribbon on the magnolia tree for Raleigh's safe return and reflects that she does not believe in happily ever after but in healing ever after, an ongoing process the Foster family lives out every day.