As a nine-year-old growing up in a trailer park, Ellis Abbey finds solace in the strip of forest she calls the Wild Wood. After her almost-father figure Zane disappears and her mother sinks deeper into addiction, Ellis begins writing notes to the natural world, tucking them into tree roots and sending them downriver as a form of emotional release.
Years later, Ellis is married to Jonah Bauhammer III, a lawyer and son of a conservative U.S. senator, and is the mother of twins River and Jasper, age four and a half, and two-month-old Viola. On the morning everything unravels, Ellis sees Jonah kiss his tennis instructor, confirming a long-suspected affair. She takes the children to the woods to think, and at the trailhead, the boys' spilled jar of tadpoles creates chaos. Ellis sets Viola's carrier on the ground to help and, in the turmoil, drives away without her baby. She returns within minutes to find the carrier empty. Someone has taken her daughter.
Ellis spirals into depression and dependence on pills and alcohol. Jonah's domineering mother, Mary Carol, moves in and takes control of the household. The case goes cold, and Ellis overdoses. When Jonah says he wants to leave, Ellis reveals she saw his affair the day of the abduction. She initiates the divorce, relinquishes custody of the boys, and leaves, convinced she is damaging them the way her mother's addiction once damaged her. River refuses to hug her and screams that he hates her.
Ellis disappears west. She visits her grandfather Samuel Abbey's grave in Ohio, then returns to her childhood hometown to find the trailer park and Wild Wood replaced by apartment buildings. She buries her phone beneath a rock at the river, severing her last connection to her former life. While winter camping, she meets Keith Gephardt, a kind park ranger. They spend a night together, and Keith hides a toy blue pony in her coat pocket before leaving. Ellis carries it west as a talisman, working toward sobriety.
The narrative shifts to a girl called Raven, about seven years old, living on a remote property in Washington state with her mother, Mama. Mama, whose real name is Audrey Lind, has told Raven she is "Daughter of Raven," a miracle child born of an earth spirit. She teaches Raven "the Asking," a practice of arranging natural objects to communicate with earth spirits. The property is fortified with cameras, alarms, and locks; Mama warns that outsiders might steal Raven. Mama experiences prolonged dissociative episodes she calls entering "the spirit world," during which Raven must care for her. Mama's older sister, Sondra Lind Young, visits once or twice a year with a pediatrician to check on Raven, and the sisters argue about schooling and socialization.
Raven encounters three boys at the creek: Jackie, his brother Huck, and their friend Reece. Captivated by her first contact with children her age, Raven keeps the friendships secret and begins visiting Jackie's house, where his mother, Ms. Taft, a schoolteacher, welcomes her. When Raven tells Mama she wants to attend school, Mama is furious. Raven runs away overnight, and Mama interprets the absence as the earth spirits taking Raven as a warning. Mama consents to school but imposes two conditions: Summers will be spent at a remote Montana cabin, and Raven must never set foot on the Taft property again. Raven promises and never breaks the vow.
Meanwhile, two men attack Ellis in a campground, stabbing her with her own hunting knife. She escapes but refuses medical help. Keith drives through the night to find her and takes her to a hospital, then to the home of her college friend Danielle "Dani" Yoon in Gainesville, Florida. Ellis develops panic attacks that prevent her from camping alone. She settles in Gainesville, works at a garden shop, befriends Maxine "Max" Kidd, a carpenter who is deaf, and buys rural property where she opens a native plant nursery called Wild Wood Natives. Keith reappears after breaking off an engagement, and they live together for 10 years. Ellis refuses marriage and children. Keith does not know she has children.
In Washington, Raven enters high school. Mama allows her to date, claiming Raven cannot get pregnant because of "reproductive isolation" between her half-spirit body and human males, and urges her to have sex to produce a baby. After a turbulent relationship with a classmate ends, Raven and Jackie grow closer, begin a relationship, and make love during spring break. Raven believes she cannot conceive. Mama's health deteriorates from an untreated heart condition. In March, Mama says a tender goodbye and vanishes. Raven searches the property for days, finds nothing, and lives alone for weeks.
Aunt Sondra arrives with Mama's will, mailed by an attorney on a specified date. The letter reveals Mama prepared her own burial site and died by her own hand. Sondra notices Raven's resemblance to a news photo and connects the name Bauhammer. A DNA test confirms Jonah is Raven's biological father. Everything Mama told Raven was a lie: She was stolen from a family in New York.
Sondra takes Raven to meet Jonah and his family. Raven dislikes them. River, now a hostile college dropout, reveals that Ellis lives in Florida. Raven insists on going to her. When Raven appears at Ellis's gate, Ellis recognizes her own face in the teenager. Keith learns for the first time that Ellis has children. Devastated, he leaves. Raven moves in, not seeking a mother but a temporary home until she can return to Washington.
River and Jasper, Ellis's now-grown sons, arrive unannounced. River secretly contacts Zane, lying that Ellis is dying. Zane reveals that Ellis's father, Lucas Rosa, was a Portuguese American chef killed in a motorcycle accident when Ellis was three. After Lucas's death, Ellis's mother transferred her hatred of him onto Ellis, who resembled him.
River takes Raven to dinner, then crashes the car while intoxicated into the wetlands of Paynes Prairie, south of Gainesville. As the car sinks, Raven drags the unconscious River through her window and keeps his head above water until bystanders pull them out. River survives and enters a coma. Keith returns to Ellis, she tells him everything, and he stays. At the hospital, Jonah privately tells Ellis he is gay and has found love with a man named Ryan. Ellis forgives him. Raven covers River's body with grass and flowers, insisting the sterile hospital prevents healing, and he wakes shortly after.
River remains in Florida, working a landscaping job and attending recovery meetings. During a hurricane, Raven feels the baby move inside her for the first time. She is roughly six months pregnant from her relationship with Jackie, a pregnancy made possible by Mama's lie about reproductive isolation. Inside a hollow oak during the storm, Raven tells Ellis everything. Ellis gives her a phone to call Jackie, who says he still loves her.
During a December gathering, Raven announces she will go by her legal name, Viola Abbey Bauhammer, to honor Ellis. On Christmas Eve, Viola goes into labor in the meadow Ellis seeded with native wildflowers. Ryan, a surgeon, assists as the family gathers. Under clearing skies, Viola delivers a girl they name Meadow Rose, for the field, for Jackie's mother Rose, and as an echo of Ellis's father's surname, Rosa. Viola and Jackie ask Ellis and Keith to raise the child, acknowledging they are too young for full parenthood. Keith asks Ellis to marry him, and she says yes. The family's joy carries out over the Florida land that Ellis has made into her own Wild Wood.