Dell Sommerfield is a 20-year-old woman of Choctaw heritage who was adopted at age 12. She secretly travels to Oklahoma to search for the biological father she has never known.
Dell's early childhood was marked by neglect. Her mother, Jesse, had a drug addiction and eventually died of a meth overdose. Dell's father, Thomas Clay, was listed as Choctaw on her birth certificate but was absent. She grew up in her grandmother's house in Hindsville, Missouri, where her Uncle Bobby called her degrading names because of her dark skin. An elderly neighbor, Mrs. Vongortler, whom Dell calls Grandma Rose, provided the unconditional love Dell's family could not. After Grandma Rose's death, her granddaughter Karen and grandson-in-law James Sommerfield adopted Dell, giving her a loving home where her musical talent flourished.
Now 20, Dell has returned to Kansas City after two years abroad touring with a student exchange orchestra in Europe and teaching orphans in Ukraine. Her longtime friend and former boyfriend, Barry, picks her up and drives her to a family gathering at Aunt Kate's farm to see cousin Jenilee's new baby. As Dell holds the infant and listens to relatives compare the baby's features to various family members, a painful truth solidifies: Not a single face in the circle looks like hers, and none ever will.
This realization intensifies a restlessness Dell has carried for years. In high school, her counselor, Mrs. Bradford, suggested Dell research her Choctaw heritage through the tribal offices in Oklahoma, but the prospect reopened wounds Dell thought she had closed, and she fled to Europe instead. She also privately grieves for her baby brother, Angelo, who was taken away by his father when Dell was about eight. She confides in Barry that she wants to go to Oklahoma but cannot tell James and Karen, fearing they would think their family is not enough.
After falling ill with flu, Dell has vivid dreams of her mother, Grandma Rose, and Angelo. She wakes screaming Angelo's name, confirming that the unanswered questions about her origins stand like a wall blocking everything else in her life. She decides to go immediately, lying to Karen about visiting Barry at college.
At a turnpike rest stop, two members of the Kiamichi Garden Club redirect Dell to Tuskahoma, site of the old Choctaw Capitol Building, where the tribe's annual Labor Day Festival is under way. The name triggers a buried memory: Her mother once told Dell she was born there. Every hotel is full, so Dell camps at a state park next to the Reid family, a large Choctaw clan. Jace Reid, a history teacher in his early 30s, invites Dell to share supper. His young daughter, Autumn, takes Dell's hand and leads her to the food, while family matriarch Nana Jo commands Dell to sit and eat. Dell learns that Autumn and her brother, Willie, lost their mother to a heart abnormality the previous year.
Dell joins a campfire jam session with Jace's teenage cousin Dillon, and music swells inside her for the first time in over a year. Shasta, Jace's pregnant sister, learns Dell is adopted with a Choctaw father and tells her Jace could help trace her family history. Over the following days, Dell bonds deeply with the Reids. She helps Jace understand Autumn's grief by sharing her own childhood losses, and both children begin calling her "Aunt Dell."
At the county courthouse in Antlers, Lana, a woman who works in records and is possessively pursuing Jace, refuses to process Dell's request. But Shasta's stepcousin Jamie secretly provides a copy of Dell's birth certificate bearing her father's signature: Dell Jordan Clay. For the first time, Dell's father becomes real to her. A library search for Thomas Clay in local yearbooks and phone directories yields nothing.
Jace gives Dell a tour of the Choctaw Capitol Building museum, describing how nearly one-third of the Choctaw people died during the forced removal from Mississippi in the 1830s. Dell stands before the photographs and the sign reading "Chahta Sia Hoke," meaning "I am Choctaw," and fully claims her heritage for the first time. At Gibson Academy, where Jace teaches, the genealogy search again yields nothing, but Dell discovers a deep connection with Jace when she plays an old piano, losing herself in music.
During the festival, Dell joins the grand entry powwow dance with Autumn and Willie, feeling tribal belonging for the first time. That evening, Jace plays one of his handcrafted flutes for Dell, gives her a smaller one, and kisses her. Dell feels the kiss erase the painful associations of intimacy from her childhood. She also learns that Jace has recorded a CD of flute music called "The Voices of a Thousand Leaves" and takes a copy.
A garden club member recalls a Tommy Clay who lived on a ranch along Cataway Creek Road and draws Dell a map. Jace drives Dell there, where they meet Audie Clay Senior, a frail old man. But Audie's daughter explains that Tommy suffered a hunting accident at 15 that caused permanent brain damage and paralysis, making it impossible he fathered Dell. Dell is devastated.
Her phone then shows 11 frantic messages. Karen tells her an electrical fire broke out at home; James entered the smoke-filled house looking for Dell, inhaled smoke, and doctors discovered a heart blockage requiring surgery. Karen also knows Dell is in Oklahoma. Dell apologizes for lying, and Karen responds with compassion, saying she and James always knew this day might come and that their love is unconditional.
Dell tells Jace she must leave. He kisses her but insists she should not come back for him, urging her to pursue Juilliard and fill the world with music. He is a man 10 years older with two children, he says, and she does not yet know what she wants. He kisses her one last time and walks away.
Inside the capitol building, Dell spots a painting among art show entries being taken down: a young woman with blue eyes and auburn hair by a river. She recognizes her mother. The entry form reads "Jesse in Blue" by T. Clay, booth 103D. Dell races to the booth and finds a second portrait showing her mother cradling a dark-haired newborn. Dell recognizes the baby as herself.
The artist turns around. Dell recognizes him as the man who took her mother from Granny's house for the last time. His name is Terence Clay, Dell's biological father. He explains that Thomas was his brother, whose name he placed on Dell's birth certificate because he believed she deserved better than a drug dealer headed for prison. Terence met Jesse when she was hitchhiking in Missouri, introduced her to drugs, and drifted with her to Nashville before they fled to Oklahoma, where Dell was born. Terence was sentenced to six years in federal prison when Dell was a baby. He had never told Jesse his family lived nearby, so she returned to Missouri with Dell. He also reveals that Tommy's brain damage and paralysis resulted from a bullet Terence accidentally fired when they were teenagers, a guilt he could never escape.
Terence gives Dell a small box labeled "For Dell, From Mama," containing her mother's gold ring, photographs of Jesse holding newborn Dell, and a slip of paper with Angelo's full name, his father's name, and the words "in Tulsa, Oklahoma, maybe," the first lead Dell has ever had to finding her brother. Before leaving, Dell tells Terence that his grandfather still sits in the yard staring at the gate. She does not wait for a response.
In her car, Dell slips her mother's ring onto her finger and reflects that the part of her that was always empty is now filled, not with joy, but with understanding. She starts the car, and Jace's flute music plays on the stereo as she drives past the exit sign reading "Falamat Ishla Chi-ki," meaning "Come Back Again."