In the summer of 1999, Ellie Connor, a music biographer, drives into the small east Texas town of Gideon to research the life of Mabel Beauvais, a blues singer who vanished in 1953. She has accepted an offer from Dr. Laurence Reynard to stay in the guesthouse on his estate, Fox River, after months of online correspondence. When she arrives, she finds that Reynard, who goes by Blue, is not the middle-aged figure she imagined but a strikingly handsome man with a deep Southern drawl and a taste for bourbon. His friend Marcus Williams sits with him on the veranda.
Ellie has a secret reason for choosing Gideon. Her mother, Diane Connor, was a restless runaway who spent the summer of 1968 in this town before returning home to Sweetwater, Louisiana, pregnant and broke. Diane never named the father. She gave birth to a girl she called Velvet Sunset, left when the baby was three months old, and later died of a heroin overdose. Raised by her grandmother, Geraldine Connor, Ellie has only postcards her mother sent from Gideon as clues to her father's identity.
Blue introduces Ellie around town. She meets Rosemary Grace, Mabel's niece, who owns a bookstore and grants Ellie access to family letters and photographs in her attic. At a beauty salon she meets Connie Ewing, a widow, and Alisha Williams, Marcus's much younger wife. Several people remark that Ellie looks familiar, but she deflects. Blue reveals his PhD is in botany; his greenhouses hold orchid propagation experiments aimed at preserving rainforests.
In Rosemary's attic, Ellie discovers a group photograph from a going-away picnic for boys shipping out to Vietnam and recognizes her mother, a young redhead in Indian cotton. She secretly takes photos of Diane. At the county library, she covertly searches 1968 newspapers and yearbooks, narrowing her list of possible fathers to three men: Dennis Nicolson, killed in Vietnam; Bobby Makepeace, Connie's boyfriend, also killed; and Todd Binkle, an athlete who survived.
Interspersed throughout the novel are lyrical vignettes titled "The Lovers," depicting an unnamed interracial couple's secret affair. They make love in stolen hours and meet in the woods before the man ships out. She lets him believe they will find a way to be together but privately knows their situation is impossible. Their identities are gradually revealed as Ellie's parents, James Gordon and Diane Connor.
Ellie and Blue grow closer despite her determination to resist him. Everyone in town warns her that Blue is a heartbreaker. She attends the Gideon Readers' Group, a women-only book club at Rosemary's store, and steers conversation toward 1968. Connie and Rosemary recall Diane and share memories of the boys who went to war. On Blue's porch, Ellie challenges Blue about his drinking, suggesting he uses bourbon as a wall against feeling. She tells him she recognizes their pattern: She tries to save drowning men, and he clings to women when lost. They agree to remain friends.
Blue takes Ellie into his largest greenhouse, a lush ecosystem he built after the death of his wife, Annie, in a car accident five years earlier. Ellie calls it his "Taj Mahal." One afternoon, watching him stand with arms outstretched beneath a mist shower, she surrenders. They become lovers, and the days that follow are golden. She works on her biography by day and spends nights with Blue, though she privately resolves to leave when the research ends, convinced she cannot save him from himself.
Over lunch with Doc, the elderly bartender at a blues club called Hopkins' Juke Box, Ellie learns that Mabel was in love with a charming hustler called Peaches, whose real name was Otis McCall. Peaches was shot dead outside the club in 1952, months before Mabel vanished. Doc refuses to reveal more. At a photo-sorting gathering for a Vietnam memorial project, Marcus suddenly recognizes Ellie's resemblance to his childhood best friend, James Gordon: the same laugh, the same overlapping tooth. He leaves without revealing what he has realized.
Acting on advice from Gwen Laisser, an elderly neighbor, Ellie visits Hattie Gordon, Peaches's mother, who reveals the full truth. Mabel dressed entirely in red, went to Hopkins', and shot Peaches through the heart after he betrayed her with another woman. She drove away and was never seen again. Hattie also reveals that Mabel left behind a child, James Gordon, whom Hattie raised. Ellie concludes that Mabel gave up her music as atonement for killing the man she loved.
Marcus comes to Ellie's cottage and tells her what he has known since the photo-sorting evening: James Gordon is her father. He shows her a photograph, and Ellie weeps, recognizing her own features in James's face. Being James's daughter also makes her Mabel Beauvais's granddaughter and Rosemary's second cousin. Marcus explains that James never knew Diane was pregnant and was killed on June 3, 1969, around the time Diane abandoned baby Ellie for good. That same day, Ellie discovers she is pregnant with Blue's child.
On a sudden intuition, she rushes through a rainstorm to Gwen's house. Gwen removes her thick glasses, revealing the unmistakable eyes of Mabel Beauvais. She confirms her identity, explaining she returned to Gideon years after the killing and lived near her own son, whom Hattie kept from her as retribution. While Ellie shelters there, a violent storm destroys the cottage, crushing the bed where Ellie would have been sleeping. Blue races to find her, discovers the wreckage, and notices a pregnancy test in the bathroom.
When Ellie confirms the pregnancy, Blue tells her he loves her and shows her the ruby ring he bought to propose. But the sight of the crushed bed has broken him. Haunted by a lifetime of losses, he cannot face the risk of losing her or a child. Ellie, hurt but unwilling to beg, tells him she will go home and have the baby. She drives away.
Blue drinks on the porch while Connie, Rosemary, Alisha, and Marcus each tell him he is a fool. That evening, Gwen arrives and reveals she is Mabel, Ellie's grandmother, and the only family Ellie has left. She dismantles Blue's belief in a curse, pointing out that his losses were caused by human choices and chance, not fate. She orders him to go after Ellie. Blue, finally broken open, weeps.
He drives through the night to Sweetwater with Marcus. At Geraldine's farmhouse, he tells Ellie he panicked and was wrong. He wants ordinary days, babies, laughter, and music. He offers the ruby ring, saying rubies suit the life in her. Ellie accepts. They agree that when the blue times come, they will sing the blues for each other.
On a rainy Fourth of July, the Vietnam memorial is unveiled in Gideon. After the ceremony, Connie lingers alone, pressing her fingers to Bobby Makepeace's carved name. From the nearby hall, Mabel's voice rises in song for James, for Ellie, and for all the sorrows Ellie's arrival has helped to mend. The sun breaks through the clouds.
The novel closes with a letter from James to Diane, found in his pocket after he died. He writes that he is grateful their love made a child and asks Diane to call the baby Ellie. He tells her to kiss their daughter and say her daddy loves her.