In October 1949, a hurricane batters a small New Hampshire farming town. Edwin Plank, a farmer and volunteer fire captain whose family has worked the same land for over 140 years, is called out to clear a fallen tree. He finds Valerie Dickerson, a beautiful artist, and her young son stranded in the storm. Valerie's husband, George Dickerson, is away on one of his many failed ventures. Edwin drives them home, but a falling tree traps his truck, and he spends the night. In candlelight, with Peggy Lee on the Victrola, they dance. What happens between them reshapes two families for generations.
Nine months later, on July 4, 1950, two girls are born at Bellersville Hospital. Ruth Plank and Dana Dickerson go home with their respective families, but between birth and discharge, the infants are switched. Connie Plank, Edwin's devout and practical wife, recognizes immediately that the child is not hers. The weight, coloring, and smell are all wrong. Edwin insists they leave things as they are, knowing the baby is Val's child and his own. Keeping her is his way of holding on to the woman he loves. Connie, a dutiful wife in an era when women deferred to their husbands, acquiesces and confides the secret only to her closest friend, Nancy Edmunds.
The Planks are rooted, stable, and religious, with 10 generations on their New Hampshire land. The Dickersons are rootless: George chases failed schemes from novel-writing to vegetable juicer franchises, dragging Val and their children, Ray Dickerson and Dana, from state to state. Connie insists on maintaining contact between the families, organizing annual visits and calling Dana Ruth's birthday sister.
Ruth and Dana narrate in alternating chapters, each a misfit in her own family. Ruth is tall, blond, and artistic, nothing like her short, sturdy mother or four conventional sisters. She adores her father, who calls her Beanpole and recognizes her talent. Connie treats Ruth with stiff, mechanical affection, unable to fully love a child she knows is not biologically hers. Dana is practical and drawn to soil and plants from early childhood. Val, who longs for an artistic daughter, gives Dana Barbie dolls and frilly clothes that hold no interest. Dana dreams of being a farmer like Edwin, who takes a special interest in showing her how crops grow during the Dickersons' strawberry-season visits.
Ruth is drawn from childhood to Ray, a charismatic boy who plays the harmonica and oscillates between manic energy and deep melancholy. The summer Ruth turns 13, Ray feeds her a strawberry mouth-to-mouth at the farm stand, igniting years of longing. Dana, meanwhile, realizes at 13 that she is attracted to women. When she kisses a female classmate, the girl calls her a freak and spreads the news. The family's next move provides escape.
Ruth goes to art school in Boston, supported by her father over her mother's objections. She illustrates
Sexual X-tasy, an alternative sex manual by Josh Cohen, which becomes an underground hit. She collects royalties but remains a virgin at 22, unable to stop thinking about Ray. Dana enrolls at the University of New Hampshire to study agriculture, where she meets Clarice, an art history professor. They fall in love and build a life on a small Maine farm Dana names Smiling Hills, raising goats and making artisan cheese.
At Woodstock in 1969, Ruth and Ray reunite and spend two ecstatic days together before he leaves abruptly. He later flees to Canada to avoid the draft. Years afterward, Ray calls Ruth from British Columbia. She flies to him, and they live together in a remote cabin in an all-consuming relationship. Ray is fragile, prone to melancholy and paranoia, but their connection is overwhelming. He pressures Ruth to have a child. She agrees, and they conceive.
When Ruth calls her parents with the news, Connie responds with alarm. She flies to British Columbia and, while Ruth sleeps, tells Ray that Ruth is Val's biological daughter, meaning Ruth and Ray are half-siblings who share the same mother. By morning, Ray has cut off his hair and sits catatonic. He tells Ruth the relationship was a mistake and orders her to leave. Connie takes Ruth home. Shattered by Ray's inexplicable rejection, Ruth does not resist when Connie takes her to an abortion clinic. She signs the papers and loses her grip on reality for a time.
Ruth eventually marries Jim Arnesen, a kind insurance salesman she respects but does not passionately love. They adopt a daughter, Elizabeth, from a Korean orphanage. Meanwhile, Clarice is denied tenure when a colleague's wife reveals her relationship with Dana, ending their hopes of adopting a child.
Edwin, aging and increasingly forgetful, entrusts Dana with his secret greenhouse project: a strawberry strain he has spent years crossbreeding for sweetness and resilience. He gives Dana flats of his plants, calling them his good daughters. The Plank farm sinks into debt after a barn fire destroys the historic structure and nearly all the livestock. Developers circle, and Victor Patucci, Edwin's longtime hired hand, positions himself to take over.
Connie develops a brain tumor that strips away her inhibitions. She confesses her aversion to sex, rooted in sexual abuse she experienced as a child, and voices her complicated feelings toward Ruth. In her final words, Connie tells Ruth she was a good daughter in the end, not the one Connie expected, but that things did not turn out badly. After Connie dies, Edwin drives to Virginia to visit Val, only to find she has remarried. Val dies suddenly years later. Ruth, unexpectedly pregnant at 42, gives birth to a son, Douglas, on the day of Val's funeral.
At Val's memorial, Dana sees the four Plank sisters for the first time in decades and is stunned by their physical resemblance to her. The truth crystallizes: She and Ruth were switched at birth. Dana keeps this discovery to herself because Clarice has been diagnosed with amyotrophic lateral sclerosis (ALS), a progressive terminal disease. Dana devotes herself to Clarice's care through years of decline. They take a final road trip to Yellowstone, where Clarice asks Dana to help end her life before she loses the ability to communicate. When the time comes, Dana fulfills her promise.
Ruth, now divorced after Jim falls in love with someone else, receives a posthumous letter from Nancy confirming the switch. She finally understands why Connie separated her from Ray: They are siblings. She forgives her mother at last. During a rare lucid moment at his nursing home, Edwin, mistaking Ruth for Val, tells the story of the hurricane night. Both girls were his, he explains, and he just wanted a reminder of the woman he loved.
Ray resurfaces at 60, diagnosed with schizophrenia. He briefly attends Ruth's art therapy workshop but does not return. In a phone call to Dana, he reveals what Connie told him years ago: "We were going to have a baby. Then it turned out she was my sister."
Dana's years of strawberry breeding yield a patented variety she names Clarice. The licensing fees, combined with a large royalty check Ruth receives from a reissued
Sexual X-tasy, allow the two women to buy Plank Farm, outbidding Patucci. Dana sells Smiling Hills, moves her goats, and builds a cabin on the acre Edwin set aside for her. Ruth paints, runs the farm stand, and continues her art therapy work. Ray lives in his group home, playing "Shenandoah" on the harmonica. On visits home, Edwin eats Silver Queen corn at the kitchen table with both his daughters beside him. "What can a man have," he says, "better than good daughters?"