In Lexington, Kentucky on a snowy winter night in 1964, Norah Henry goes into labor. Her husband David Henry, an orthopedic surgeon, is forced to deliver the babies himself when their obstetrician gets caught in the snowstorm. With the help of a nurse, Caroline Gill, David delivers a beautiful baby boy named Paul—and is shocked when a second baby arrives. The second child, a girl named Phoebe, is born with Down syndrome. Recognizing the medical—and social—complications that accompany the syndrome, David gives Phoebe to Caroline and orders her to take the child to an institution in the countryside. Caroline drives through the snow to the address David has given her, but once she sets eyes on the poor conditions, she absconds with the baby and returns to Lexington. When her car stalls out, a kindly trucker named Al brings her and Phoebe back to her apartment. David, meanwhile, has told Norah—who was slightly drugged during the birth—that though she delivered twins, the girl died at birth. The devastated Norah returns home with her son Paul and attempts to push through the grief she feels—grief no one else around her will acknowledge. Norah insists on holding a memorial service for Phoebe, and David reluctantly agrees. Caroline, meanwhile, sees an ad for the memorial service in the paper, and decides to take Phoebe out of town and give them both a fresh start.
Over the years that follow, the novel follows the perspectives of David, Norah, Caroline, and Paul as the four of them wrestle with the unspoken secret at the heart of all their lives. While Norah tries to ignore the eerie sense that her daughter is still out there somewhere, David struggles with the desire to tell the truth—and the fear of what will happen if he does. He is haunted by a past marked by poverty, grief, and loss—David’s younger sister June died of heart failure as a child, and his desire to prevent pain like that from seeping into his marriage to Norah was at the heart of his plan to give Phoebe away. He develops an obsession with photography as a way of coping with his inability to control time, always hoping that he will be able to capture one moment that feels as important and life-changing as the moment in which he chose to give his daughter away. Meanwhile, Norah balks against David’s distant, aloof refusal to admit to the grief he feels over their daughter’s loss, or to even talk about her. She develops a slight drinking problem and often behaves recklessly for attention. As Paul grows older, she becomes deeply overprotective of him, desperate to keep her remaining child safe for as long as she can. Caroline, meanwhile, finds work as a private nurse to a grouchy old man named Leo, and takes up residence in the large house he and his daughter Doro share. She reunites with Al and struggles with her fear that Phoebe will never be able to have a normal life. As Phoebe grows older, Caroline finds a community of other parents of children with Down syndrome, and together they form the Upside Down Society in order to advocate for their children’s right to education, equality, and fair treatment. She begins sending letters and photographs of Phoebe to David, and he sends money—but never any letters—in return.
As Paul grows into a teenager, he becomes angry, moody, and rebellious. He smokes marijuana with his friends, plays music nonstop, and finds himself wondering often about the sister he never knew. He knows his parents’ marriage is on the rocks—his mother, now a high-powered travel agent, has had at least one affair, and though his father’s photography career has gained traction, David balks at Paul’s own desire to become a musician and study at Juilliard, insisting Paul needs to find a more traditional career. Paul, Norah, and David orbit one another but have no real sense of family or connection.
On a trip to Pittsburgh for the opening of a museum exhibit dedicated to his photographs, David is shocked to find himself face-to-face with Caroline Gill. The two talk privately, and Caroline tells him that Phoebe is growing up to be a happy, healthy girl who is able to attend public school with other children. David tells Caroline to stay until the end of the opening, hoping to continue a conversation with her and discuss reuniting their two families, but he is dismayed when she slips away. David, reeling from the pain of what he’s done to his own family, takes a bus to West Virginia and returns to his parents’ house, to which he still holds the deed, hoping to confront the past. He finds a pregnant sixteen-year-old girl named Rosemary squatting there—he tells her the truth about who he is and the things he’s done, but Rosemary doesn’t judge him or look down on him. Taken in by her beautiful paper cuttings and moved by a desire to shelter a young woman to make up for his cruel treatment of Phoebe, David brings Rosemary home to Lexington, where a furious Norah demands David move out.
Years later, David has been living platonically with Rosemary for years, helping her to raise her son Jack. She announces that she’s going to move home to Pennsylvania, and David accepts her decision with both sadness and optimism. He goes out for a run, determined to visit Norah and tell her the truth about Phoebe once and for all—but when he gets to the house they used to share he finds it empty, and remembers that Norah is on vacation in Europe with her new boyfriend Frederic. David tries to leave a note explaining the past, but can’t find the words. He fixes a leaky faucet for Norah and resumes his run.
Weeks later, in Europe, Norah meets with Paul at the Louvre. She has been on vacation, and Paul has been touring Europe and studying music in various countries. She breaks some sad news: David passed away from a massive heart attack nine days ago. There wasn’t time to contact Paul for the funeral, which Norah returned home briefly to organize and attend. Paul is shaken, but has trouble feeling grief for his father, with whom he always had a contentious and painful relationship. Norah insists that David always loved Paul. As she bids her son goodbye and returns to the hotel where she’s staying with Frederic, Norah gives thanks for her life—and for the roundabout ways in which her struggles ultimately made her stronger.
In Pittsburgh, Caroline and Al are dealing with the now twenty-four-year-old Phoebe’s burgeoning sexuality and desire for romance and independence. Phoebe has a boyfriend named Robert, and she is determined to marry him and live on her own. Caroline is afraid to let her daughter go and move her into a group home—but when a local bank calls to inform her that an account with a large sum of money in it has been created by David Henry in Phoebe’s name, Caroline and Al begin to realize that perhaps they and Phoebe can each have a shot at independence for the first time in all their lives.
A year later, Norah is preparing to move out of the house in Lexington she once shared with David and Paul. She is moving to France with Frederic. As she combs through David’s photographs, preparing his archives for appraisers who believe his work is worth over fifty thousand dollars, she finds a puzzling cache of photos of girls and young women. When the doorbell rings, Norah answers the door to find Caroline Gill standing on her doorstep. Caroline tells Norah the full truth about Phoebe and then leaves, promising that her home in Pittsburgh is always open should Norah want to meet Phoebe at last. Though devastated by the news, Norah cannot deny a sense of relief as all the strange, “jagged” pieces of her life begin to make sense. She starts to understand why David was always so determined to bury the past and yet linger in it as well. Unable to cope with the feelings she’s having, Norah angrily begins burning some of David’s photographs. Paul arrives to help her pack up the house, and Norah tells him the truth about Phoebe. Paul is similarly confused, shocked, and angry—but he urges Norah to stop burning the photographs and focus instead on packing up the house and removing themselves from their obsession with the past.
Shortly after packing up the house, Paul and Norah decide to drive to Pittsburgh to meet Phoebe. The meeting is awkward and difficult, uncharted territory for everyone involved, and yet Paul and Phoebe make a profound connection. Paul and his sister share a love of music, and Paul finds himself realizing that though Phoebe is different, there’s nothing about her to pity or grieve—in many ways, she’s more well-adjusted to the world and optimistic about the future than Paul himself is.
Months later, at Frederic and Norah’s wedding in Lexington, Paul and Phoebe enjoy the festivities and prepare to send the newlyweds off to their lives in France. As Paul and Norah watch Phoebe dance, eat cake, and dream aloud about a wedding of her own, Paul expresses anger at the fact that David derailed all their lives and kept the truth from them for so long. Norah, though, urges Paul to forgive his father—or at least to try. After the party, Paul, who is driving Phoebe back to Pittsburgh to stay with her while Caroline and the recently-retired Al take their first solo vacation ever, pulls over at the Lexington cemetery. Together, he and Phoebe visit David’s grave. Phoebe begins singing a hymn for the father she never knew, and Paul takes her hand and sings along.