Protagonists Henry and Clare each give their perspective on Henry’s time-traveling disorder. Henry expresses his frustration at being pulled from the present into often uncomfortable and even dangerous situations in other timelines. In these other timelines, he must steal and lie to survive, and he never knows how long it’ll be until he returns to the present—the place he longs to be most. Henry knows that his wife, Clare, is forced to wait and worry until he returns. Clare, meanwhile, compares herself to a wife watching sea for her husband’s return.
The narrative shifts to 1991. Clare visits the Chicago’s Newberry Library and runs into Henry. While Clare immediately recognizes Henry, she is a stranger to him. Still, Henry agrees to go to dinner with her. At the restaurant, Clare tells Henry that she knows about his time travels. She explains that Henry began visiting her in the meadow behind her parents’ home when she was a child. Henry does not recognize her because he won’t make those visits until he is older. After dinner, they go back to Henry’s apartment and have sex. Clare finds another woman’s lipstick in the bathroom, but Henry assures her that his ex-girlfriend Ingrid is in the past.
Through flashbacks, Henry remembers his early time traveling experiences. His first time-traveling trip occurs on his fifth birthday when he time travels to the Field Museum of Natural History after hours and meets an older version of himself who has come to explain Henry’s strange condition. In a separate time traveling trip, 36-year-old Henry finds himself in the meadow of Clare’s family home. Six-year-old Clare arrives and is startled when she sees Henry for the first time. Henry tries to explain his time traveling condition, but Clare is unconvinced until he vanishes before her eyes.
Other time-travel episodes recount the times that older versions of Henry meet up with his younger self to teach him valuable skills and lessons related to his disease, like pickpocketing. He also explains to his younger self that while time traveling helps him know what will happen, it doesn’t allow him to change the results.
Flashbacks to Clare’s childhood highlight the effects Henry’s visits from the future have on her as she grows up. As Clare comes into her teenage years, her infatuation with Henry grows. Henry and Clare discuss how Henry, despite his best efforts to withhold the most impactful details of the future, may be shaping Clare’s identity when he mentions aspects of Clare’s future personality and preferences.
On one of Henry’s visits to young Clare, Clare wakes before dawn to the sound of someone shouting her name. When she goes outside, she finds Henry standing with her brother Mark and her father Philip in their hunting gear. Henry motions for her to stay quiet while her father ushers her inside.
Another visit to Clare occurs on Christmas Eve, which is the anniversary of his mother Annette’s death. Because she died when Henry was only six, Henry understands that his condition gives him extra opportunities to witness her alive and happy. Clare arrives home in the middle of Henry’s reflections on his mother, and he decides it is time to tell her about his mother. He describes the car accident that led to her death and would have killed him too if he hadn’t time traveled away from the car at the last moment. A flashback reveals Henry on another Christmas Eve night, where his grief drives him to drink until he ends up in the hospital with alcohol poisoning.
In the novel’s present (the timeline that begins with Henry meeting Clare at the library), Henry and Clare continue to date. She introduces him to her roommate, Charisse, and Charisse’s boyfriend, Gomez. While Charisse loves Henry, Gomez is suspicious of him and overly protective of Clare. And Clare herself has doubts about Henry after Celia, the friend of Henry’s ex-girlfriend Ingrid, warns Clare about Henry’s pattern of disappointing women. Shortly after this, an older version of Henry visits Clare from the future and tells her that present-day Henry needs Clare’s help to become a better person.
That Christmas, Henry goes home with Clare to meet her family and childhood friends. Henry manages to make a good impression despite the family’s internal struggles. A few months later, Henry goes to his father, Richard, to ask for Henry’s mother’s rings to give to Clare. They fight, but Richard eventually admits he needs to seek help for his alcoholism and gives Henry his mother’s rings. Henry proposes to Clare on her 21st birthday, and she agrees to marry him. The following week, she meets Richard and Kimy, a family friend who helped raise Henry.
As the wedding approaches, Henry attempts to find a treatment that will prevent him from time traveling on his wedding day. When nothing works, Clare insists that Henry stop trying, and he agrees. On their wedding day, Henry has a time-traveling episode, but an older version of himself comes from the future to fill his role during the ceremony.
Clare and Henry try their best to adjust to married life despite the conflicts that arise now that they live together. Clare grows frustrated by the way their small apartment limits her art—her paper sculptures, which usually depict birds, tend to be large, but she can only make miniatures now. Seeing Clare’s unhappiness, Henry uses his knowledge of the future to win the lottery. The couple uses Henry’s winnings to buy a house with a separate studio space for Clare.
Henry’s episodes start to happen more frequently, so he and Clare track down Dr. Kendrick, a geneticist who future-Henry told them will become his doctor. Once they convince Dr. Kendrick that time traveling is real, he begins working on sequencing Henry’s genes in hopes of finding a cure.
Clare and Henry experience more setbacks, including several tragic miscarriages and the death of Clare’s mother. After Clare’s mother’s death,. When Clare and Henry return home following the death of Clare’s mother, they resume trying to conceive. Clare remains determined, but Henry begins to believe that the risks of pregnancy are too great and gets a vasectomy without telling Clare. She eventually gets pregnant anyway after she has sex with a version of Henry who visits from the past.
Toward the end of the pregnancy, Clare and Henry pick out a name for their daughter that means “white” and symbolizes a clean start: Alba. Through his time traveling, Henry learns that he will die when Alba is five, but he doesn’t share this the information about his death with Clare. Two weeks later, Alba is born perfectly healthy. After Alba’s birth, Clare grows to appreciate the time she gets to herself when Henry is away time traveling. It gives her space to bond with her daughter and focus on her art. Meanwhile, Henry’s time travels become even more frequent and end often in injuries.
One day, Alba (who can also time travel) comes from the future to visit her younger self. Clare can tell from future Alba’s emotional reaction to seeing Henry that something will happen to him. Henry admits the truth, which stirs Clare’s memory of the morning in her childhood when she woke up to someone calling her name. She tells Henry that she believes that may be where and when he dies. Not long after their conversation, Dr. Kendrick tells Henry that he is simply too old and immunocompromised for any kind of treatment, though he agrees to continue working on a cure of Alba.
Months later, Henry has a particularly bad time-traveling episode. In it, Henry is exposed to the cold for an extended period, resulting in the amputation of both his feet. He sinks into a depression and rarely leaves his bed. In an effort to process her own frustration and grief, Clare makes a giant set of red and black paper wings for Henry. When he sees them, he finally breaks out of his sadness. Because the loss of his feet means Henry can no longer run from dangerous situations when time traveling, however, he feels his death must be approaching.
On New Year’s Eve, Henry and Clare have a party. They invite all their friends and family, and Henry sees in them a representation of his whole life. Later in the evening, Clare finds Henry alone on their front porch. He tells her that the time has come, and they lie together until Henry vanishes. When he reappears in the living room, he finds that he has been shot in the stomach. He bleeds to death.
After Henry’s death, Clare is inconsolable. She reads the final letter Henry wrote her before his death. In it, he reminds her how much he loved her and thanks her for guiding him through life. He expresses his wish that, after a lifetime of waiting for him to appear, Clare can now live life fully in the present now that he’s gone. But he also tells her that he knows that a past version of himself will visit her one more time in the future when she is very old. Clare tries her best to live as Henry asked. As time goes on, she makes art to cope with her grief over losing Henry.
In a flash forward, 43-year-old Henry finds himself in strange place where he encounters an old woman. When she turns to face him, he realizes it’s Clare and reaches out for her. The narrative switches to Clare’s perspective just before the encounter. Clare sits by the window and considers all the years she has waited for Henry to return one last time. She wonders if that means he’ll never come—but she waits, nonetheless.
