In the fall of 1962, Kitty Miller is a 38-year-old unmarried woman living alone with her cat in a small duplex in Denver's Platt Park neighborhood. She co-owns Sisters' Bookshop on Pearl Street with her best friend, Frieda Green. They opened the store in 1954 after leaving careers that made them miserable: Kitty as an anxious fifth-grade teacher, Frieda in advertising she found hollow. The shop is now failing because the streetcar line that brought customers to Pearl Street has been replaced with a bus route that bypasses it entirely. Kitty's parents are away on a two-month trip to Honolulu for their 40th wedding anniversary.
One night Kitty wakes in an unfamiliar sage-green bedroom. A blue-eyed man named Lars calls her "Katharyn" and asks her to tend to their feverish daughter, Missy. A small blond boy named Mitch calls her "Mama." Although Kitty has no children, she instinctively finds medicine and settles the girl to sleep. The dream ends, and Kitty wakes in her own bedroom with the same Rosemary Clooney song from the dream playing on the radio.
Kitty recalls that in 1954 she placed a personal ad in the
Denver Post. Among the respondents was Lars, a Swedish immigrant and aspiring architect who wrote about his wish for a family. They spoke by telephone for over an hour; Lars mentioned his arrhythmia, which had classified him as 4-F (medically unfit for military service) during the war. They arranged to meet for coffee, but Lars never appeared. Driven by the dreams, Kitty searches the library's microfilm and finds Lars Andersson's death notice: He died of cardiac arrest at age 34, survived by his sister, Linnea, and her husband, Steven Hershall. In a later dream, she learns he had a heart attack moments after they hung up that night, meaning he died the very evening they spoke.
The dreams grow more vivid. Kitty experiences mornings with Lars, explores a house on Springfield Street filled with family photographs, and relives a Paris honeymoon. In the real world, she takes a bus to Springfield Street and finds only an empty lot at the dream house's address. She realizes she has fallen in love with a dead man.
Resolving to stop dwelling on the dreams, Kitty turns to Greg Hansen, a nine-year-old neighbor who struggles to read. She writes custom stories featuring Greg alongside his hero, Willie Mays, with illustrations on every page and vocabulary flashcards. Greg tears through the first book in a day. The tutoring gives Kitty purpose, and the dreams stop for over a week. She also visits Linnea Hershall, Lars's sister, at a hair salon called Beauty on Broadway. When Kitty sees Linnea's blue eyes, identical to Lars's, she is moved to tears. The two women bond over a shared love of literature.
The dreams return with a disturbing revelation. During a shopping trip, Kitty panics and asks about "Michael," a name that surfaces involuntarily. Missy explains that Michael is at home. The children are not twins but triplets. In the next dream, a bespectacled boy charges at Kitty shouting "Mama," but his eyes do not meet hers. Startled, she swears at him, and Michael lets out a piercing shriek. Lars rushes in, calms the boy, and turns on Kitty with fury. In the real world, Kitty witnesses a child's screaming meltdown in the bookshop and learns the girl has autism. She reads in a psychology book that the condition is "commonly thought to be caused by emotionally distant parenting, generally on the part of the mother," a now-discredited theory that was widely accepted at the time.
In a later dream, Kitty spends a morning alone with Michael, who calculates his age with astonishing precision and reveals he does not attend school. At a grocery store, an acquaintance whispers condescendingly about Michael, and he bolts screaming through the parking lot. Kitty brings him home but cannot calm him.
The two worlds begin to blur. In the dream world, Kitty finds Sisters' boarded up and discovers Frieda has built Green's Books and News into a six-store chain. A shopgirl explains that Mrs. Andersson walked out on the partnership after a terrible fight. Kitty wakes devastated. Separately, she and Frieda encounter Kitty's ex-boyfriend Kevin at a restaurant. Divorced and bitter, Kevin confirms for Kitty that she was right to leave him years ago, but also that the man she truly wants exists only in her dreams.
The dream world delivers its cruelest blow: Lars tells Kitty her parents died when their airplane crashed into the Pacific on Halloween 1962. Kitty breaks down, insisting her parents are alive. Memories flood in with vivid clarity: Lars proposing at Rabbit Ears Pass; triplets born prematurely; Lars designing their house on Springfield Street; a nanny named Jenny, recommended by Frieda, who abused Michael by slapping him and silencing his screams. In the real world, Kitty picks up her parents, Tom and Claire, safely at the airport. Their joyous reunion fills her with relief. Her mother later tells her that a good companion is essential, but no person should be one's whole world. Kitty realizes that in the dream world, with her parents dead and Frieda estranged, she has been emotionally isolated.
Kitty confides in Frieda about the dreams. Frieda tries to ground her by pressing Kitty's hand against the warm shop window and leading her outside to smell the street. Kitty admits she fears falling asleep and being unable to return. Despite trying to stay awake, she drifts off. In the dream world, the family's housekeeper, Alma, reveals how Kitty blamed Frieda for recommending Jenny, walked out of the partnership, and left Frieda with nothing but debt.
A pivotal scene breaks the illusion. Standing outside Sisters', Kitty hears Patsy Cline's "Leavin' on Your Mind" playing inside, a song not yet released in October 1962, and sees books on the shelves that will not be published for months. She recognizes other impossible details: her parents arriving safely, Kevin's convenient appearance. She understands that the Kitty world is the fabrication, a comforting alternate life her grief-stricken mind constructed after her parents' deaths.
Katharyn wakes beside Lars and tells him, "This is the real world." She describes the imaginary life and her desire to write children's books; Lars encourages her. That morning, she has a breakthrough with Michael, drawing pictures beside words in a dictionary. Michael finds the word "anchor" on his own and recognizes it. She hugs him too tightly and he screams, but the progress is real.
Katharyn drives to Frieda's corporate headquarters for a tense reunion. Her full memory returns: She blamed Frieda for Michael's condition, walked out, and spent an inheritance to dissolve the partnership, leaving Frieda with nothing. Frieda rebuilt alone. Katharyn also realizes that Frieda's feelings went beyond friendship, that Frieda had wanted her as a life companion, and that Katharyn's departure broke her heart. Both women apologize and part with a fragile possibility of reconciliation.
Outside the building, Katharyn imagines her parents on the sidewalk. Her mother tells her to move grief from her head to her heart; her father says she will always have them, "just in a different form." She sits in her station wagon outside the children's school at 2:45 PM, waiting for dismissal. She envisions the ordinary evening ahead: snacks, homework, spilled milk, bedtime songs. The imaginary world of Kitty has faded. She accepts that this life, with its grief, its challenges, and its fragile hope, is where she belongs. She opens the car door and walks to the school entrance to embrace her children.