The novel opens in 2079, where Fiona Skinner, a 102-year-old poet, addresses an audience at her first public appearance in 25 years. Her second husband, Henry, sits beside her. A young woman named Luna asks about the inspiration behind Fiona's famous work,
The Love Poem. Fiona begins telling the story of her family: four children and a period of crisis she calls "the Pause."
In 1981, in the middle-class Connecticut town of Bexley, Ellis Avery Skinner, a 34-year-old dentist, dies of sudden cardiac arrest. He leaves behind his wife, Antonia (called Noni), and four children: Renee (eleven), Caroline (eight), Joe (seven), and Fiona (four), the narrator. At the funeral reception, Joe seizes a fireplace poker and rampages through the house, smashing dishes, furniture, and photographs. The siblings surround and embrace him. Fiona reflects that this moment marks each sibling's assumption of a lifelong obligation of love toward Joe, one none of them will fully fulfill.
Financial pressures force the family into a smaller house. Noni retreats to her bedroom for two to three years, a period the children call "the Pause." Renee, still a child, assumes a quasi-parental role: forging signatures, cooking meals, and keeping the household running. Joe discovers a pond in nearby woods that becomes the children's refuge and teaches Fiona to swim. They befriend Nathan Duffy, a quiet boy who develops feelings for Caroline, and Ace McAllister, a wealthy, aggressive child whose relationship with Joe shifts to admiration after Joe rescues him from a dangerous fall.
The Pause ends after a harrowing incident. Thirteen-year-old Renee is attacked by a man who follows her home. Joe fights the man off with his spiked baseball cleats. Eventually, Joe's coach discovers the children walking along a highway, drives them home, and sees the household's disarray. Noni's sister-in-law arrives to restore order, and Noni finds a job. She returns to parenting, reinventing herself as a feminist who lectures her daughters about independence while exempting Joe from scrutiny.
In 1992, all three older siblings leave home: Joe for college on a baseball scholarship, Renee for medical school, and Caroline for Kentucky with Nathan, whom she has secretly married. Fiona, 15, dreads being left alone with Noni.
In autumn 2004, Caroline reveals that Joe's supposed knee injury was a cover story. Joe was expelled from the team after a fraternity party involving massive quantities of alcohol and drugs; a girl nearly died from alcohol poisoning. Renee negotiated academic probation with administrators, shielding Noni from the truth. Joe told Renee their dead father had appeared to him. Caroline discloses that Renee is now worried about Joe's drinking, cocaine use, and a recent cardiac episode. Fiona insists Joe is fine and persuades Caroline to drop the idea of an intervention.
At Joe's engagement party, Fiona reads a poem for Joe and his fiancée, Sandrine Cahill. Joe talks and laughs loudly during the reading until the crowd ignores her. Renee, who arrives late from an ER shift where she met a furniture maker named Jonathan Frank, confronts Joe on the balcony about his substance use. He dismisses her, insisting she is not his mother. Stung, Renee decides to release herself from responsibility for her brother.
Weeks later, Joe is fired and punches his boss. Sandrine leaves Joe for Ace McAllister. Stripped of his job, fiancée, and social circle, Joe moves to Miami, where he meets Luna Hernandez, a 25-year-old Nicaraguan-American bartender whose younger sister disappeared years earlier. They begin a relationship. Joe calls Fiona and tells her he knows she writes an anonymous sex blog called
The Last Romantic, saying it cheapens her. Furious, Fiona hangs up. This is their last conversation.
After a night of drinking, Joe falls in his kitchen and hits his head on the marble floor. Luna finds him apparently sleeping and lies beside him but eventually leaves. Three days later, police inform Luna that Joe died from a subdural hematoma, a type of brain bleed.
The three sisters travel to Miami to clean Joe's apartment. They discover a Tiffany engagement ring and a Polaroid of Joe and Luna, realizing he intended to propose. Caroline wants to give Luna the ring. Renee resists but consents, then drives alone to the restaurant, where she shouts accusations at the hidden Luna before collapsing in shame, recognizing that she, too, walked away from Joe.
The sisters fracture. Fiona searches for Luna, spending thousands of Caroline's dollars on a clairvoyant and a private investigator with no results. Caroline confronts Fiona, accusing her of irresponsibility. They do not speak for five years.
During the estrangement, each sister follows her own path. Fiona stops the blog and begins composing
The Lasts, a series of poems documenting the final details of Joe's world that becomes her first published book. She starts a relationship with Will, a man she encountered through the blog. Caroline falls into a deep depression before questioning whether she loves Nathan. Renee and Jonathan, now her partner, travel internationally while she performs surgeries in rural clinics. She treats Melanie Jacobs, a young woman with cystic fibrosis who dies after surgery. Melanie's husband later tells Renee that Melanie wanted to donate her frozen eggs to her.
After five years, Caroline arranges a reunion and announces she has left Nathan. The sisters reconcile and plant a lilac tree for Joe. Years pass: Caroline pursues acting, Fiona marries Will, and Renee, at 52, uses Melanie's eggs and Jonathan's sperm to become pregnant. Jonathan gradually withdraws and leaves.
While preparing for a conference in Seattle, Fiona discovers Luna living under a new name on an island in Puget Sound, Washington. Luna is married to Dima, the bartender from her old restaurant, and has a toddler and another child on the way. Fiona visits and offers the engagement ring, but Luna refuses, saying that time is behind her. Then a teenage boy enters the room, and for one blazing instant Fiona believes he is Joe: the same height, blue eyes, dark hair. The boy is Rory, Luna's son. Fiona calculates the timeline and understands that Rory is Joe's child. She decides not to tell her sisters, fearing the Skinners would consume the boy with their fierce love. She tells Luna to keep the ring for Rory.
Renee gives birth to Jonah Ellis Avery Skinner via emergency C-section. Jonathan arrives unexpectedly, holds the baby, and their reconciliation begins wordlessly. Fiona buries the secret of Rory.
The 2079 frame concludes as the young Luna helps Fiona off the stage during an evacuation drill. Henry drives Luna partway home, and Fiona reveals everything, including the secret she kept. The diamond ring hangs on a chain around Luna's neck, linking her to Joe and Luna Hernandez. Fiona narrates the futures and deaths of her loved ones across the coming decades, then corrects her earlier framing: This is not a story about the failures of love but about real, imperfect love. When the lights go out and we sit waiting in the dark, we reach for the ones we love.