Antonia Vega, a recently retired literature professor, is to meet her husband, Sam Sawyer, a beloved local doctor, at a favorite restaurant to celebrate her retirement. Sam never arrives. He has died of a ruptured aortic aneurysm while driving up the mountain to their home in rural Vermont. Months later, Antonia still cannot comprehend how someone she loved is now nothing but dust.
In the wake of Sam's death, Antonia clings to routines, taking only small "sips of sorrow" to avoid being overwhelmed. She draws on a lifetime's storehouse of literary quotations for comfort, though the lines increasingly fail her. Her three sisters check in regularly: Izzy, the eldest, a former therapist prone to grandiose plans; Tilly, the practical middle sister who lives outside Chicago; and Mona, the youngest, also a therapist. Together the four are known as "the sisterhood," bound by fierce loyalty and constant bickering. Tilly reports growing worry about Izzy, who has left her practice, stopped her medications, and is spending recklessly while selling her house near Boston.
Antonia's widowhood is disrupted when her dairy-farmer neighbor, Roger, sends Mario, a young undocumented Mexican worker, to clean her gutters. Mario asks Antonia to help him contact his
novia, or girlfriend, Estela, who has crossed the US-Mexico border but is being held by coyotes, or smugglers, in Colorado who demand more money for her release. Antonia hides Mario when a sheriff's cruiser passes, something Sam would have done without hesitation. She persuades Roger to let Estela stay on his farm for a week and buys Estela's bus ticket. Hoping distance will free her from a situation she cannot handle, Antonia resolves to visit Tilly for her sixty-sixth birthday.
In Illinois, Tilly proposes that the sisters stage an intervention for Izzy. Then Izzy leaves a voicemail on the phone of Tilly's husband, Kaspar: She is driving to Illinois to surprise Antonia, calling from a stranger's cell because she has lost her own phone. After this message, the sisters cannot reach her. Izzy does not call on Antonia's birthday morning, an unprecedented absence, as she has always been the first to sing "Las Mañanitas," a traditional Mexican birthday song. At a tense birthday dinner, the sisters all weep together.
They file a missing persons report, post profiles on registries, and call hospitals and highway police, learning that Izzy was fired from her practice for blurring professional boundaries. They hire a private investigator. After over a week with no word, they disperse: Mona to Boston, Tilly to post flyers along Izzy's possible route, and Antonia home to Vermont.
Returning to her garage, Antonia finds a frightened, very pregnant girl nesting among patio cushions. It is Estela, who arrived safely but has been cast out by Mario. Mario left Mexico nearly two years ago, and the baby cannot be his. Sobbing, Estela confesses that a powerful married man in her village got her pregnant and then arranged her journey north to be rid of her. Antonia settles Estela into the guest room and confronts Mario, urging compassion, but he refuses, invoking his honor and hurling a slur that Antonia forbids. His coworker José promises to reason with him.
Meanwhile, Mona calls with news: Izzy's friend Maritza saw Izzy's handbag stuffed with cash and medication bottles before the disappearance, Izzy had emptied her bank account, and her cell phone, left behind at a house in Athol, Massachusetts, ran out of charge, explaining why the sisters could never reach her. Antonia arranges prenatal care for Estela through Dr. Beth Trotter, Sam's former colleague, and deflects a visit from Sheriff Boyer after a neighbor reported someone entering her garage.
Antonia drives to Athol to join the search. During an interview with a local investigator, her phone rings: It is Izzy, calling from a rest stop in Gary, Indiana, indignant about a bad photo on her own missing-persons poster. Antonia keeps Izzy on the line by describing Estela's plight, appealing to Izzy's empathy, and extracts her location. The investigator contacts state police, who stop Izzy on the highway. At almost the same moment, Beth calls: Estela could give birth any day, and because she is an undocumented minor, the hospital must notify child protective services and immigration enforcement unless an expedited guardianship is arranged.
Back in Vermont, Sheriff Boyer warns Antonia that federal agents are planning an immigration raid in the county. She takes Estela to her own house for safety, leaves the girl with Beth, and drives to Boston for Izzy's intervention. At a hotel, the sisters meet with Dr. Kim Campbell, a psychiatrist who frames a residential stay at Liberty House as a collaborative evaluation, including brain scans to check for Alzheimer's risk, a terror for Izzy given their mother's dementia. Tilly falls to her knees begging; Mona and Antonia follow. Dr. Campbell tells Izzy, "I'd say your sisters really love you." Izzy consents with a military salute that fills Antonia with dread. Earlier, Izzy told her, "I hear your words, but they don't come through to me," a line Antonia cannot shake.
Over the weekend, Beth texts that Estela is in labor. Izzy insists Antonia leave to be with the girl. Antonia departs Sunday. Monday morning, Mona calls in distress: Izzy swallowed every pill she could find during the night, including medications stolen from her sisters' suitcases. A young emergency room doctor tells Antonia that Izzy's brain damage is irreparable; she is being kept alive only by machines. Antonia asks the doctor to hold the phone to Izzy's ear but cannot find a single word to say, the moment she has always dreaded, when words fail completely.
The weeks after Izzy's death blur together: arrangements, the coroner's investigation, cremation. Antonia picks up the ashes alone and drives them home. Estela gives birth to a healthy girl but initially refuses to bond with the baby. Antonia decides she cannot walk away. In mid-May, Estela and baby Marianela move into Antonia's house. Estela has named the baby after Mario, a choice that, along with the infant's resemblance to him, gradually softens his resistance; he begins visiting regularly. Through their shared care of Estela, Antonia and Beth grow close. Beth tells Antonia it is fine not to take on permanent guardianship if the certainty is not there.
On September 11, Antonia drives Mario, Estela, and Marianela to Boston for Estela's passport at the Mexican consulate, then to Logan Airport for their flight home to Chiapas, Mexico. With Antonia's financial help, Mario plans to open a repair shop; Estela will return to school; they plan to marry. Antonia has promised to attend the wedding and scatter Izzy's ashes. A state trooper pulls them over for speeding. Mario has only a passport with no US visa; Estela has only a consular ID. Estela sobs, terrified her baby will be taken. A second cruiser arrives: Sheriff Boyer. He speaks with the trooper, returns to Antonia's window, and hands back their documents. "You're good to go," he says.
In the epilogue, Antonia attends the final session of Beth's Zen workshop series. A teacher demonstrates kintsugi, the Japanese art of repairing broken pottery with gold lacquer. He deliberately smashes a serving platter, then reassembles it with gold-laced adhesive, making the cracks visible rather than hiding them. Antonia closes her eyes and envisions all the broken things in her life being reassembled with golden seams of poetry and story. The teacher holds up the mended platter: "Is beautiful," he concludes, a final image of a fractured life repaired but bearing its scars in gold.