59 Minutes

The novel opens with a factual preface detailing the projected devastation of nuclear weapons on populated areas, including a 1,200-kiloton bomb striking central London and Russia's Poseidon nuclear torpedoes generating radioactive tsunamis on coastal cities. The author states that while the story is fictional, these nuclear details are not.

On a Friday evening in November, Carrie Spencer, a woman in her early thirties who works at a London ad agency, walks through the South Bank toward Waterloo Station, eager to get home to her partner Emma, their three-year-old daughter Clementine, and Pepper, their elderly landlord and family friend. At 5:01 p.m., every phone in the station shrieks with an emergency alert: A nuclear missile is headed for southern England, with 59 minutes until impact. Every screen goes black, displaying: "SEEK IMMEDIATE SHELTER."

Simultaneously, on Dartmoor in Devon, Frankie, a 36-year-old dried-flower studio owner from Manchester, arrives at a rented holiday cottage with her boyfriend Otis. She has just told him she is pregnant when the same alert reaches their phones. A third storyline introduces a woman identified only as Mrs. Dabb, home alone in an isolated Dartmoor cottage on the anniversary of a devastating personal loss. Her 13-year-old daughter Bunny fails to get off the school bus, and calls to other parents reveal Bunny forged a note to leave school early. Mrs. Dabb discovers a hidden phone charger confirming her daughter owns a secret cell phone.

At Waterloo, armed officers seal all exits. Carrie resolves to reach her family on foot, remembering that her agency once filmed a commercial in the station's disused tunnels. She creates a diversion and slips through a hidden staff door into the pitch-black passage. A 13-year-old schoolgirl named Grace, who followed her from the concourse, catches up, and together they walk the tracks until they find a maintenance exit and emerge barely a hundred meters from where they started.

Frankie and Otis drive to the nearby village of Chagford to buy supplies. The orderly queue outside the shop collapses into chaos. While Frankie waits outside, a muddy pickup truck pulls up. Three brothers in balaclavas, Jimmy, Ashley, and Sandy Curtiss, who call themselves the Devon Militia, order her inside at gunpoint. When she refuses, Sandy forces her into the truck, which speeds away before Otis can reach her. A terrified teenage girl named Juno, also taken captive by the brothers, is already in the back seat.

Mrs. Dabb drives through the fog to question Bunny's best friend Jasmine, who reveals that a relative of Bunny's biological father approached Bunny outside school and gave her the phone. Mrs. Dabb insists Bunny does not have a father. She drives to the Curtiss family compound but Bunny is not there, so she races home hoping Bunny has returned.

Above ground in London, Carrie and Grace navigate a city in chaos: Cars crash, people loot shops, and overwhelmed police struggle to man roadblocks. When the power cuts out, a man drags Grace into an alleyway and pulls a plastic bag over her head. Carrie rescues her by startling the attacker with a thrown piece of broken bottle. She delivers Grace safely to her mother Beverley on Elm Walk, then runs toward home.

Inside the truck, Frankie and Juno spot a car following them, possibly Otis. The car rams the truck, which crashes into a tree. Jimmy flies through the windshield and Sandy is killed. Frankie and Juno escape, and Frankie finds Otis unconscious in his crashed Mercedes. She discovers a nearby cottage where Janet Spencer, Carrie's mother, lets her in and treats her wounds. Janet's cellar is stocked with water and supplies. Frankie agonizes over leaving Otis outside but has no time to retrieve him. Then a new alert arrives: The missile threat has been averted. There was no missile.

Mrs. Dabb arrives home to an empty cottage and is near collapse when loud knocks come at the back door. Bunny rushes inside, sobbing apologies.

In the final minutes of the countdown, Carrie sprints through Prince's Square when a deafening roar fills the sky. She is knocked down, blinded and deafened by debris and fire. Someone grabs her and falls on top of her. Unable to see or hear, she fights them off, strikes them with a brick, and stumbles to her front door. Pepper meets her with the averted-threat message. Clementine is safe upstairs. But Emma is not there. Pepper writes on a notepad what happened: A helicopter crashed in the communal garden. Emma saw Carrie fall from the window and ran outside to help. Carrie, blinded and deafened, did not recognize Emma and struck her with the brick. Carrie rushes outside and finds Emma's body in the garden.

At Janet's cottage, Ashley Curtiss arrives injured and desperate. Janet lets him in despite Frankie's protests. When Ashley realizes his brothers are dead and the threat is over, he grows agitated and takes the gun Frankie had carried from the truck. Janet, trying to stop him from shooting, reveals that he has a three-year-old daughter named Clementine. She shows him a photograph of Carrie, Carrie's partner, and the child, explaining that Carrie is her daughter and that Ashley met Carrie at a pub years earlier. Startled by a bang on the front door, Ashley fires and kills Janet. Juno returns with local men who subdue him.

The novel's third part, set ten years later, reveals a structural twist: Mrs. Dabb is Carrie. Clementine, now 13, is called Bunny. After the alert, Carrie moved to Dartmoor, changed their surname to Dabb, and settled in Janet's cottage. The anniversary she dreads is that of Emma's death, which coincides with the day of the alert. Bunny confesses she used the anniversary to visit Ashley at a prison memorial service, having discovered his identity through a DNA test facilitated by Ashley's mother, Mrs. Curtiss. A siren announces Ashley's escape from prison; he followed Bunny home and hid on the cellar stairs before confronting her in her bedroom. Carrie positions herself between Ashley and Bunny. He tells Bunny her goodness came from her mother, then surrenders to police.

Interleaved with the ten-year-later scenes are chapters covering the aftermath. The death toll climbs past 2,000 from car accidents, violence, and deaths by suicide. Frankie stays at the hospital with Otis, who has a moderate brain injury. Investigations subsequently determine that the false alert was the work of foreign state-sponsored hackers. Emergency sentencing laws offer reduced terms to those who plead guilty to crimes committed during the 59 minutes, but Ashley refuses. One year after the alert, Carrie and Frankie independently visit the memorial wall in St. James's Park. Frankie recognizes Carrie from Janet's photograph and introduces herself, inadvertently revealing that Janet told Ashley he was Clementine's father. Carrie begs Frankie never to repeat this, and Frankie agrees.

In the epilogue, set on New Year's Day 2036, Carrie and Bunny prepare to leave Dartmoor for Brighton, the seaside life Emma always wanted. Carrie has forgiven Ashley's mother, the hackers behind the false alert, and even Ashley himself, who receives regular letters from Bunny. Sitting in the garden at dawn, Carrie imagines Emma beside her and tells her everything about their daughter and how she would live it all again for the time they had. In her final act before the movers arrive, she decides to forgive herself.