Aurora

The novel opens with a prologue describing the Carrington Event of 1859, when a massive coronal mass ejection (CME), a dense cloud of solar plasma, struck Earth and disrupted telegraph systems worldwide. Because telegraphs were the only significant electrical networks, society recovered quickly. The prologue warns that humanity has since become totally dependent on electricity and that a major CME strikes Earth roughly every 150 years. We are overdue.

On the morning of April 14, Norman Levy, an 88-year-old retired solar scientist living on Cayuga Lane in Aurora, Illinois, receives an urgent call from Perry St. John, a former student and researcher at the National Oceanic and Atmospheric Administration (NOAA). Perry reports that two massive solar flares have masked a third aimed directly at Earth. Norman runs predictive models, and every result confirms the incoming CME is Carrington-level. He gazes at his quiet street and reflects that everything is about to become local.

Aubrey Wheeler, a 38-year-old conference-business owner and Norman's neighbor, returns home to find her stepson Scott Wheeler, 15, watching frantic news coverage. Aubrey's marriage to Scott's father, Rusty Wheeler, a general contractor, collapsed due to his alcoholism and gambling, and when Rusty moved out, Scott chose to stay with Aubrey. In Silicon Valley, Aubrey's older brother Thom Banning, a billionaire robotics entrepreneur, activates his escape plan. He learns from Dr. Divya Singh of the Defense Science Board that the surge will destroy power infrastructure worldwide, that governments refuse to shut down their grids, and that recovery could take four to eighteen months. Thom's driver and fixer Brady, a former San Francisco cop, rushes him to an airfield, and the family flies to Sanctuary, a converted Titan II nuclear missile silo in Utah that Thom has spent $30 million renovating into a subterranean compound.

Aubrey and Scott rush to stock up on supplies but find their disaster preparations nearly nonexistent. Rusty gambles away his last $400 at a local casino and encounters Zielinski, a loan shark to whom he owes over $10,000. Zielinski's enforcer Espinoza pressures Rusty for payment, and Zielinski leaves a bloody extracted tooth on Rusty's dashboard as a warning. Thom calls Aubrey from his plane, urging her to come to Sanctuary, but she refuses. Their tense conversation hints at a complicated shared history, with Thom insisting he "owes" her.

The CME strikes Earth's magnetosphere at 3:37 a.m. The surge cascades through power grids, blowing transformers and melting power lines. Aubrey wakes to dead electronics and an eerie reddish glow. Neighbors emerge to witness spectacular aurorae. Norman stands in the street grinning with wonder. In the days that follow, Aubrey rescues Norman from carbon monoxide poisoning when his generator's exhaust vents back into his house. Norman's vintage shortwave radio brings news that equatorial countries were unaffected by the CME and are organizing relief efforts.

Thom sends Brady cross-country with $250,000 in cash for Aubrey. Brady survives an ambush at a refueling station in Nevada and arrives on Cayuga Lane, but Aubrey refuses the money, unwilling to accept her brother's charity or be indebted to him. When Rusty appears at the door, Aubrey mentions Thom's name and glances at the blue duffel bag of cash, allowing Rusty to deduce what is inside. That night, Rusty breaks in through storm-cellar doors whose biometric lock still accepts his fingerprint. Brady detects him and intervenes, but a passing police chase distracts Brady for a moment. Rusty stabs him with a hunting knife, steals the duffel bag, and kills Brady, abandoning the body in Brady's BMW at a hospital parking garage. The next morning, Scott finds Brady's revolver in the wet grass and hides it from Aubrey, who opposes firearms. He and his girlfriend Celeste drive to a remote site, fire practice rounds, and conceal the weapon.

A flashback reveals the secret binding Thom and Aubrey. When she was 15 and he was 18, they went joyriding with Thom's best friend Kyle Luedtke. Kyle climbed onto the car's roof at speed. Thom braked for a deer, and Kyle flew off and was killed. Aubrey told police she had been driving, taking the blame to protect her legally adult, intoxicated brother, whose predetermined genius their family had always prioritized over her. She received five years' probation. Their parents, who likely suspected the truth, died within months of each other, their mother of cancer and their father by suicide. Thom's survivor guilt fuels his compulsive need to protect Aubrey; her sacrifice feeds both her resentment and her refusal to accept his help.

Over the following months, Cayuga Lane transforms under Aubrey's leadership. She and Phil, an amiable neighbor with extensive agricultural knowledge, convert the block's front yards into vegetable gardens. Norman supervises the neighborhood's goats. Aubrey manages a water-rationing system. Scott and Celeste, whom Aubrey took in because Celeste's home life with her father Zielinski was dangerous, forage for firewood by dismantling abandoned houses. Aubrey enters a quiet relationship with Phil and finds herself physically and mentally transformed by purpose and labor.

At Sanctuary, Thom's planned community collapses. Residents defect. Jimmy Rutland, the ex-Major who serves as Sanctuary's security chief, departs with his militia, claiming masked marauders stole $3 million from the vault, though Thom suspects the militia took it. Ann-Sophie, Thom's wife, who never forgave him for an affair, expels him from the main house. Humiliated, Thom flees in a car.

Zielinski breaks Rusty's fingers to pressure him into extracting more cash from Thom. Rusty calls Thom on Brady's stolen satellite phone, claiming Brady returned and threatened Aubrey. Thom recognizes the lie but drives east toward Aurora with only $800 and no plan beyond reaching his sister. On the evening of Celeste's 16th birthday, Zielinski, Espinoza, and Rusty invade Aubrey's house, holding the household hostage and beating Scott and Celeste.

Thom arrives, and through silent hand signals at the door, Aubrey confirms three intruders. He retrieves Brady's Glock from the abandoned BMW, where he finds Brady's decomposed body and places Brady's Saint Christopher medal around his own neck. That night, he re-enters the house through the storm-cellar doors and bursts into the living room. Espinoza, whom Thom failed to account for, crashes through a door and knocks the gun from his hand, breaking his collarbone. A chaotic fight erupts: Aubrey shoves Rusty into the mantel, Celeste attacks her father Zielinski, and Scott races upstairs, retrieves the hidden revolver, and shoots Zielinski dead. Espinoza then shoots Rusty three times, saying Rusty never would have left them alone, and disappears out the back door.

Thom takes the revolver from Scott and fires three shots to put gunpowder residue on his own hands, establishing himself as the shooter. He insists the story must be that he killed both men, unwilling to let a 15-year-old bear the burden, echoing the age at which Aubrey sacrificed herself for him decades earlier.

Power returns by early November, and the official death toll exceeds 1.3 million. Norman dies before the restoration, leaving Scott his beloved 1957 Zenith shortwave radio with a note urging him to talk to people and watch the skies. For Aubrey, he leaves his annotated copy of Viktor Frankl's Man's Search for Meaning. At the memorial, Thom breaks down, telling Aubrey he never should have let her take the blame when she was 15. She tells him it did not ruin her: "We're OK, Tommy. We're OK now."