On the eve of nuclear war, the President of the United States agonizes in the White House Situations Room as military advisors pressure him to raise the nation's defense readiness. He reluctantly authorizes Defcon Three, a heightened nuclear alert level. Within hours, Soviet and American missiles fill the sky, and civilization collapses in minutes.
The novel follows several characters whose lives converge across the years that follow. In New York City, a homeless woman known as Sister Creep wanders Times Square, preaching about the end of the world. In Kansas, Josh Hutchins, a 35-year-old professional wrestler who performs under villainous aliases like "Black Frankenstein," stops at a roadside grocery run by PawPaw Briggs after his car overheats. Nine-year-old Sue Wanda "Swan" Prescott and her mother, Darleen, arrive at the same store minutes later, fleeing an abusive boyfriend. Swan is an unusual child: She grows extraordinary gardens in trailer park dirt and hears a "hurting sound" when living things are damaged.
Nuclear missiles erupt from hidden silos in the cornfield surrounding the grocery store. Josh drags Swan, Darleen, and PawPaw into the basement as a tornado of fire obliterates the landscape, burying them under tons of earth. In Idaho, Earth House, an underground survivalist complex, is shaken apart by the shock waves of a malfunctioning warhead. Colonel James "Jimbo" Macklin, a decorated Vietnam veteran who serves as the complex's figurehead, is trapped with his right hand crushed in a rock fissure. Roland Croninger, a 13-year-old obsessed with a medieval computer game called King's Knight, amputates Macklin's hand with a meat cleaver and cauterizes the stump. Roland attaches himself to Macklin, envisioning himself as a knight serving a king.
Deep beneath Manhattan, Sister Creep survives the blast in a drainage tunnel and emerges into a devastated city. She encounters a shape-shifting entity that feeds on human suffering and regards the nuclear holocaust as its celebration. The creature rips a crucifix from her neck and sets a theater ablaze.
In the buried basement, Darleen dies of radiation sickness. PawPaw's corpse spontaneously sits up, its eyes bursting into flame, and speaks: "Protect the child," before immolating into white ash. Josh accepts the commandment. He and Swan dig out through a gopher hole and emerge into a featureless wasteland. Swan picks up her scorched Cookie Monster doll, points them in a direction, and starts walking.
Trekking through the ruins with other survivors, Sister discovers the glass ring on Fifth Avenue: a circle of glass with five spikes embedded with hundreds of jewels fused by the blast from the inventories of Tiffany's, the Steuben Glass shop, and other stores. The ring pulses with the heartbeat of whoever holds it, generates visions of comfort, and enables Sister to understand unfamiliar languages. A man calling himself Doyle Halland, apparently a priest from Jersey City, joins the group but reveals himself as the shape-shifting entity by murdering two companions and demanding the ring. When he touches it, the jewels turn dark. Sister gouges a glass spike into his forehead and escapes. The entity vows to find her. When Sister peers into the ring, she experiences "dreamwalking," entering vivid visions of distant places: a barren plain with a Cookie Monster doll, a hand emerging from a hole in the ground. She realizes the ring is leading her toward someone and begins a years-long search with Paul Thorson, a bitter poet who joins her in Pennsylvania.
Macklin and Roland reach the Great Salt Lake, where they seize a survivors' encampment by force and organize it into military brigades, founding the Army of Excellence (AOE), a fascistic force that grows to dominate the western territories.
Seven years pass. The world is locked in perpetual winter. Many survivors develop "Job's Mask," a condition in which hard, scablike growths slowly encase the face and skull. Swan, now 16, travels with Josh and Rusty Weathers, a cowboy-turned-circus-clown, in a wagon called the Travelin' Show, performing magic and wrestling for food. Swan's face is almost sealed by Job's Mask. A fortune-teller named Leona Skelton reads Swan's tarot cards along the way, predicting her destiny and warning of a dark opposing force. In Matheson, Kansas, the group is captured by Alvin Mangrim, a violent asylum escapee who rules a murderous kingdom. Josh fights through a deadly gauntlet to free them, but Leona is killed in the escape.
When Swan touches a dying apple tree on a Missouri farm, it explodes overnight into white blossoms. She reaches Mary's Rest, a squalid settlement, where Josh befriends Glory Bowen, a seamstress who shelters them and becomes a source of warmth and steadiness for him during the town's darkest days. Swan plants dried corn kernels in the frozen field; pale green cornstalks sprout within hours. Rusty is killed defending Swan from the entity, who has been lurking nearby in disguise. Swan's Job's Mask cracks open, revealing a beautiful face with flame-colored hair, the true face Leona once predicted. When Sister, who has followed the glass ring's visions to Mary's Rest, places the ring on Swan's head, it fits as a crown, and golden light engulfs Swan's body. Sister recognizes the crown has always belonged to Swan.
The entity steals corn from the settlement and drives north to the AOE, now 3,000 soldiers. Calling himself "Friend," the entity takes command and directs the army toward Mary's Rest. Swan rallies the townspeople to build a wall of logs glazed with ice and dig defensive trenches. Robin Oakes, a 17-year-old leader of orphaned boy bandits who has fallen in love with Swan, fights alongside the defenders. The army breaches the walls, and Swan, Sister, Josh, and Robin are captured.
Friend forces the army east to Warwick Mountain in West Virginia, guided by Brother Timothy, a fanatical prisoner captured from a rival religious army who claims to have found "God" in an underground complex. The figure is the President, who survived the crash of his Airborne Command Center and has lived in the complex for seven years after his two original companions died or departed. He believes Evil has won and activates Talons, a doomsday system that will fire 60 nuclear warheads into the polar ice caps to flood the world. He locks everyone inside the chamber.
Friend kills the President. Roland shoots Sister when she fights for the gun. Macklin, in a final act of redemption, drives his nail-studded prosthetic hand into Roland's heart. With seconds remaining, Swan types "Amen" on the keyboard, recognizing that the codeword to halt the system's coded sequence, drawn from T.S. Eliot's
The Waste Land, is the word that ends all prayers.
Sister, mortally wounded, asks to be carried to the mountaintop. For the first time in seven years, the clouds part and sunlight streams through. Sister dies in the warmth. Swan throws the Talons key off the mountain, vowing "Never again."
They escape through the disintegrating AOE camp. Paul Thorson, left for dead after the battle, uses his last bullet to kill Mangrim before dying in the returning sunlight. Swan confronts the entity one final time, telling him she forgives him. He disappears beneath a mob of fighting soldiers.
Josh drives them west to a mountain valley where a farmer is planting beans. He tells Swan she must begin her work here, field by field. He returns to Mary's Rest, where Glory Bowen waits for him. Robin stays with Swan, and Sheila Fontana, a woman held in the AOE camp who helped them survive captivity, joins their growing group.
In an epilogue spanning years, Josh walks home to find Glory running toward him in the spangled dress she wore each day hoping for his return. Swan travels the country restoring orchards, cornfields, and forests. She and Robin have twins named Joshua and Sister. Settlements rebuild, schools teach the lesson "Never again," and future generations pass Swan's story to their children, always beginning: "Once upon a time . . ."