In the small Appalachian town of Dooling, West Virginia, a mysterious woman appears near a meth dealer's trailer, barefoot and surrounded by moths. She provokes a confrontation in which one man accidentally shoots the dealer; she then kills the shooter with the dead man's body. She ignites a piece of paper with a spark from her fingertips, tosses it into a nearby meth shed, and walks away from the explosion. Hours later, Sheriff Lila Norcross arrests her on Ball's Hill Road, bloody and wearing only a stolen shirt. The woman, who calls herself Evie Black, knows Lila's first name and makes cryptic remarks about her husband.
That same morning, a global pandemic begins. Women who fall asleep develop white, fibrous cocoons over their faces and bodies. They do not wake. If the cocoons are torn away, the women rouse in feral rage, attacking anyone nearby before collapsing back into sleep. News reports call the phenomenon Aurora. Within days, the vast majority of the world's women are unconscious and shrouded.
Lila arranges for Evie to be held at Dooling Correctional Facility for Women, where Lila's husband, Dr. Clinton Norcross, 48, serves as senior psychiatric officer. Clint interviews Evie and discovers she possesses impossible knowledge about his marriage and past. Evie sleeps without forming a cocoon and wakes normally, the only woman on earth known to do so. She controls rats and expels floods of moths from her mouth.
Lila carries a secret that strains the marriage from the other side. She has discovered that Clint fathered a daughter named Sheila Norcross with a woman from his past. Lila confirmed the connection after watching Sheila perform the same signature handshake that Clint taught their 16-year-old son Jared. Neither spouse raises the subject, even as the crisis forces them to work together.
The crisis rapidly destabilizes Dooling. Warden Janice Coates falls asleep after disgraced officer Don Peters secretly doses her coffee with Xanax. Peters, fired for sexually assaulting inmate Jeanette Sorley, who is serving time for killing her abusive husband, flees the prison. With the assistant warden absent, Clint becomes the de facto authority over more than a hundred cocooned inmates and a skeleton crew of four officers. Lila, running on amphetamines, manages the town's deterioration. When a deputy tears the cocoon from his wife's face and she kills him in feral rage, Lila shoots and kills the woman, the first person she has ever killed.
Evie calls Clint on a stolen cell phone and presents her proposition. She claims the sleeping women exist in an alternate version of Dooling called Our Place, where time moves much faster and the women are building a new community. If Clint keeps Evie alive until sunrise on Tuesday, the women will be given a choice: remain in their new world or return to the old one. If Evie dies, the portal closes permanently and all women will eventually sleep forever.
Frank Geary, 38, Dooling's animal control officer, whose love for his cocooned 12-year-old daughter Nana is matched by his volatile temper, steps into the power vacuum left by Acting Sheriff Terry Coombs, who has descended into alcoholism. Convinced that Clint is protecting Evie for unknown reasons, Frank assembles a posse of 20 men to take the prison by force.
Clint sends allies to steal weapons from the sheriff's station: NewsAmerica correspondent Michaela Morgan, Warden Coates's daughter whom Evie has supernaturally revitalized; lawyer Barry Holden; and Dr. Garth Flickinger. During their escape in a loaded RV, deputies fire on the vehicle. A bullet breaches the cocoon of Barry's eldest daughter Gerda, who awakens in feral rage and kills both Flickinger and a deputy before being shot. Barry dies from injuries sustained in the chaos.
In Our Place, Lila awakens in her ruined home and gradually assumes a leadership role. Over what feels like months, dozens of women arrive, including Coates, former inmates, and townswomen. They restore buildings, establish a school, and create a solar-powered electrical grid. Tiffany Jones, who formerly had a drug addiction and has found new purpose as a horsewoman, becomes Lila's close friend. When Tiffany dies after a complicated breech birth, her newborn son Andrew survives. The women discover the Amazing Tree, an impossibly tall, multi-trunked structure surrounded by exotic animals, including a white tiger and a fox that guides women between worlds. A split in the Tree's trunk serves as the passage.
Back in Dooling, escaped convicts Lowell and Maynard Griner obtain a bazooka and destroy the sheriff's station before positioning themselves above the prison. Frank's assault begins at dawn with armored bulldozers crashing through the fences. The battle is savage: Dynamite kills Officer Rand Quigley; bazooka shells destroy a wing of the prison, killing many cocooned inmates. Don Peters accidentally kills teenager Eric Blass, his own patrol partner. Evie reanimates dead inmates as defenders, and Angel Fitzroy, a violent inmate whom Evie has awakened, ambushes and kills Peters. Officer Vanessa Lampley tracks the Griners and kills Lowell, wounding Maynard, before succumbing to sleep. Terry Coombs, despairing, kills himself.
Frank and his remaining men reach A Wing, where Clint, Jared, Michaela, elderly volunteer Willy Burke, and Angel form a human shield before Evie's cell. Evie tells the men to kill her, claiming this will awaken every woman on earth. Clint refuses, arguing that her death would permanently close the portal. When Willy collapses from a heart attack, Clint demands Evie save him. She kisses the old man and breathes life back into him. Shaken by this demonstration, the attackers lower their weapons. Evie agrees to return to the Tree and let the women vote.
In Our Place, Evie presents the choice: stay or return. Elaine Nutting, Frank's estranged wife, has independently tried to burn the Tree with kerosene, believing the new world is safer for women. Jeanette Sorley, sent through the passage by Evie, confronts Elaine and argues that the women deserve to choose for themselves. A white tiger stamps out the small fire Elaine's lighter has started. Lila arrives, mistakes Jeanette for a threat, and shoots her. Jeanette dies asking Elaine to remember her son Bobby.
The women vote nearly unanimously to return, motivated by love for their children, desire for ordinary life, and gratitude toward the men who defended the prison. They enter the Tree in pairs and awaken from their cocoons worldwide. Baby Andy, born in Our Place, passes through in the arms of Blanche McIntyre, Coates's secretary. The Tree dies as the last women depart. Lila buries Jeanette before crossing over.
In the aftermath, Lila resigns as sheriff, haunted by having killed Jeanette, a Black woman, and tormented by whether she would have given a white woman more time. She adopts baby Andy and works at a daycare center named for Tiffany Jones. Clint and Lila separate, though neither files for divorce. Frank enters anger management therapy and accepts the end of his marriage. Elaine sends letters to Bobby Sorley, Jeanette's son, describing his mother's bravery; Nana Geary includes drawings, and the children become pen pals. On Thanksgiving, Clint and Frank share a civil drink in a bar, reflecting on loss. In the novel's final scene, Lila hikes to the clearing where the Tree once stood, carrying Andy. She calls out for Evie, but only a single moth, landing on her hand, answers.