Sheriff Holston voluntarily locks himself in the holding cell to be sent out to cleaning.

Mayor Jahns and Deputy Marnes descend the silo to recruit a mechanic named Juliette as the new sheriff.

Bernard Holland, head of IT, clashes with Mayor Jahns and refuses to approve Juliette's appointment as sheriff.

Mayor Jahns collapses and dies near the nursery after drinking from her poisoned canteen.

As new sheriff, Juliette begins obsessively investigating the files that drove Holston and his wife to cleaning.

Juliette and Walker discover together that IT deliberately engineers the cleaning suits to fail.

Bernard sends Juliette back to Mechanical and then sentences her to cleaning.

Juliette survives the cleaning by wearing a suit secretly rebuilt with durable replacement parts from Supply.

Juliette refuses to clean the cameras and walks over the hill, vanishing from the silo's camera view.

Bernard rushes to a secret server and phones Silo 1 to report Juliette's disappearance over the hill.

Knox leads Mechanical and Supply workers in an armed assault up the silo staircase toward IT.

Juliette forces her way into the abandoned Silo 17 and discovers a lone survivor she names Solo.

Lukas confronts Bernard about the murder of Juliette's former lover George Wilkins and is sentenced to cleaning.

Peter Billings rebels against Bernard's orders and sends Bernard into the airlock's cleansing fire instead of Lukas.

Juliette is elected mayor by write-in ballot and vows to govern through truth rather than deception.

Wool opens when Sheriff Holston voluntarily submits to cleaning, an act of grief and curiosity that sets the entire novel in motion. Mayor Jahns and Deputy Marnes travel deep into the silo to recruit a mechanic named Juliette as his replacement, drawing her into the dangerous politics of the upper levels. After Jahns is assassinated by Bernard's poison, Juliette becomes sheriff and investigates the secrets that drove Holston's wife to cleaning, eventually deducing that IT's cleaning suits are engineered to fail. Bernard sentences Juliette to death, but she survives by wearing a secretly rebuilt suit and vanishes beyond the silo's cameras, triggering a violent uprising between Mechanical and IT. The novel resolves when Bernard is killed by a rebel's hand and Juliette returns to be elected mayor, vowing to govern through truth rather than deception.

The headline events that take Silo 18 from Holston's cleaning to Juliette's election as mayor.

Holston watches through his holding cell screen as Allison goes out to cleaning and collapses on the hill.

Jahns and Marnes stop at the nursery and speak with Dr. Nichols, Juliette's estranged father, about her history.

Juliette reluctantly agrees to become sheriff in exchange for a power holiday to repair the silo's failing generator.

Juliette completes unprecedented repairs on the main generator and the mechanics cheer as it runs quietly.

Juliette meets Lukas in the empty late-night cafeteria and he points out the stars on the screen to her.

Juliette discovers Deputy Marnes has hanged himself in his apartment, leaving a note reading 'It should have been me.'

Scottie is found dead in an apparent suicide shortly after showing Juliette an IT program that generates fake outdoor views.

Walker leaves his workshop for the first time in forty years to tell the mechanics the cleaning suits are rigged to fail.

Knox delivers a rousing speech to skeptical Supply workers, convincing them to join Mechanical's rebellion against IT.

Bernard leads Lukas through a hollow server rack into a secret underground bunkroom hidden beneath the IT floor.

Solo shows Juliette a photograph of a grain silo and explains the underground silos were built to preserve humanity.

Walker and Shirly repair a salvaged radio in the generator room and begin intercepting transmissions from other silos.

Juliette dives into the flooded lower levels of Silo 17 to fix the pump and barely escapes drowning.

Juliette discovers wild children hiding in the Silo 17 farm, including a teenage mother with an infant.

Solo contacts Juliette by radio to report that her pump repairs have caused the floodwaters in Silo 17 to recede.

Many of Wool's most important moments happen just outside the headline action, revealing the human texture of silo life. Holston watches his wife Allison's cleaning from the holding cell in a haunting flashback, while Jahns learns about Juliette's painful past from her estranged father before ever meeting her. As Juliette settles into the role of sheriff, she meets Lukas in the late-night cafeteria, begins a tentative romance, and is rocked by the suicide of Deputy Marnes. Walker's dramatic emergence from his workshop to announce the truth about the cleaning suits galvanizes Mechanical, and Knox's rousing speech persuades Supply to join the rebellion. In Silo 17, Juliette faces a series of escalating survival challenges — near-drowning, isolation, and the discovery of wild children — while back home, Walker and Shirly repair a radio and first hear another silo's voice. The novel closes quietly with Solo reporting by radio that Juliette's pump repairs are holding and the floodwaters are falling.

The supporting scenes that built Juliette's world, sparked the rebellion, and shaped her survival in Silo 17.

Allison tells Holston in her holding cell that nothing he sees is real and promises to survive and return.

Holston cracks open his helmet outside and discovers the world is truly desolate, finding Allison's body beside him.

Bernard secretly fills Jahns's canteen with poison while she and Marnes rest at IT on their way back up.

Bernard declares himself acting mayor and installs Peter Billings as the new deputy sheriff after Jahns's death.

Scottie shows Juliette an IT program that can fabricate convincing fake outdoor views, then begs her to delete the files.

Juliette receives Scottie's posthumous message revealing that the deceptive visor display measures exactly eight inches by two.

Juliette realizes as she steps into the airlock that her helmet's visor matches the dimensions of the fabricated display.

Bernard formally offers Lukas the position of his shadow and chosen successor as the next head of IT.

Bernard shows Lukas the map of all fifty silos and a page in the Order reading 'In Case of a Failed Cleaning: Prepare for War.'

Knox and McLain are both killed when IT opens fire on the advancing workers from behind a barricaded conference table.

Lukas defies Bernard's direct orders and begins secretly communicating with Juliette through the forbidden server transmitter.

The voice from Silo 1 tells Lukas that the silo's founders deliberately caused the apocalypse to preserve their way of life.

Juliette reaches Mechanical by radio from Silo 17 and begs her friends to stop fighting, whatever it takes.

Juliette walks across the toxic landscape from Silo 17 to Silo 18 wearing a homemade cleaning suit to rescue Lukas.

Juliette and Lukas reunite inside the silo and share their first kiss after her return from Silo 17.

Wool's deepest story is one of truths uncovered and decisions made that cannot be taken back. Allison's whispered conviction to Holston — that nothing they see is real — plants a seed that outlasts her, and Holston's own moment of fatal discovery outside confirms the scale of IT's deception. Bernard's quiet poisoning of Jahns's canteen and his swift consolidation of power afterward reveal how ruthlessly he guards the silo's order. Juliette inches toward the same forbidden knowledge, learning about the fabricated visor views and finally recognizing the deceptive display's dimensions at the very moment she steps into the airlock. As the rebellion collapses around them, Lukas secretly bridges the two silos through the forbidden transmitter, even as the voice from Silo 1 confirms that the founders deliberately caused the apocalypse. The novel turns on Peter Billings's unexpected revolt against Bernard, an act that finally breaks the chain of deception and allows Juliette to return as a leader who chooses truth.

The hidden truths, pivotal discoveries, and defining choices that changed everything in the silo.