Orlean visits Central Library with Ken Brecher, who opens a book and reveals it still smells of smoke from the 1986 fire.

A fire alarm sounds at Central Library but is dismissed as faulty, and patrons calmly exit leaving their belongings behind.

Flames erupt inside Central Library, temperatures climb to 2,500 degrees, and book covers begin combusting and popping off shelves.

The Central Library fire is finally extinguished after burning for seven hours and 38 minutes.

A book conservator warns that water-damaged books must be frozen within 48 hours or mold will destroy them permanently.

Hundreds of volunteers respond to radio announcements and pack over 50,000 boxes of damaged books for transport to fish warehouse freezers.

Fire Chief Manning publicly declares the Central Library fire was arson and describes a suspicious young blond man seen near the flames.

Orlean travels to the Peak family home in Hemet and interviews Harry's sister Debra to understand who Harry Peak really was.

A woman named Melissa Kim calls the police tip line, identifying Harry Peak as someone who claimed to be present at the fire.

Harry Peak takes a polygraph test and the examiner concludes that Harry lied in response to every incriminating question.

Investigators arrest Harry Peak on a probable-cause warrant after multiple staff members identify him in a photo lineup.

The assistant district attorney declines to charge Harry Peak with arson, citing insufficient physical evidence.

Harry Peak files a multimillion-dollar lawsuit against the city of Los Angeles, and the city countersues him for the full cost of the fire.

Harry Peak appears in his attorney's office visibly ill with AIDS, and the city settles his lawsuit out of court for $35,000.

Central Library reopens its new Tom Bradley Wing to the public and over 10,000 people line up to sign up for library cards.

The Library Book centers on the 1986 fire that devastated the Los Angeles Central Library and the investigation that followed. After the blaze destroys or damages nearly 2 million books, hundreds of volunteers mobilize to rescue what remains while investigators pursue a blond young man spotted near the flames. That man, Harry Peak, becomes the focus of a years-long investigation involving a polygraph test, a public arrest, and competing civil lawsuits. Although the district attorney ultimately declines to charge Peak with arson, the case remains open as both sides sue each other for millions. Peak settles for a fraction of what he sought shortly before dying of AIDS, leaving the mystery of the fire permanently unsolved. Through it all, the library is rebuilt and expanded, reopening as a larger institution capable of serving an even more diverse Los Angeles.

The fire, the suspect, and the library's rebirth.

Orlean's son receives a school assignment and chooses to interview a librarian, prompting Orlean to accompany him and rediscover the library.

Orlean accompanies city librarian John Szabo on a full day of visits to neglected and thriving library branches across Los Angeles.

Los Angeles opens its first public library as a members-only reading room inside a social club, barring women and children entirely.

Mary Foy, an 18-year-old woman, is appointed head librarian of the Los Angeles library, the first female to hold such a position in the country.

Tessa Kelso modernizes the library and raises its cardholders to 20,000, but is eventually forced out after controversy with the board.

Charles Lummis walks cross-country from Ohio to Los Angeles, writing dispatches along the way and arriving as a celebrated journalist.

New York architect Bertram Goodhue is hired to design a new Central Library building that he conceptualized as something readable like a book.

Bertram Goodhue dies of a massive heart attack before the Central Library building he designed is completed.

The newly constructed Central Library, featuring a grand rotunda and zodiac chandelier, opens its doors to the public.

Althea Warren leads the Los Angeles Public Library through the Great Depression and adapts its services for World War II on a bare-bones budget.

A celebrity-studded telethon hosted in a Pentecostal church raises over $2 million for the Save the Books campaign to replace lost volumes.

The city sells Central Library's air rights to a real estate developer for $28.2 million, providing funds for a desperately needed new wing.

Construction crews begin restoring the Goodhue Building and break ground on the new library wing designed by architect Norman Pfeiffer.

Orlean visits the OverDrive headquarters in Cleveland and watches a screen showing real-time e-book lending from libraries all over the world.

Orlean's mother dies while Orlean is still writing The Library Book, deepening the personal stakes of the project.

Los Angeles's public library began as an exclusive, fee-charging reading room in a social club and gradually evolved into one of the most vital civic institutions in the country. A succession of pioneering librarians—including the nation's first female head librarian and the eccentric adventurer Charles Lummis—shaped its early character, while architect Bertram Goodhue gave the library its iconic building before dying just before its completion. Althea Warren steered the institution through the Depression and World War II on an austere budget, and the library continued expanding its reach even as its aging building fell into disrepair. After the 1986 fire, a celebrity telethon, the controversial sale of air rights, and a years-long construction campaign transformed the library into a larger and more capable institution. Orlean weaves her own story through this history, and by the book's end, writing about the library has become her way of holding onto memories of her mother, who died while the book was being written.

The library's history, from pioneer reading room to the digital age.

Wyman Jones hears news of the Central Library fire on his car radio and immediately rushes downtown to the scene.

Orlean climbs a hill and sets fire to a copy of Fahrenheit 451, watching the paperback disappear in flames within seconds.

Walking through the Digitization Department, Orlean realizes she must write this book to preserve memories she shared with her mother at libraries.

Caliph Omar orders the Library of Alexandria burned, and the great library is incinerated over six months, ending its existence permanently.

Ray Bradbury resumes his abandoned story about a book-burning society after hearing Senator McCarthy's inflammatory anti-Communist speech, completing Fahrenheit 451.

Arson investigator John Leonard Orr is convicted of arson and murder after investigators discover his fingerprint at a crime scene.

On the morning of the Central Library fire, multiple staff members independently report seeing a strange blond man in restricted staff areas.

Harry Peak calls his former boyfriend Hioteles on the day of the fire and tells a story about being rescued from the building by a handsome fireman.

That same night, Harry Peak tells friends in Santa Fe Springs that he personally started the Central Library fire.

Harry's friend Dennis Vines tests him by asking detailed questions about the library building; Harry cannot answer and Vines dismisses the story as fabrication.

Six out of eight library staff members pick Harry Peak's driver's license photo from a police photo lineup.

Harry Peak reverses all previous statements and tells investigators he was never at Central Library on the day of the fire.

After two years frozen, the recovered library books are thawed and sorted, with only 20 percent found fit for immediate shelving.

Fire expert Paul Bieber concludes that the Central Library fire's true point of origin cannot be reliably determined and that Harry Peak was likely the wrong suspect.

Orlean ultimately accepts that who or what started the Central Library fire will never be definitively known.

Many of the book's most revealing moments lie not in the fire itself but in the discoveries made in its wake. Orlean burns a book herself to understand the experience, and returns to writing after reconnecting with the library through grief over her mother's decline. Chapters on historical book burnings—from Alexandria to Nazi Germany—frame the Central Library fire within a long tradition of destroyed knowledge, while the story of arsonist-investigator John Leonard Orr shows how fire can serve as a twisted bid for fame. The investigation into Harry Peak unfolds through contradictions: multiple witnesses identify him, yet his friend easily exposes his boasting as fantasy, and his accounts of the day change constantly. Forensic expert Paul Bieber ultimately suggests there may never have been an identifiable arsonist, and Orlean closes the book accepting that the full truth about what happened that April morning will never be known.