Fahrenheit 451 is set in an unspecified city (likely in the American Midwest) at an unspecified time in the future.[note 1] after the year 1960.[note 2]
The novel is divided into three parts: "The Hearth and the Salamander", "The Sieve and the Sand", and "Burning Bright".
"The Hearth and the Salamander"
Guy Montag is a "fireman" employed to burn the possessions of those who read outlawed books. He is married and has no children. One fall night while returning from work, he meets his new neighbor, a teenage girl named Clarisse McClellan, whose free-thinking ideals and liberating spirit cause him to question his life and his own perceived happiness. Montag returns home to find that his wife Mildred has overdosed on sleeping pills, and he calls for medical attention. Two uncaring EMTs come over to pump Mildred's stomach, drain her poisoned blood, and fill her with new blood. After the EMTs leave to rescue another overdose victim, Montag watches over Mildred, watching the new blood fill her pallid cheeks. Montag then goes outside, overhearing Clarisse and her family talk about the way life is in this hedonistic, illiterate society. Montag's mind is bombarded with Clarisse's subversive thoughts and the memory of his wife's near-death. The next day, Montag finds Mildred in the kitchen, with no memory of what happened and talking incessantly about being hungry from an alleged hangover she has from a party she thought she attended last night. Over the next few days, Clarisse faithfully meets Montag as he walks home. She tells him about how her simple pleasures and interests make her an outcast among her peers and how she's forced to go to therapy for her behavior and thoughts. Montag looks forward to these meetings, and just as he begins to expect them, Clarisse goes absent. He senses something is wrong.
In the following days, while at work with the other firemen ransacking the book-filled house of an old woman before the inevitable burning, Montag steals a book before any of his coworkers notice. The woman refuses to leave her house and her books, choosing instead to light a match and burn herself alive. Montag returns home jarred by the woman's suicide. While getting ready for bed, he hides the stolen book under his pillow. Still shaken by the night's events, he attempts to make conversation with Mildred, starting by asking her when they first met and where. Mildred goes to answer, but immediately forgets. As she laughs off her ignorance and heads for the bathroom to take more sleeping pills, Montag realizes just how much Mildred's sleeping pill addiction, love of vapid, interactive entertainment, and fast, reckless driving has ruined her mind and their marriage. Later, as Mildred is sleeping, Montag wakes her up and asks her if she has seen or heard anything about Clarisse McClellan. Mildred initially brushes off the question until she finally reveals what happened: Clarisse's family moved away after Clarisse got hit by a speeding car and died four days ago. Dismayed by her failure to mention this earlier, Montag uneasily tries to fall asleep. Outside he suspects the presence of "The Hound", an eight-legged robotic dog-like creature that resides in the firehouse and aids the firemen.
Montag awakens ill the next morning, with Mildred nagging him to get up and go to work. As Mildred tries to care for her husband (but finds herself more involved in the parlor wall entertainment in the next room), Montag suggests that maybe he should take a break from being a fireman after what happened last night. Mildred panics over the thought of losing the house and her parlor wall family and angrily blames the old woman who killed herself over her books for Montag's change of heart over his job. Captain Beatty, Montag's fire chief, personally visits Montag to see how he is doing. Sensing Montag's concerns, Beatty recounts how books lost their value and where the firemen fit in: over the course of several decades, people embraced new media (in this case, film and television), sports, and a quickening pace of life. Books were ruthlessly abridged or degraded to accommodate a short attention span while minority groups protested over the controversial, outdated content perceived to be found in literature (yet comic books, trade papers, and sex magazines were allowed to stay, as those fed into the population's want for mindless entertainment). The government took advantage of this by turning the firemen into officers of people's peace of mind. After an awkward encounter between Millie and Montag over the book hidden under Montag's pillow, Beatty is suspicious that Montag may have a book. Beatty casually adds a passing threat as he leaves, telling Montag that if a fireman had a book, he would be asked to burn it within the next 24 hours. If not, the other firemen would come and burn his house down for him. Despite the subtlety of the statement, the encounter leaves Montag shaken. He then decides to take action once and for all.
After Beatty has left, Montag reveals to Mildred that, over the last year, he has accumulated a stash of books that he has kept hidden in their air-conditioning duct. In a panic, Mildred grabs a book and rushes to throw it in their kitchen incinerator. Montag subdues her and tells her that the two of them are going to read the books to see if they have value. If they do not, he promises the books will be burned, and all will return to normal.
"The Sieve and the Sand"
When a sniffing occurs at their front door, Montag recognizes it as The Hound. Montag and Mildred discuss the stolen books, and Mildred refuses to go along with it, questioning why she or anyone else should care about books. Montag goes on a rant about Mildred's suicide attempt, Clarisse's disappearance and death, the old woman who burned herself, and the constant din of bombers flying overhead and the imminent threat of war that goes ignored by the masses. He then states that maybe the books of the past have messages that can save society from its own destruction. The conversation is interrupted by a call from Mildred's friend, Mrs. Bowles, and they set up a date to watch the "parlor walls" (large televisions lining the walls of her living room) that night at Mildred's house.
Montag, concedes that Mildred is a lost cause and he will need help to understand the books. Montag remembers an old man named Faber he once met in a park a year ago, an English professor before books were banned. He telephones Faber with questions about books, and Faber soon hangs up on him. Montag makes a subway trip to Faber's home along with a rare copy of the Bible, the book he stole at the woman's house. He tries to read it on the way, but gets distracted by a radio jingle advert and nearly goes insane. At Faber's house, Montag forces the scared and reluctant Faber into helping him by methodically ripping pages from the Bible. Faber concedes and gives Montag a homemade ear-piece communicator so he can offer constant guidance.
At home, Mildred's friends, Mrs. Bowles and Mrs. Phelps, arrive to watch the "parlor walls". Not interested in this insipid entertainment, Montag turns off the walls and tries to engage the women in meaningful conversation, only for them to reveal just how indifferent, ignorant, and callous they are about the upcoming war, the thought of losing loved ones to death, their unruly children, and who they voted for in the last election. Enraged by their idiocy, Montag leaves momentarily and returns with a book of poetry. This confuses the women and alarms Faber, who is listening remotely. Mildred tries to dismiss Montag's actions as a tradition fireman do once a year: they find a book from the past and read it as a way to make fun of how silly the past is. Montag proceeds to recite the poem Dover Beach, causing Mrs. Phelps to cry. At the behest of Faber in the ear-piece, Montag burns the book. Mildred's friends leave in disgust, while Mildred takes more sleeping pills.
In the aftermath of the parlor party, Montag hides his books in his backyard before returning to the firehouse late at night with just the stolen Bible. He finds Beatty playing cards with the other firemen. Montag hands Beatty a book to cover for the one he believes Beatty knows he stole the night before, which is unceremoniously tossed into the trash. Beatty tells Montag that he had a dream in which they fought endlessly by quoting books to each other. Thus Beatty reveals that, despite his disillusionment, he was once an enthusiastic reader. A fire alarm sounds, and Beatty picks up the address from the dispatcher system. They drive in the firetruck recklessly to the destination: Montag's house.
Beatty orders Montag to destroy his own house, telling him that his wife and her friends reported him after what happened the other night. Montag watches as Mildred walks out of the house, too traumatized about losing her parlor wall family to even acknowledge her husband's existence or the situation going on around her, and catches a taxi, never once looking back. Montag obeys the chief, destroying the home piece by piece with a flamethrower. As soon as he has incinerated the house, Beatty discovers Montag's ear-piece and plans to hunt down Faber. Montag threatens Beatty with the flamethrower and (after Beatty taunts him) burns his boss alive, and knocks his coworkers unconscious. As Montag escapes the scene, the firehouse's Mechanical Hound attacks him, managing to inject his leg with a tranquilizer. He destroys the Hound with the flamethrower and limps away. Before he escapes, however, he realizes that Beatty had wanted to die a long time ago and had purposely goaded Montag, as well as provided him with a weapon.
Montag runs through the city streets towards Faber's house. Faber urges him to make his way to the countryside and contact the exiled book-lovers who live there. He mentions he will be leaving on an early bus heading to St. Louis and that he and Montag can rendezvous there later. On Faber's television, they watch news reports of another Mechanical Hound being released, with news helicopters following it to create a public spectacle. After wiping his scent from around the house in hopes of thwarting the Hound, Montag leaves Faber's house. He escapes the manhunt by wading into a river and floating downstream. Montag leaves the river in the countryside, where he meets the exiled drifters, led by a man named Granger. Granger shows Montag the ongoing manhunt on a portable battery TV, and predicts that “Montag” will be caught within the next few minutes. As predicted, an innocent man is then caught and killed.
The drifters are all former intellectuals. They have each memorized books should the day come that society comes to an end, then rebuilds itself anew; this time, with the survivors learning to embrace the literature of the past. While learning the philosophy of the exiles, Montag and the group watch helplessly as bombers fly overhead and annihilate the city with nuclear weapons. While Faber would have left on the early bus, everyone else (including Mildred) was immediately killed. Montag and the group are injured and dirtied, but manage to survive the shock wave.
The following morning, Granger teaches Montag and the others about the legendary phoenix and its endless cycle of long life, death in flames, and rebirth. He adds that the phoenix must have some relationship to mankind, which constantly repeats its mistakes. Granger explains that man has something the phoenix does not: mankind can remember its mistakes and try never to repeat them. Granger then muses that a large factory of mirrors should be built, so that way people can take a long look at themselves and reflect on their lives. When the meal is over, the exiles return to the city to rebuild society.