As neighbors watch, Captain Beatty confronts Montag about his misconduct. He must have been influenced, Beatty says, by "that little idiot," Clarisse. Montag defends her, but Beatty dismisses him. As they argue, Mildred comes out the front door with a suitcase packed. She ignores Montag and wordlessly climbs into a waiting cab.

Through the earpiece, Faber asks Montag what's happening. When Montag tells him, Faber encourages him to run away. Before he can, Captain Beatty insists that Montag actively participate in the burning using one of the department's most destructive tools: a flamethrower. Montag burns it all: the bedroom, the books, the house, and, finally, the parlor walls. "When you're quite finished," Beatty tells him, "you're under arrest."

As the house burns, Montag asks Captain Beatty if Mildred is the one who turned him in to the authorities. She did, Beatty tells him, but one of her friends did first. Beatty then notices Montag's earpiece and hits him hard in the head. The earpiece falls out, and Beatty picks it up, promising Montag that he'll trace it back and find out who he's been talking to.

Montag, still holding the flamethrower, notices that he has subconsciously undone the safety. As the captain continues to taunt him, Montag hits the trigger one more time and shoots directly at Beatty. Beatty is instantly killed, and Montag shoots it again at the other two firemen and their mechanical hound.

As the authorities draw near, Montag collects a few hidden books from the house's garden. Beatty wanted to be burned, he realizes. Montag had been taunted into it. Hearing footsteps, he runs, realizing that he no longer has his direct connection to Faber. Finding a regular seashell in his pocket, he hears the breaking news alert: Guy Montag, a dangerous fugitive, is on the loose.

While Montag flees, the news breaks that war has been declared. Coming upon a gas station, Montag composes himself and, by walking slowly, manages to blend in and re-emerge looking like a normal customer. As he leaves, he's nearly hit by a car full of speeding teenagers, and he wonders if they might be the ones who hit Clarisse.

Montag disappears into the darkness and eventually stops by another fireman's house to hide his remaining books inside. Finding a phone booth nearby, he calls in the tip to the authorities before continuing on to Faber's house. He tells him what happened, and Faber reassures Montag that he only did "what he had to do." He asks Montag his plans, and Montag responds that he has to keep running.

Faber tells Montag that he should follow the old railroad lines—they might lead to some camps out in the woods where intellectuals and academics live in secrecy. "They say there's lots of old Harvard degrees on the tracks between here and Los Angeles," Faber tells him. "Most of them are wanted and hunted in the cities. They survive, I guess."

Faber takes out a small video receiver, and they check the news. The authorities are moving quickly, and they've brought in another mechanical hound from a neighboring department to track Montag's scent. Montag tells Faber to wash everything he's touched, and Faber gives him a suitcase of his old clothes to change into when he's far enough away for the mechanical hound to lose his scent.

Montag flees again, stopping to peer in at the news report on the parlor walls of a nearby house. He realizes they're very close to catching him and that he doesn't have much time left. Monitoring the chase on the seashell earpiece, he runs as fast as he can to the river on the edge of town. He throws his old clothes into the river and takes a bath, washing his scent off himself as best he can. Then he puts on Faber's clothes and allows himself to be swept downstream.

As Montag floats, he finally has time to consider his recent experiences without distraction. For the first time, he has the opportunity to reflect and contemplate without rushing. He thinks about his own life but also considers the world outside himself in a new, expansive way. He notices the moon and wonders about it for the first time. He wonders about the sun, and the passage of time, and heliocentricity.

As he hits shore, he notices something else unusual: the silence. He thinks, solemnly, about Mildred and how much she would hate it. He then notices the smell: hay in the air. He daydreams about a barn and what kind of life a person might be able to lead living in one. Montag steps out of the river and is overwhelmed by his sensory experience—the darkness, the cold, the earthy smells, the sounds.

Finding the railroad tracks at his feet, he begins to follow them. He's struck by a strange, inexplicable sense that Clarisse must once have walked the same tracks. After half an hour of walking, he sees a fire up ahead. It's a familiar sight, he realizes, but an unfamiliar use—this fire is used for warmth, not for destruction.

The men around the fire welcome Montag by name, and a man called Granger gives him a chemical solution that will change his body chemistry and throw the mechanical hound off his trail once and for all. He shows Montag the news, telling him that they've been expecting him. The authorities will never admit that they've lost track of him, Granger notes, and this proves to be true—together, they watch footage of "Montag" being captured and killed onscreen by the mechanical hound.

Granger introduces the others, all former academics and intellectuals, and asks Montag if he's brought anything with him. Montag tells Granger he had a book of Ecclesiastes, but it's only in his head now. Granger tells him that's perfect and that he must safeguard it—he is now a copy of Ecclesiastes, and if something happens to the other one, he may be the last. They all have committed books to memory, he tells Montag. By passing the stories down among themselves, they can safeguard them until it's safe to write them down again.

The men put out the fire, and Montag helps—his first ever extinguishing. As they move downstream and tell each other of their lives, an enormous bomb goes off over the city. Montag and the others are knocked down by the blast.

As they stir, the dust settles, and they see that the city has been entirely flattened. Granger tells Montag the story of the phoenix—a great mythical bird who dies in fire and is reborn from the ashes. In silence, the men forge ahead toward the city. Montag thinks of what he might say later, a passage from Ecclesiastes, but chooses to wait until the time is right: "If the men were silent, it was because there was everything to think about and much to remember."