"Best" is a relative term, and even here it comes with caveats, namely that the first two-fifths or so of the chapter are a bit of a wash. There's a section in which Eddie Willers, one of the rare characters who's neither a superman or social parasite but merely an unremarkable competent, speaks in a baldly expositional monologue to a low-ranking Taggart Transcontinental worker. Then there's a scene with Hank Rearden confronting and protecting Ragnar Danneskjöld, reverse-Robin Hood pirate who robs navy ships freighted with foreign aid.
(One could devote a whole post to rebutting Rand's position that Robin Hood "is remembered, not as a chamption of property, but as a champion of need, not as a defender of the robbed, but as a provider of the poor," but really, one need only point this out as another instance of Ayn Rand missing the bleeding point. That Robin Hood is a symbol of retributive justice, and not as a hookup for easy money, is something you either get or you don't.)
Anyway, the rest of the chapter is actually legitimately exciting. It concerns Washington bureaucrat Kip Chalmers, en route to San Francisco aboard the Taggart rail to give a speech the next day. The train breaks down because the government's regulations have reached such a fever pitch of incredible lunacy--with a Unification Board charged with making sure profits and payrolls across the board are frozen indefinitely (except for insider graft, naturally)--that the best workers have all walked away to save their dignity and have been replaced with less-than-capable scabs. Chalmers will not be delayed, however, so he demands that he be provided with a car that will get him to San Francisco on time. The problem, as the harried dispatcher tries to make clear to everyone, is that their train has to pass through an eight-mile tunnel that's only ventilated for a diesel engine. Because Taggart Transcontinental has so thoroughly gone to seed, the only engine available is an old coal-powered Comet, which will suffocate everyone onboard if they try to ride it through the tunnel. Everyone, from Colorado Division Superintendent Dave Mitchum to feeble CEO James Taggart to Dagny Taggart's replacement (she quit in protest of the Unifaction laws) Clifton Locey to all the various division leaders, is terrified of angering an all-powerful government hack, and so the responsibility for sending a train of passengers to their deaths is passed around like a hot potato before it is finally dropped in the lap of a nameless night dispatcher.
The episode culminates in a typically overlong (two-pages!) screed that details with increasing shrillness the background of various passengers, and why each one deserved his or her fate: (for context, the fire mentioned is Wyatt's Torch, an ever-burning flame in the mountains of Colorado left behind when industrialist Ellis Wyatt set fire to his oil fields in response to their nationalization.)
The scene doesn't have the prurient thrill of disembowelment and severed heads, but its sense of righteousness carries a nice charge. That final sentence in particular has a pungent, hoist-by-their-own-petard quality. And while by any realistic standard the absoluteness of the company's managerial impotence and criminal irresponsibility is ludicrous, on its own terms it's deliriously engaging. I know how wrong it is to say all this, but bear in mind that my favorite genre of literature is Elizabethan revenge tragedy, in which brutal crimes are answered tit-for-tat with perversely inventive retribution (would that everyone would read The Revenger's Tragedy, in which a lecherous poisoner is tricked into kissing the poison-painted lips of the skull of his victim!). After 500 pages of plodding plot and abstraction, it's nice to see some actual action; it should go without saying that, by so strenuously arguing the inherent justice of suffocating three hundred train passengers, the scene is morally several degrees worse than a merely tawdry Final Destination flick. To continue the tortured horror movie metaphor, it's about on the same level as Saw, which combines its sadism with long-winded moralizing.
As the tunnel came closer, they saw, at the edge of the sky far to the south, in a void of space and rock, a spot of living fire twisting in the wind. They did not know what it was and did not care to learn.
It is said that catastrophes are a matter of pure chance, and there were those who would have said that the passengers of the Comet were not guilty or responsible for the thing that happened to them.
The man in Bedroom A, Car No. 1, was a professor of sociology who taught that individual ability is of no consequence, that individual effort is futile, that an individual conscience is a useless luxury, that there is no individual mind or character or achievement, that everything is achieved collectively, and that it's masses that count, not men...
...The man in Roomette 3, Car No. 11, was a sniveling little neurotic who wrote cheap little plays into which, as a social message, he inserted cowardly little obscenities to the effect that all businessmen were scoundrels.
The woman in Roomette 9, Car No. 12, was a housewife who believed that she had the right to elect politicians, of whom she knew nothing, to control giant industries, of which she had no knowledge.
The man in Bedroom F, Car No.13, was a lawyer who had said, 'Me? I'll find a way to get along under any political system.'
The man in Bedroom A, Car No.14, was a professor of philosophy who taught that there is no mind - how do you know that the tunnel is dangerous? - no reality - how can you prove that the tunnel exists? - no logic - why do you claim that trains cannot move without motive power? - no principles - why should you be bound by the laws of cause and effect? - no rights - why shouldn't you attach men to their jobs by force? - no morality - what's moral about running a railroad? - no absolutes - what difference does it make to you whether you live or die anyway?. He taught that we know nothing - why oppose the orders of your superiors? - that we can never be certain of anything - how do you know you're right? - that we must act on the expediency of the moment - you don't want to risk your job do you?
The man in Drawing Room B, Car No.15, was an heir who had inherited his fortune, and who had kept repeating, 'Why should Rearden be the only one permitted to manufacture Rearden Metal?'
The man in Bedroom A, Car no. 16, was a humanitarian who had said, 'The men of ability? I do not care what or if they are made to suffer. They must be penalized in order to support the incompetent. Frankly, I do not care whether this is just or not. I take pride in not caring to grant any justice to the able, where mercy to the needy is concerned.'
These passengers were awake; there was not a man aboard the train who did not share one or more of their ideas. As the train went into the tunnel, the flame of Wyatt's Torch was the last thing they saw on earth.
That the philosophical equivalent of the guy from The Princess Bride sawing off his leg for the benefit of a clown puppet is the best part of Atlas Shrugged is not incidental. Writing, from the structure of plot down to word choice, is a window into the workings of an author's mind, and the Tunnel Disaster episode, with its unvarnished hatred, meticulous construction, and complete earnestness, provides a morbidly fascinating look into Ayn Rand, whose adolescent lionization of criminality as individualism had by now blossomed into outright misanthropy. Greater and more scrupulous authors and artists have explored ugly sides of humanity, but on some level there's always been a literary sheen applied, an artistry to give the depiction maximum impact. Rand lacked the skill for such tact but makes up for it with a conviction that even the best writer couldn't fake.
To quote another horror movie, a great one, and a character that also had no regard for human feelings, "Its structural perfection is matched only by its hostility....I admire its purity."