In an environment of worsening economic conditions, Dagny Taggart, vice president in charge of operations, works to repair Taggart Transcontinental’s crumbling Rio Norte Line to service Colorado, the last booming industrial area in the country. Her efforts are hampered by the fact that many of the country’s most talented entrepreneurs are retiring and disappearing. The railroad’s crisis worsens when the Mexican government nationalizes Taggart’s San Sebastian Line. The line had been built to service Francisco d’Anconia’s copper mills, but the mills turn out to be worthless. Francisco had been a successful industrialist, and Dagny’s lover, but has become a worthless playboy. To solve the railroad’s financial problems, Dagny’s brother Jim uses political influence to pass legislation that destroys Taggart’s only competition in Colorado. Dagny must fix the Rio Norte Line immediately and plans to use Rearden Metal, a new alloy created by Hank Rearden. When confronted about the San Sebastian mines, Francisco tells Dagny he is deliberately destroying d’Anconia Copper. Later he appears at Rearden’s anniversary party and, meeting him for the first time, urges Rearden to reject the freeloaders who live off of him.
The State Science Institute issues a denunciation of Rearden metal, and Taggart’s stock crashes. Dagny decides to start her own company to rebuild the line, and it is a huge success. Dagny and Rearden become lovers. Together they discover a motor in an abandoned factory that runs on static electricity, and they seek the inventor. The government passes new legislation that cripples industry in Colorado. Ellis Wyatt, an oil industrialist, suddenly disappears after setting fire to his wells. Dagny is forced to cut trains, and the situation worsens. Soon, more industrialists disappear. Dagny believes there is a destroyer at work, taking men away when they are most needed. Francisco visits Rearden and asks him why he remains in business under such repressive conditions. When a fire breaks out and they work together to put it out, Francisco understands Rearden’s love for his mills.
Rearden goes on trial for breaking one of the new laws, but refuses to participate in the proceedings, telling the judges they can coerce him by force but he won’t help them to convict him. Unwilling to be seen as thugs, they let him go. Economic dictator Wesley Mouch needs Rearden’s cooperation for a new set of socialist laws, and Jim needs economic favors that will keep his ailing railroad running after the collapse of Colorado. Jim appeals to Rearden’s wife Lillian, who wants to destroy her husband. She tells him Rearden and Dagny are having an affair, and he uses this information in a trade. The new set of laws, Directive 10-289, is irrational and repressive. It includes a ruling that requires all patents to be signed over to the government. Rearden is blackmailed into signing over his metal to protect Dagny’s reputation.
Dagny quits over the new directive and retreats to a mountain lodge. When she learns of a massive accident at the Taggart Tunnel, she returns to her job. She receives a letter from the scientist she had hired to help rebuild the motor, and fears he will be the next target of the destroyer. In an attempt to stop him from disappearing, she follows him in an airplane and crashes in the mountains. When she wakes up, she finds herself in a remote valley where all the retired industrialists are living. They are on strike, calling it a strike of the mind. There, she meets John Galt, who turns out to be both the destroyer and the man who built the motor. She falls in love with him, but she cannot give up her railroad, and she leaves the valley. When she returns to work, she finds that the government has nationalized the railroad industry. Government leaders want her to make a speech reassuring the public about the new laws. She refuses until Lillian comes to blackmail her. On the air, she proudly announces her affair with Rearden and reveals that he has been blackmailed. She warns the country about its repressive government.
With the economy on the verge of collapse, Francisco destroys the rest of his holdings and disappears. The politicians no longer even pretend to work for the public good. Their vast network of influence peddling creates worse chaos, as crops rot waiting for freight trains that are diverted for personal favors. In an attempt to gain control of Francisco’s mills, the government stages a riot at Rearden Steel. But the steelworkers organize and fight back, led by Francisco, who has been working undercover at the mills. Francisco saves Rearden’s life, then convinces him to join the strike.
Just as the head of state prepares to give a speech on the economic situation, John Galt takes over the airwaves and delivers a lengthy address to the country, laying out the terms of the strike he has organized. In desperation, the government seeks Galt to make him their economic dictator. Dagny inadvertently leads them to him, and they take him prisoner. But Galt refuses to help them, even after he is tortured. Finally, Dagny and the strikers rescue him in an armed confrontation with guards. They return to the valley, where Dagny finally joins the strike. Soon, the country’s collapse is complete and the strikers prepare to return.