Rearden sells his ore mines to Paul Larkin and his coal mines to Ken Danagger, a hard-bitten Pennsylvania coal producer who started his career as a miner. Rearden's calls to Wesley Mouch in Washington go unanswered, and he then receives a letter announcing Mouch's resignation. Two weeks later, Rearden reads in the newspapers that Mouch has been appointed Assistant Coordinator of the Bureau of Economic Planning and National Resources.
Meanwhile, despite concerted public and government opposition, Dagny completes construction of the John Galt Line on time. She asks for volunteers among Taggart employees to run the first train, and she receives offers from virtually every engineer on the system. The volunteers draw lots for the run and, at a press conference, Dagny and Rearden announce that they'll ride in the cab of the engine on the new line's first train run. Although many people predict that the rail will crack and the bridge will collapse, the first run of the John Galt Line is a resounding success. Afterward, Dagny and Rearden have dinner privately with Ellis Wyatt at his home. When dinner is over and it's time to retire, Dagny and Rearden make love for the first time.
Rearden doesn't realize that Paul Larkin is part of the corrupt deal brokered by James Taggart and Orren Boyle that is designed to strip him of his mines and extinguish the Phoenix-Durango Railroad. Rearden sells his mines to Larkin because he thinks he's trustworthy, but Larkin is another corrupt businessman who prospers only in a socialist system. However, Rearden does have a trustworthy ally in Ken Danagger. Danagger is a self-made man. He started at the bottom of the coal business as a miner and rose to the top by means of his own ability and indomitable work ethic, like Rearden. As men who make their own way in the world, relying neither on handouts nor government coercion, Danagger and Rearden understand each other.
The actions of Wesley Mouch are, of course, those of a corrupt politician. His betrayal of Rearden and his affiliation with the James Taggart camp are examples of a socialist economy at work. When the government is granted the legal power to control the economy, it has the power to dispense economic favors. A government with such power attracts power-seeking politicians as well as corrupt, incompetent businesspeople who flourish only behind the barrel of the government's gun. Mouch, for example, is an inconsequential nobody. In a capitalist system, where he would have to compete fairly on an open market, he would not succeed. But in a socialist system, where he can manipulate the coercive power of the state, Mouch can rise to a position of influence in the government.
The events surrounding the completion and running of the first train on the John Galt Line are significant for their portrayal of two contrasting cognitive camps. James Taggart and others are concerned because public opinion is firmly set against Rearden Metal and Dagny's railroad. In fact, Jim tries to buy steel rail from the Phoenix-Durango line, which is closing. Although such a purchase would be costly, Jim says that the goodwill generated by caving in to public demand would more than compensate the railroad's expense. On the other hand, Dagny and Rearden are utterly unconcerned that public opinion is against them, because they know that they have a vastly more powerful ally — the facts. Rearden Metal is superb, and the facts will speak for themselves.
Through the characters of James Taggart and other parasitic people, Ayn Rand dramatizes the theory that truth is defined by social opinion — that "fifty million Frenchmen can't be wrong," that cognition is a democratic process, and that truth is determined by vote. Through the characters of Dagny and Rearden, Rand exemplifies the theory that truth results when an idea corresponds to facts — that a Rearden Metal bridge will stand or fall based on its molecular properties, not on public opinion. Dagny and Rearden are rational and scientific, relying on facts. James Taggart looks to public opinion for the truth, much like a poll-dependent politician. In a way, the fact that Dagny and Rearden pay no attention to mistaken public opinion is a sign of respect for their fellow man; they are confident that most people are rational enough to accept the truth when they see it for themselves. Dagny and Rearden believe that when the John Galt Line runs successfully, the public will be convinced of the fact that Rearden Metal is superior to any other metal. They believe that the public will ignore the corrupt information they've been fed by government agencies.
The relationship growing between Rearden and Dagny is based on the profound values that they share. Their mutual love of industrialization, technological advance, and man's prosperity on earth goes beyond the immediate commitment that they both have to the Rearden Metal track and the John Galt Line. Likewise, the cognitive method described above — the commitment to facts and the rejection of social opinions — is their deepest connection. Given the principles that they share and the battle that they fight to defend those principles, it is inevitable that Dagny and Rearden fall in love.