Ayn Rand emphasizes here that industrial production is just as creative as writing a novel or composing a symphony. Industrial production is also fueled by love — love for the creation of material abundance and the positive, constructive act of making possible man's life on earth. Such love isn't to be relinquished lightly, which is why Francisco experienced such torment when he chose to leave and is also why Dagny can't yet join him.
Dagny and Rearden have learned that the collapse of the world's economy isn't caused by random factors or solely by the irrationality of the looters' code. The thinkers have systematically withdrawn their minds from the world, hastening the collapse of the looters' regime. Seemingly notorious figures like Francisco d'Anconia and Ragnar Dannejsköld are, in their own ways, fighting the evil that's currently in power. The tempo of the resistance quickens as each great mind walks away from the world. At this point, it begins to look as if the great minds have a chance to defeat the irrational forces in power. But if the thinkers succeed, what will victory cost Dagny's railroad and Rearden's mills?
