Lew understood that this business would not end with him walking out the door tonight and over to the El and on to some next assignment.
* * * * * * * * * *
I'm reading this sentence in two ways. First, once Lew walks out of this meeting to go about his other business, nothing will have changed. The people in the meeting still need to fight for their rights. They will continue to strike and to bomb factories and to make as much of a ruckus as they can so that their plight can no longer be ignored by the dumb, content masses. Lew couldn't stop it if he wanted to.
But the other way to read this—the more important way, I suppose—is that Lew can never go back to the life where he could say he didn't know or care about these kinds of issues. They have broken his heart with their music and their need, with their humanness and Americanness, and it is "unmendable." This business is now his business and he can't ignore it anymore. He'll leave the meeting and he'll go back to White City Investigations and he'll do his assignments. But he can't go back to simply thinking that his assignments do no harm. He'll no longer be able to simply follow orders. He once lived a life where he was able to keep himself from caring. But that life is no more. He can't not care now. He's seen the way things are and he, unlike many other Americans, cannot pretend it's different so that he doesn't have to pay the price of caring.
This experience Lew just had reminds me of Franz Pökler's realization in Gravity's Rainbow about how he allowed himself to not see or care about the concentration camps in Germany:
"Pökler helped with his own blindness. He knew about Nordhausen, and the Dora camp: he could see—the starved bodies, the eyes of the foreign prisoners being marched to work at four in the morning in the freezing cold and darkness, the shuffling thousands in their striped uniforms. He had known too, all along, that Ilse was living in a re-education camp. But it wasn't till August, when the furlough arrived as usual in its blank kraft envelope, and Pökler rode northward through the gray kilometers of a Germany he no longer recognized, bombed and burned, the wartime villages and rainy purple heath, and found her at last waiting in the hotel lobby at Zwölfkinder with the same darkness in her eyes (how had he missed it till now? such swimming orbits of pain) that he could finally put the two data together. For months, while her father across the wire or walls did his dutiful hackwork, she had been prisoner only a few meters away from him, beaten, perhaps violated. . . . If he must curse Weissmann, then he must also curse himself. Weissmann's cruelty was no less resourceful than Pökler's own engineering skill, the gift of Daedalus that allowed him to put as much labyrinth as required between himself and the inconveniences of caring. They had sold him convenience, so much of it, all on credit, and now They were collecting."
"The inconvenience of caring." That's what Nate and his coworkers and his clients are all selling. But Lew, having experienced the songs and the meeting and Moss Gatlin's words, has now, and forever after, been inconvenienced.