King Coal by Upton Sinclair

It had been a crude and stupid plot, yet Hal realised that it was adapted to the intelligence of the men for whom it was intended. But for the accident that he had stayed awake, they would have found the money on him, and next morning the whole camp would have heard that he had sold out. Of course his immediate friends, the members of the committee, would not have believed it; but the mass of the workers would have believed it, and so the purpose of Tom Olson's visit to North Valley would have been balked. Throughout the experiences which were to come to him, Hal retained his vivid impression of that adventure; it served to him as a symbol of many things. Just as the bosses had tried to bedevil him, to destroy his influence with his followers, so later on he saw them trying to bedevil the labour-movement, to confuse the intelligence of the whole country.

Now Hal was in jail. He went to the window and tried the bars -- but found that they had been made for such trials. Then he groped his way about in the darkness, examining his prison, which proved to be a steel cage built inside the walls of an ordinary room. In one corner was a bench, and in another corner another bench, somewhat broader, with a mattress upon it. Hal had read a little about jails -- enough to cause him to avoid this mattress. He sat upon the bare bench, and began to think.