Carborough curled his lip. “Stupid to get caught in something as trivial as that,” he said, shaking his head. “Never understood it myself. He was brilliant. One of the best merchant bankers in the city, if not the best. Then he goes and does a foolish thing like changing the grid reference on a survey so they move the course of the track onto his own land, and he makes . . . what?” He shrugged. “A thousand pounds at most. Hardly as if he needed it. And at the time he did it, he’d have expected to get an interest in whatever the company made on the new brakes. He found the money to develop them.”

“What new brakes?” Monk said quickly.

Carborough opened his eyes wide.

“Oh . . . they invented their own system of braking for carriages and goods wagons. Quite a bit cheaper than the standard ones used now. Would have cleaned up a fortune. Don’t know what happened there. They never followed through with it.”

“Why not?” he asked. The same flicker of memory woke in Monk and died in the same instant.

“Don’t know that, Mr. Monk,” Carborough replied. “After Dundas’s trial everything seemed to stop for a while. Then he died, you know?” He put the pencil down next to his pad, making it perfectly level. “In prison, poor devil. Maybe the shock of it all was too much. Anyway, after that they concentrated on new lines. Seemed to forget all about brakes. Built their own wagons and so on. Did pretty well out of it. As I said, moved down to London.”

Monk asked him more questions, but Carborough knew nothing about Dundas personally and had not heard Monk’s name before that he recalled.

Neither was there any sign of the money that Dundas must have received for his house. It had vanished as completely as if the treasury notes it was paid in had been burned.

The next step was to pursue the Reverend William Colman, who had given such telling evidence against Dundas. It might be an unpleasant encounter, since Colman would certainly remember Monk from the trial. He would be the first person Monk had spoken to who had known him from that time. Dundas and his wife were both dead, and so was Nolan Baltimore. Monk would be coming face-to-face with the reality of who he had been, and finally there would be no escape from whatever Colman remembered of him.

Had he hated the man then, for his evidence? Had he been offensive to him, tried to discredit him? Had Colman even believed him equally guilty with Dundas, but simply been unable to prove it?