She made her decision. “If there has been fraud, and it is to do with the purchase of land, then that would be morally very wrong,” she said. “But if it concerns the actual building of the track, the cutting through hills, which is sometimes necessary, or the building of bridges and viaducts, and something is done which is not right, a matter of design or materials, do you not see, Mr. Monk, that the consequences could be far more serious . . . even terrible?”

A memory stirred in him so briefly he was not even sure if he imagined it, like a darkness at the edge of the mind. “What sort of consequence are you thinking of, Miss Harcus?”

She let her breath out in a sigh, then gulped. “The worst I can imagine, Mr. Monk, would be if a train were to come off the rails and crash. It could kill dozens of people . . . even hundreds . . .” She stopped. The idea of it was too dreadful to allow her to continue.

Train crash. The words moved something inside Monk like a bright, vicious dagger in his mind. He had no idea why. Certainly a train crash was a fearful thing, but was it any worse than loss at sea, or any other of a dozen disasters, natural or man-made?

“You understand?” Her voice came to him as if from far away.

“Yes!” he said sharply. “Of course I do.” He forced his attention back to the woman in front of him, and her problem. “You are afraid that some fraud in the construction of the railway, whether in the land used or the materials, may cause an accident in which many people could lose their lives. You think it possible Mr. Dalgarno may share the blame for this, even though you believe it extremely unlikely that he would be morally guilty. You would like me to find out the truth of the matter before any of this happens, and thereby prevent it.”

“I am sorry,” she said softly, but she did not lower her gaze. “I should not have questioned your understanding. That is exactly what I would like. Please . . . before you say anything else, look at the papers I have with me. I dare not leave them in case they are missed, but I believe they matter.” She reached for the bag at her feet and picked it up. She opened it and took out fifteen or twenty sheets of paper and leaned across, offering them to him.

He accepted them almost automatically. The first one was folded over, and he opened it. It was a survey map of a large area of countryside, most of it with many hills and valleys, and a line of railway track marked clearly through it. It took him a moment or two to recognize the names. It was in Derbyshire, on a line running roughly between London and Liverpool.

“This is the new line Mr. Dalgarno’s company is building?” he asked.