The next moment we drew up at the inn where the Inspector was waiting, and soon afterwards were bowling along between the high banks of the country lanes to the tunnel. It was a cold, still afternoon; the air was wonderfully keen, for a sharp frost had held the countryside in its grip for the last two days. The sun was just tipping the hills to westward when the trap pulled up at the top of the cutting. We hastily alighted, and the Inspector and I bade Bainbridge good-bye. He said that he only wished that he could stay with us for the night, assured us that little sleep would visit him, and that he would be back at the cutting at an early hour on the following morning; then the noise of his horse's feet was heard fainter and fainter as he drove back over the frost-bound roads. The Inspector and I ran along the little path to the wicket-gate in the fence, stamping our feet on the hard ground to restore circulation after our cold drive. The next moment we were looking down upon the scene of the mysterious deaths, and a weird and lonely place it looked. The tunnel was at one end of the rock cutting, the sides of which ran sheer down to the line for over a hundred and fifty feet. Above the tunnel's mouth the hills rose one upon the other. A more dreary place it would have been difficult to imagine. From a little clump of pines a delicate film of blue smoke rose straight up on the still air. This came from the chimney of the signal-box.
As we started to descend the precipitous path the Inspector sang out a cheery "Hullo!" The man on duty in the box immediately answered. His voice echoed and reverberated down the cutting, and the next moment he appeared at the door of the box. He told us that he would be with us immediately; but we called back to him to stay where he was, and the next instant the Inspector and I entered the box.
"The first thing to do," said Henderson the Inspector, "is to send a message down the line to announce our arrival."
This he did, and in a few moments a crawling goods train came panting up the cutting. After signalling her through we descended the wooden flight of steps which led from the box down to the line and walked along the metals towards the tunnel till we stood on the spot where poor Davidson had been found dead that morning. I examined the ground and all around it most carefully. Everything tallied exactly with the description I had received. There could be no possible way of approaching the spot except by going along the line, as the rocky sides of the cutting were inaccessible.
"It is a most extraordinary thing, sir," said the signalman whom we had come to relieve. "Davidson had neither mark nor sign on him—there he lay stone dead and cold, and not a bruise nowhere; but Pritchard had an awful wound at the back of the head. They said he got it by climbing the rocks—here, you can see the marks for yourself, sir. But now, is it likely that Pritchard would try to climb rocks like these, so steep as they are?"
"Certainly not," I replied.
"Then how do you account for the wound, sir?" asked the man with an anxious face.
"I cannot tell you at present," I answered.
"And you and Inspector Henderson are going to spend the night in the signal-box?"
"Yes."