"And so am I, and that's one comfort," continued Henderson. "That poor girl, Lucy Ray, although she was to be blamed for her conduct, is much to be pitied now; and as to poor Wynne himself, he protests his innocence through thick and thin. He was a wild fellow, but not the sort to take the life of a fellow-creature. I saw the doctor this afternoon while I was waiting for you at the inn, Mr. Bell, and also the police sergeant. They both say they do not know what Davidson died of. There was not the least sign of violence on the body." "Well, I am as puzzled as the rest of you," I said. "I have one or two theories in my mind, but none of them will quite fit the situation." The night was piercingly cold, and, although there was not a breath of wind, the keen and frosty air penetrated into the lonely signal-box. We spoke little, and both of us were doubtless absorbed by our own thoughts and speculations. As to Henderson, he looked distinctly uncomfortable, and I cannot say that my own feelings were too pleasant. Never had I been given a tougher problem to solve, and never had I been so utterly at my wits' end for a solution. Now and then the Inspector got up and went to the telegraph instrument, which intermittently clicked away in its box. As he did so he made some casual remark and then sat down again. After the 10.40 had gone through, there followed a period of silence which seemed almost oppressive. All at once the stillness was broken by the whirr of the electric bell, which sounded so sharply in our ears that we both started. Henderson rose. "That's the 11.45 coming," he said, and, going over to the three long levers, he pulled two of them down with a loud clang. The next moment, with a rush and a scream, the express tore down the cutting, the carriage lights streamed past in a rapid flash, the ground trembled, a few sparks from the engine whirled up into the darkness, and the train plunged into the tunnel. "And now," said Henderson, as he pushed back the levers, "not another train till daylight. My word, it is cold!" It was intensely so. I piled some more wood on the fire and, turning up the collar of my heavy ulster, sat down at one end of the bench and leant my back against the wall. Henderson did likewise; we were neither of us inclined to speak. As a rule, whenever I have any night work to do, I am never troubled with sleepiness, but on this occasion I felt unaccountably drowsy. I soon perceived that Henderson was in the same condition. "Are you sleepy?" I asked of him. "Dead with it, sir," was his answer; "but there's no fear, I won't drop off." I got up and went to the window of the box. I felt certain that if I sat still any longer I should be in a sound sleep. This would never do. Already it was becoming a matter of torture to keep my eyes open. I began to pace up and down; I opened the door of the box and went out on the little platform. "What's the matter, sir?" inquired Henderson, jumping up with a start.