“From me?” I echoed, yet next instant recollecting that I had given my name as Kirk.

“Yes, you telegraphed to him several days ago to meet you at the Caledonian Hotel in Glasgow. You are Mr Kirk, are you not?”

“Ah, of course, I recollect,” I laughed. “Do you think he’s gone to Glasgow?” I asked, as the sudden thought occurred to me.

“Well, sir,” replied the woman, “as you are such an intimate friend of Mr Martin’s, I think I ought to tell you that, before leaving to-night, he asked me in confidence to repeat any telegram that might come for him to the Caledonian in Glasgow, but asking me at the same time to give no information to anyone who might call and make inquiries as to his whereabouts.”

“Then he’s gone to Glasgow to-night!” I exclaimed, with sudden enthusiasm. “If I follow at once, I may find him!”

“I certainly think so, sir,” was the woman’s response, whereupon I made a hurried adieu, and, rejoining the German, into whose palm I slipped a sovereign, was quickly back at the hotel.

I left Princes Street Station at ten minutes to ten that night by the express due in Glasgow at eleven. That hour’s journey was full of excitement, for I was now upon the heels of the false Professor, whose whereabouts and assumed name Kirk knew, and with whom he had made an appointment.

Was this man, known as Martin, about to meet Kirk?

I laughed within myself when I reflected upon the awkward surprise which my presence there would give them. What the lodging-house keeper had told me proved conclusively that Kershaw Kirk had conspired to cause the death of poor Greer, and that the story he had told me was untrue.

Yet, again, there arose in my mind the problem why, if he were the assassin, or an accomplice of the assassin, should he introduce me into that house of death—myself a comparative stranger! Alone I sat in the corner of the railway carriage, thinking it all over, and trying, as I had so continuously tried, to discern light in the darkness.