"Your profession is not that of a detective?" he suggested, with a laugh. "No; I'm a motor engineer," I explained bluntly. "I know nothing, and care less, about detectives and their ways." Then I apologised for disturbing him at that hour and made my way back in the cab that had brought me to the centre of the city. I left New Street Station at two o'clock in the morning--cold, wet, and cheerless--and at half-past four was in the Midland Hotel at Sheffield, sleepy and fagged. The night-porter knew nothing of Sir Mark Edwards' address; therefore I had to wait until eight o'clock, when some more intelligent member of the hotel staff came on duty. Everyone of whom I inquired, however, seemed ignorant; hence I took a cab and drove to the great works of the firm--a huge, grimy place, with smoky chimneys and heaps of slag, an establishment employing several thousand hands, and one of the largest, if not the largest, in Hallamshire. Here I was informed that Sir Mark resided thirty miles distant, at Alverton Hall, close to the edge of Bulwell Common, famed for its golf links. Therefore at ten o'clock I took train there, and, finding a fly at the station, drove direct to the Hall to face and denounce the man who was an accomplice of assassins, if not the assassin himself, and a bold, defiant impostor. The fly, after traversing a country road for a mile or so, suddenly entered the lodge-gates and proceeded up a splendid avenue of high bare elms, until we drew up at the entrance to a fine old Elizabethan mansion, the door of which was thrown open by a liveried man-servant. I held my breath for a second. My chase had been a long and stern one. Then I inquired for the honoured and distinguished guest--who I had already ascertained at the works in Sheffield was supposed to be staying there--and was ushered with great ceremony into the wide, old-fashioned hall. At last the impostor was near his unmasking. At last I would be able to prove to the world who killed Professor Greer! CHAPTER TWENTY SEVEN. SEVERAL REVELATIONS. Alverton Hall, a noble old mansion, had been purchased by the Sheffield steel magnate Sir Mark Edwards some ten years before. In addition, I heard that he owned a beautiful place in Glamorganshire and rented a great deer-forest in Scotland. He was one of England's manufacturing princes, whose generosity to charitable institutes and to the city of Sheffield was well known, and whose daughter had, only a year ago, married into the peerage. A short, bluff, bald-headed old fellow, he spoke quickly, almost snappishly, when I was ushered into his presence in a small, cosily-furnished room that looked out upon a fine old-world terrace, with a Jacobean garden beyond. "It is true that I'm expecting Professor Greer on a visit here," he said, with a broad Hallamshire accent, in reply to my question. "Who, may I ask, are you?"