I began to wonder again whether it was not probable that Northcote was a lunatic, or that he was playing some stupendous practical joke at my expense. I ran over in my mind the whole of our interview, from the moment when he had waylaid me. There was certainly no sign of madness about him, apart from his amazing proposals; and if the whole thing were a jest, well, it promised to be a pretty expensive one for its author. Besides that, I felt sure that the man was in danger of his life, or at all events believed himself to be so. There was no acting about the sudden flash with which his hand had travelled to his pocket in that second on the Embankment. Pulling out the paper which he had given me, I lit a wax match and began to study his plan of the house. It seemed simple enough. I only had to walk upstairs, and my bedroom was facing me on the other side of the landing, the windows apparently looking out into the Park. That knowledge, at all events, promised to be sufficient for the night. I could reserve anything in the nature of further exploration until the next morning. By this time we had reached Hyde Park corner, and, crossing the road, the driver turned to the right up Park Lane. Beyond knowing the number, I had not the remotest notion where Northcote lived, and I had something of a shock when we stopped quite suddenly outside an imposing-looking mansion only about a hundred yards above Apsley House. "Good Lord!" I muttered. "I hope there's no mistake." At all events, the number was on the gate-post right enough, and the driver seemed quite confident that he had reached his correct destination. So, pulling myself together, I stepped on to the pavement and handed the man half a crown. He touched his cap respectfully, and putting in his clutch, glided away slowly in the direction of Oxford Street. For perhaps thirty seconds I hesitated; then, mounting the broad stone steps, I thrust my latch-key into the door. It opened easily enough, and with a deep breath I stepped in over the threshold. I found myself in a large circular hall, surrounded by several stone pillars and lit by an electric chandelier. A plentiful supply of palm trees in pots, and some beautiful hanging baskets of hothouse flowers, lent the place an air of luxury and comfort, which was increased by the deep easy-chairs of red leather scattered about in various corners. So far, I had certainly no fault to find with my new home. I had just closed the front door, and was advancing across the thick, noiseless Turkey carpet, when there was a sound of discreet footsteps, and a man suddenly appeared from a curtained aperture at the back of the hall. He was a quiet, pleasant-looking fellow of about forty-five, with an alert, clean-shaven face, and hair just beginning to turn grey. His clothes were the conventional costume of an English butler. "This," I said to myself, "must be Milford." I took off my hat, so that the light fell full on my face.