I staggered into my room and clutched at the bed-rail to support myself, for my legs threatened to collapse beneath me. How should I act? That we were victims of a cunning plot, that the deathful Si-Fan had at last wreaked its vengeance upon Nayland Smith I could not doubt. My brain reeled, and a weakness, mental and physical, threatened to conquer me completely. Indeed, I think I must have succumbed, sapped as my strength had been by the drug administered to me, if the sound of a creaking stair had not arrested my attention and by the menace which it conveyed afforded a new stimulus. Some one was creeping down from the landing above--coming to my room! The creatures of the Yellow doctor, having despatched Nayland Smith, were approaching stealthily, stair by stair, to deal with _me!_ From my grip I took out the Browning pistol. The Chinese doctor's servants should have a warm reception. I burned to avenge my friend, who I was persuaded, lay murdered in the room above. I partially closed the door and took up a post immediately behind it. Nearer came the stealthy footsteps--nearer.... Now the one who approached had turned the angle of the passage.... Within sight of my door he seemed to stop; a shaft of white light crept through the opening, across the floor and on to the wall beyond. A moment it remained so--then was gone. The room became plunged in darkness. Gripping the Browning with nervous fingers I waited, listening intently; but the silence remained unbroken. My gaze set upon the spot where the head of this midnight visitant might be expected to appear, I almost held my breath during the ensuing moments of frightful suspense. The door was opening; slowly--slowly--by almost imperceptible degrees. I held the pistol pointed rigidly before me and my gaze remained fixed intently on the dimly seen opening. I suppose I acted as ninety-nine men out of a hundred would have done in like case. Nothing appeared. Then a voice--a voice that seemed to come from somewhere under the floor snapped:-- "Good God! it's Petrie!" I dropped my gaze instantly ... and there, looking up at me from the floor at my feet, I vaguely discerned the outline of a human head! "Smith!" I whispered. Nayland Smith--for indeed it was none other--stood up and entered the room. "Thank God you are safe, old man," he said. "But in waiting for one who is stealthily entering a room, don't, as you love me, take it for granted that he will enter _upright_. I could have shot you from the floor with ease! But, mercifully, even in the darkness, I recognized your Arab slippers!" "Smith," I said, my heart beating wildly, "I thought you were drugged-- murdered. The port contained an opiate." "I guessed as much!" snapped Smith. "But despite the excellent tuition of Dr. Fu-Manchu, I am still childishly trustful; and the fact that I did not partake of the crusted '45 was not due to any suspicions which I entertained at that time." "But, Smith, I saw you drink some port."