Room 4167, then, was on the fourth floor--the topmost floor of the structure. I must confess that the knowledge did not bring any renewed burst of courage! The top floor! Three black stair-pits would lie between me and the safety of escape. There would be no escape! No human being in the throes of fear could hope to discover that tortured outlet, could hope to grope his way through Stygian gloom down a triple ramp of black stairs. And even though he succeeded in reaching the lower corridors, there was still a blind alley-way, sealed at the outer end by a high grating of iron bars.... * * * * * Escape! The mockery of it caused me to stop suddenly in my ascent and stand rigid, my whole body trembling violently. But outside, in the gloom of the street, M. S. was waiting, waiting with that fiendish glare of triumph that would brand me a man without courage. I could not return to face him, not though all the horrors of hell inhabited this gruesome place of mystery. And horrors must surely inhabit it, else how could one account for that fearful thing on the grating below? But I had been through horror before. I had seen a man, supposedly dead on the operating table, jerk suddenly to his feet and scream. I had seen a young girl, not long before, awake in the midst of an operation, with the knife already in her frail body. Surely, after those definite horrors, no _unknown_ danger would send me cringing back to the man who was waiting so bitterly for me to return. Those were the thoughts pregnant in my mind as I groped slowly, cautiously along the corridor of the upper floor, searching each closed door for the indistinct number 4167. The place was like the center of a huge labyrinth, a spider-web of black, repelling passages, leading into some central chamber of utter silence and blackness. I went forward with dragging steps, fighting back the dread that gripped me as I went farther and farther from the outlet of escape. And then, after losing myself completely in the gloom, I threw aside all thoughts of return and pushed on with a careless, surface bravado, and laughed aloud. * * * * * So, at length, I reached that room of horror, secreted high in the deeper recesses of the deserted warehouse. The number--God grant I never see it again!--was scrawled in black chalk on the door--4167. I pushed the half-open barrier wide, and entered. It was a small room, even as M. S. had forewarned me--or as the dead mind of that thing on the grate had forewarned M. S. The glow of my out-thrust match revealed a great stack of dusty boxes and crates, piled against the farther wall. Revealed, too, the black corridor beyond the entrance, and a small, upright table before me.