"All this time, as I stood still, the ground beneath my feet seemed to be moving. It was crawling towards me, and folding up underneath where I was standing. Frequently I had to move to avoid rocks that came at me and passed under my feet into nothingness.
"Then, all at once, I realized that I had been stepping constantly backward, to avoid the inclined wall as it shoved itself towards me. I turned to see what was behind, and horror made my flesh creep at what I saw. A black, forbidding wall, much like the incline in front, entirely encircled me. It was hardly more than half a mile away, and towered four or five thousand feet overhead.
"And as I stared in terror, I could see it closing in, the line of its upper edge coming steadily closer and lower. I looked wildly around with an overpowering impulse to run. In every direction towered this rocky wall, inexorably swaying in to crush me.
"I think I fainted. When I came to myself the scene had not greatly changed. I was lying at the bottom and against one wall of a circular pit, now about a thousand feet in diameter and nearly twice as deep. The wall all around I could see was almost perpendicular, and it seemed impossible to ascend its smooth, shining sides. The action of the drug had evidently worn off, for everything was quite still.
"My fear had now left me, for I remembered this circular pit quite well. I walked over to its center, and looking around and up to its top I estimated distances carefully. Then I took two more of the pills.
"Immediately the familiar, sickening, crawling sensation began again. As the walls closed in upon me, I kept carefully in the center of the pit. Steadily they crept in. Now only a few hundred feet away! Now only a few paces--and then I reached out and touched both sides at once with my hands.
"I tell you, gentlemen, it was a terrifying sensation to stand in that well (as it now seemed), and feel its walls closing up with irresistible force. But now the upper edge was within reach of my fingers. I leaped upward and hung for a moment, then pulled myself up and scrabbled out, tumbling in a heap on the ground above. As I recovered myself, I looked again at the hole out of which I had escaped; it was hardly big enough to contain my fist.