Not being able to answer, I remained silent. But a strange suspicion, which had been forming in my mind, was gradually deepening; and involuntarily I shuddered once more and pressed closer to my friend—nor was I reassured by the renewed trembling of the earth which from time to time interrupted our ruminations.
I am afraid that grim conjectures came into the mind of Clay also, for he remained tense and silent for many minutes as we continued to fumble, like blind men, down those uncanny subterranean corridors.
"The devil take us both!" he at last muttered, with an attempted levity that did not serve to conceal his alarm. "You'd think we were going straight down to Dante's Inferno! Why, I can almost feel the little imps dancing in the darkness all about us!"
"The imps be damned!" I snapped in unseemly irritation.
"Most likely, that's what we'll be," he returned, wryly. And then, in soberer tones, he spoke again.
"But seriously, old man, where do you suppose we are?—in the pit of some extinct volcano?"
"Possibly—but that doesn't explain why the walls are so smooth and even."
"No, it doesn't. However, mightn't it be the channel of a dried-up subterranean river? In the course of ages, the water might have washed the walls smooth."
"It might have," I conceded, briefly. Yet deep within me, there was the feeling, the persistent feeling, that it was not water that had hollowed out the passageway.
For ten or fifteen minutes we plodded on without a word, moving at a snail's pace in our anxiety, and not aware of any change in our environment. The walls were still as polished and regular as ever; the blackness was as absolute and as unbroken; the occasional jarring of the earth continued at uneven intervals, growing a little more pronounced than before, but disturbing us less, since we were now becoming used to it.