We had proceeded in this manner some hundred yards or more, advancing cautiously, when we came to a break in the wall. A few feet farther the wall began again.
“It’s a tunnel,” said Harry.
I nodded, forgetting he could not see me. “Shall we take it?”
“Anything on a chance,” he answered, and we entered the passage.
It was quite narrow—so narrow that we were forced to advance very slowly, feeling our way to avoid colliding with the walls. The ground was strewn with fragments of rock, and a hasty step meant an almost certain fall and a bruised shin. It was tedious work and incredibly fatiguing.
We had not rested a sufficient length of time to allow our bodies to recuperate from the struggle with the torrent; also, we began to feel the want of food. Harry was the first to falter, but I spurred him on. Then he stumbled and fell and lay still.
“Are you hurt?” I asked anxiously, bending over him.
“No,” was the answer. “But I’m tired—tired to death—and I want to sleep.”
I was tempted myself, but I brought him to his feet, from some impulse I know not what. For what was the use? One spot was as good as another. However, we struggled on.
Another hour and the passage broadened into a clearing. At least so it seemed; the walls abruptly parted to the right and left. And still the impenetrable, maddening darkness and awful silence!
We gave it up; we could go no farther. A few useless minutes we wasted, searching for a soft spot to lie on—moss, reeds, anything. We found none, of course; but even the hard, unyielding rock was grateful to our exhausted bodies. We lay side by side, using our ponchos for pillows; our clothing at least was dry.
I do not know how long I slept, but it seemed to me that I had barely dozed off when I was awakened by something—what?
There was no sound to my strained ears. I sat up, gazing intently into the darkness, shuddering without apparent reason. Then I reflected that nothing is dangerous to a man who faces death, and I laughed aloud—then trembled at the sound of my own voice. Harry was in sound sleep beside me; his regular breathing told of its depth.
Again I lay down, but I could not sleep. Some instinct, long forgotten, quivered within me, telling me that we were no longer alone. And soon my ear justified it.
At first it was not a sound, but the mere shadow of one. It was rhythmic, low, beating like a pulse. What could it be? Again I sat up, listening and peering into the darkness. And this time I was not mistaken—there was a sound, rustling, sibilant.
Little by little it increased, or rather approached, until it sounded but a few feet from me on every side, sinister and menacing. It was the silent, suppressed breathing of something living—whether animal or man—creeping ever nearer.
Then was the darkness doubly horrible. I sat paralyzed with my utter helplessness, though fear, thank Heaven, did not strike me! I could hear no footstep; no sound of any kind but that low, rushing breathing; but it now was certain that whatever the thing was, it was not alone.