That was a tedious job and a distasteful one. For many minutes I gnawed away at those thick cords like a dog on a bone. It was considerably later that I discovered what those cords were made of; thank Heaven, I was ignorant of it at the time! All I knew was that they were, to use one of Harry's phrases, "tough as rats."

I did not dare pull with my wrists, for fear they would fly suddenly apart and betray me to the unseen watchers. It was necessary to cut clear through with my teeth, and more than once I was on the point of giving it up. There was a nauseating, rancid taste to the stuff, but I dared not even raise my head to expectorate.

Finally my teeth met; the cords were severed. I felt carefully about with my tongue to make sure there were no others; then, without moving my hands in the slightest degree, carefully raised my head.

It was then that I first noticed--not light, but a thinning out of the darkness. It was, of course, merely the adjustment of my eyes to the new conditions. I could make out no forms surrounding me, but, looking down, I could clearly distinguish the outline of my hands as they lay on the ground before me.

And, again looking up, I fancied that I could see, some twenty or thirty feet to the right, that the darkness again became suddenly dense and impenetrable.

"That must be a wall," I muttered, straining my eyes toward it.

"What's that?" asked Harry sharply.

Obedient to my instructions, the lad had lain perfectly motionless and silent for over an hour, for it must have taken me at least that long to gnaw through the cords.

"I said that must be a wall. Look, Harry, about thirty feet to the right. Doesn't it appear to you that way?"

"By Jove," he exclaimed after a moment of silence, "it's getting light!

Look!"

I explained that, instead of "it's getting light," his eyes were merely becoming accustomed to the darkness.

"But what do you think of that? Is it a wall?"

After a moment's silence he answered: "Ye-es," and then more positively: "Yes. But what good does that do us?"

"That's what I am about to tell you. Listen! I've cut the cords on my wrists, and I'm going to get my knife--"

"How the deuce did you manage that?" Harry interrupted.

"With my teeth. I've been rather busy. I'm going to get my knife--cautiously, so they won't suspect if they are watching us. We must lie close together on our sides, facing each other, so I can cut the thongs on your wrists without being seen. Then you are to get your knife--carefully. Do you understand?"

"Yes."

For the first time there was fight in Harry's voice; the curious, barely perceptible tremor of the man of courage.

"All right. Go easy."

We went about the thing slowly, turning but an inch at a time; a second mistake might prove fatal. We heard no sound of any kind, and ten minutes later we were lying flat on our backs side by side, keeping our hands hidden between our bodies, that the absence of the thongs might not be discovered. Each of us held in his right hand the hilt of a six inch knife. Cold steel is by no means the favorite weapon of an American, but there are times--

"Have you got your knife, Harry?"

"Yes."

"Good! Now listen close and act quick. When I give the word reach down and grasp the cords round your ankles in your left hand, then cut them through with one stroke. Then to your feet; grasp my jacket, and together to the wall--that's for our backs. And then--let 'em come!"

"All right, old man."

"Don't waste any time; they'll probably start for us the instant we sit up. Be sure you get your feet free at the first stroke; feel them well with your left hand first. Are you ready?"

"Yes." And his voice was now calm and perfectly steady.

"Then--one, two, three--go!"

We bent and cut and sprang to our feet, and dashed for the wall. There was a sound of rushing feet--our backs hugged the kindly rock--I heard Harry's shout, "Here they come!"--dim, rushing forms--fingers clutching at my throat.

I felt the blade of my knife sink into soft and yielding flesh, and a warm, thick liquid flow over my hand and arm.

Chapter VIII.

THE DANCE OF THE SUN.

It seemed to me then in the minutes that followed that there were thousands of black demons in that black hole. At the first rushing impact I shouted to Harry: "Keep your back to the wall," and for response I got a high, ringing laugh that breathed the joy of battle.

The thing was sickening. Harry is a natural fighting man; I am not.

Without the wall at our backs we would have been overpowered in thirty seconds; as it was, we were forced to handle half a dozen of them at once, while the others surged in from behind. They had no weapons, but they had the advantage of being able to see us.

They clutched my throat, my arms, my legs, my body; there was no room to strike; I pushed the knife home. They fastened themselves to my legs and feet and tried to bring me down from beneath; once, in slashing at the head of one whose teeth were set in my calf, I cut myself on the knee. It was difficult to stand in the wet, slippery pool that formed at my feet.

Suddenly I heard a sound that I understood too well--the curious, rattling sound of a man who is trying to call out when he is being strangled.

"Harry!" I cried, and I fought like a wild man to get to him, with knife, feet, hands, teeth. I reached his coat, his arm; it was dangerous to strike so near him in the dark, but I felt him sinking to the ground.

Then I found the taut, straining fingers about his throat, and lunged forward with the knife--and the fingers relaxed.

Again we were fighting together side by side.

As their bodies fell in front of us we were pressed harder, for those behind climbed up on the corpses of their fellows and literally descended on our heads from the air. We could not have held out much longer; our breath was coming in quick, painful gasps; Harry stumbled on one of the prostrate brutes and fell; I tried to lift him and was unequal to the task.

It appeared to be the end.

Suddenly there rang throughout the cavern a sound as of a gigantic, deep-toned bell. The walls sent it back and forth with deafening echoes; it was as though the mountain had descended with one tremendous crash into its own bowels.

As though by magic, the a.s.sault ceased.

The effect was indescribable. We could see nothing; we merely became suddenly aware that there were no longer hands clutching at our throats or hairy bodies crushing us to the ground. It was as though the horde of unseen devils had melted into thin air. There were movements on the ground, for many of them had been wounded; a man cannot always reach the spot in the dark. This lasted for two or three minutes; they were evidently removing those who still had life in them, for the straining breath of men dragging or lifting burdens was plainly audible.

Gradually that, too, died away with the last reverberations of the mysterious sound that had saved us, and we found ourselves alone--or at least unmolested--for in the darkness we could see nothing, except the dim outlines of the prostrate forms at our feet.

The cavern was a shambles. The smell was that of a slaughter-house. I had had no idea of the desperateness of our defense until I essayed to scramble over the heap of bodies to dry ground; I shuddered and grew faint, and Harry was in no better case.

Worse, he had dropped his knife when we stumbled, and we were forced to grope round in that unspeakable mess for many minutes before we found it.

"Are you hurt, lad?" I asked when once we stood clear.

"Nothing bad, I think," he answered. "My throat is stiff, and two or three of the brutes got their teeth in me. In the name of Heaven, Paul, what are they? And what was that bell?"