"Do you remember," I asked by way of answer, "a treatise of Aristotle concerning which we had a discussion one day? Its subject was the hypnotic power possessed by the eyes of certain reptiles. I laughed the idea to scorn; you maintained that it was possible. Well, I agree with you; and I'd like to have about a dozen of our modern skeptical scientists in this cave with me for about five minutes."

"But what is it? A reptile!" Harry exclaimed. "The thing is as big as a house!"

"Well, and why not? I should guess that it is about thirty feet in height and forty or fifty in length. There have been species, now extinct, several times as large."

"Then you think it is just--just an animal?" put in Desiree.

"What did you think it was?" I nearly smiled. "An infernal machine?"

"I don't know. Only I have never before known what it was to fear."

A discussion which led us nowhere, but at least gave us the sound of one another's voices.

We pa.s.sed many hours in that manner. Utterly blank and wearisome, and all but hopeless. I have often wondered at the strange tenacity with which we clung to life in conditions that made of it a burden almost insupportable; and with what chance of relief?

The instinct of self-preservation, it is called by the learned, but it needs a stronger name. It is more than an instinct. It is the very essence of life itself.

But soon we were impelled to action by something besides the desire to escape from the cavern: the pangs of hunger. It had been many hours since we had eaten; I think we had fasted not less than three or four days.

Desiree began to complain of a dizziness in her temples, and to weaken with every hour that pa.s.sed. My own strength did not increase, and I saw that it would not unless I could obtain nourishment. Harry did not complain, but only because he would not.

"It is useless to wait longer," I declared finally. "I grow weaker instead of stronger."

We had little enough with which to burden ourselves. There were three spears, two of which Harry had brought, and myself the other. Harry and I wore only our woolen undergarments, so ragged and torn that they were but sorry covering.

Desiree's single garment, made from some soft hide, was held about her waist by a girdle of the same material. The upper half of her body was bare. Her hair hung in a tangled ma.s.s over her shoulders and down her back. None of us had any covering for our feet.

We crossed the stream, using the spears as staffs; but instead of advancing across the middle of the cavern we turned to the left, hugging the wall. Harry urged us on, saying that he had already searched carefully for an exit on that side, but we went slowly, feeling for a break in the wall. It was absolutely smooth, which led me to believe that the cavern had at one time been filled with water.

We reached the farther wall and, turning to the right, were about to follow it.

"This is senseless," said Harry impatiently. "I tell you I have examined this side, too; every inch of it."

"And the one ahead of us, at right angles to this?" I asked.

"That too," he answered.

"And the other--the one to the right of the stream?"

"No. I--I didn't go there."

"Why didn't you say so?" I demanded.

"Because I didn't want to," he returned sullenly. "You can go there if you care to; I don't. It was from there that--it came."

I did not answer, but pushed forward, not, however, leaving the wall.

Perhaps it was cowardly; you are welcome to the word if you care to use it. Myself, I know.

Another half-hour and we reached the end of the lane by which we had first entered the cavern. We stood gazing at it with eyes of desire, but we knew how little chance there was of the thing being unguarded at the farther end. We knew then, of course, and only too well, why the Incas had not followed us into the cavern.

"Perhaps they are gone," said Harry. "They can't stay there forever.

I'm going to find out."

He sprang on the edge of a boulder at the mouth of the pa.s.sage and disappeared on the other side. In fifteen minutes he returned, and I saw by the expression on his face that there was no chance of escape in that direction.

"They're at the other end," he said gloomily; "a dozen of 'em. I looked from behind a rock; they didn't see me. But we could never get through."

We turned then, and proceeded to the third wall and followed it. But we really had no hope of finding an exit since Harry had said that he had previously explored it. We were possessed, I know, by the same thought: should we venture to follow the fourth wall? Alone, none of us would have dared; but the presence of the others lessened the fear of each.

Finally we reached it. The corner was a sharp right angle, and there were rifts and crevices in the rock.

"This is limestone," I said, "and if we find an exit anywhere it will be here."

I turned to the right and proceeded slowly along the wall, feeling its surface with my hand.

We had advanced in this manner several hundred yards when Desiree suddenly sprang forward to my side.

"See!" she cried, pointing ahead with her spear.

I followed the direction with my eye, and saw what appeared to be a sharp break in the wall.

It was some fifty feet away. We reached it in another moment, and I think none of us would have been able to express the immeasurable relief we felt when we saw before us a broad and clear pa.s.sage leading directly away from the cavern. It was very dark, but we entered it almost at a run.

I think we had not known the extent of our fear of that thing in the cavern until we found the means of escape from it.

We had gone about a hundred feet when we came to a turn to the left.

Harry stumbled against the corner, and we halted for an instant to wait for him.

Then we made the turn, side by side--and then we came to a sudden and abrupt stop, and a simultaneous gasp of terror burst from our lips.

Not three feet in front of us, blocking the pa.s.sage completely, stood the thing we thought we had escaped!

The terrible, fiery eyes rolled from side to side as they stared straight into our own.

Chapter XVIII.

A VICTORY AND A CONVERSATION.

We stood for a long moment rooted to the spot, unable to move. Then, calling to Harry and grasping Desiree by the arm, I started to turn.

But too late. For Desiree, inspired by a boundless terror, suddenly raised her spear high above her head and hurled it straight at the glowing, flashing eyes.

The point struck squarely between them with such force that it must have sunk clear to the shaft. The head of the monster rolled for an instant from side to side, and then, before I was aware of what had happened, so rapid was the movement, a long, snakelike coil had reached out through the air and twisted itself about Desiree's body.

As she felt the thing tighten about her waist and legs she gave a scream of terror and twisted her face round toward me. The next instant the snaky tentacle had dragged her along the ground and lifted her to the head of the monster, where her white body could be seen in sharp outline sprawling over its black form, between the terrible eyes.