But since it had been impossible for me to penetrate here, would it not be equally impossible for me to get out again, except upon the "Terror?" Ah, if the mists would but lift! Perhaps I should recognize the place. What was as yet a mere hypothesis, would become a starting point to act upon.

However, since I had freedom to move about, since neither the captain nor his men paid any heed to me, I resolved to explore the hollow. The three of them were all in the grotto toward the north end of the oval. Therefore I would commence my inspection at the southern end.

Reaching the rocky wall, I skirted along its base and found it broken by many crevices; above, arose more solid rocks of that feldspar of which the chain of the Alleghanies largely consists. To what height the rock wall rose, or what was the character of its summit, was still impossible to see. I must wait until the sun had scattered the mists.

In the meantime, I continued to follow along the base of the cliff. None of its cavities seemed to extend inward to any distance. Several of them contained debris from the hand of man, bits of broken wood, heaps of dried grasses. On the ground were still to be seen the footprints that the captain and his men must have left, perhaps months before, upon the sand.

My jailers, being doubtless very busy in their cabin, did not show themselves until they had arranged and packed several large bundles. Did they purpose to carry those on board the "Terror?" And were they packing up with the intention of permanently leaving their retreat?

In half an hour my explorations were completed and I returned toward the center. Here and there were heaped up piles of ashes, bleached by weather. There were fragments of burned planks and beams; posts to which clung rusted iron-work; armatures of metal twisted by fire; all the remnants of some intricate mechanism destroyed by the flames.

Clearly at some period not very remote the hollow had been the scene of a conflagration, accidental or intentional. Naturally I connected this with the phenomena observed at the Great Eyrie, the flames which rose above the crest, the noises which had so frightened the people of Pleasant Garden and Morganton. But of what mechanisms were these the fragments, and what reason had our captain for destroying them?

At this moment I felt a breath of air; a breeze came from the east. The sky swiftly cleared. The hollow was filled with light from the rays of the sun which appeared midway between the horizon and the zenith.

A cry escaped me! The crest of the rocky wall rose a hundred feet above me. And on the eastern side was revealed that easily recognizable pinnacle, the rock like a mounting eagle. It was the same that had held the attention of Mr. Elias Smith and myself, when we had looked up at it from the outer side of the Great Eyrie.

Thus there was no further doubt. In its flight during the night the airship had covered the distance between Lake Erie and North Carolina. It was in the depth of this Eyrie that the machine had found shelter! This was the nest, worthy of the gigantic and powerful bird created by the genius of our captain! The fortress whose mighty walls none but he could scale! Perhaps even, he had discovered in the depths of some cavern, some subterranean passage by which he himself could quit the Great Eyrie, leaving the "Terror" safely sheltered within.

At last I saw it all! This explained the first letter sent me from the Great Eyrie itself with the threat of death. If we had been able to penetrate into this hollow, who knows if the secrets of the Master of the World might not have been discovered before he had been able to set them beyond our reach?

I stood there, motionless; my eyes fixed on that mounting eagle of stone, prey to a sudden, violent emotion. Whatsoever might be the consequences to myself, was it not my duty to destroy this machine, here and now, before it could resume its menacing flight of mastery across the world!

Steps approached behind me. I turned. The inventor stood by my side, and pausing looked me in the face.

I was unable to restrain myself; the words burst forth -- "The Great Eyrie! The Great Eyrie!"

"Yes, Inspector Strock."

"And you! You are the Master of the World?"

"Of that world to which I have already proved myself to be the most powerful of men."

"You!" I reiterated, stupefied with amazement.

"I," responded he, drawing himself up in all his pride, "I, Robur--Robur, the Conqueror!"