it and withdrew my hand quickly for at the contact every nerve in my arm tingled as though a shock of frozen electricity had passed through it. It was not cold as we know cold. It was a chill force — the phrase I have used — frozen electricity — describes it better than anything else. Stanton looked at me oddly.
“‘So you felt it too,’ he said. ‘I was wondering whether I was developing hallucinations like Thora. Notice, by the way, that the blocks beside it are quite warm beneath the sun.’
“We examined the slab eagerly. Its edges were cut as though by an engraver of jewels. They fitted against the neighbouring blocks in almost a hair-line. Its base was slightly curved, and fitted as closely as top and sides upon the huge stones on which it rested. And then we noted that these stones had been hollowed to follow the line of the grey stone’s foot. There was a semicircular depression running from one side of the slab to the other. It was as though the grey rock stood in the centre of a shallow cup — revealing half, covering half. Something about this hollow attracted me. I reached down and felt it. Goodwin, although the balance of the stones that formed it, like all the stones of the courtyard, were rough and age-worn — this was as smooth, as even surfaced as though it had just left the hands of the polisher.
“‘It’s a door!’ exclaimed Stanton. ‘It swings around in that little cup. That’s what makes the hollow so smooth.’
“‘Maybe you’re right,’ I replied. ‘But how the devil can we open it?’
“We went over the slab again — pressing upon its edges, thrusting against its sides. During one of those efforts I happened to look up — and cried out. A foot above and on each side of the corner of the grey rock’s lintel was a slight convexity, visible only from the angle at which my gaze struck it.
“We carried with us a small scaling-ladder and up this I went. The bosses were apparently nothing more than chiseled curvatures in the stone. I laid my hand on the one I was examining, and drew it back sharply. In my palm, at the base of my thumb, I had felt the same shock that I had in touching the slab below. I put my hand back. The impression came from a spot not more than an inch wide. I went carefully over the entire convexity, and six times more the chill ran through my arm. There were seven circles an inch wide in the curved place, each of which communicated the precise sensation I have described. The convexity on the opposite side of the slab gave exactly the same results. But no amount of touching or of pressing these spots singly or in any combination gave the slightest promise of motion to the slab itself.
“‘And yet — they’re what open it,’ said Stanton positively.
“‘Why do you say that?’ I asked.
“‘I— don’t know,’ he answered hesitatingly. ‘But something tells me so. Throck,’ he went on half earnestly, half laughingly, ‘the purely scientific part of me is fighting the purely human part of me. The scientific part is urging me to find some way to get that slab either down or open. The human part is just as strongly urging me to do nothing of the sort and get away while I can!’
“He laughed again — shamefacedly.
“‘Which shall it be?’ he asked — and I thought that in his tone the human side of him was ascendant.
“‘It will probably stay as it is — unless we blow it to bits,’ I said.
“‘I thought of that,’ he answered, ‘and I wouldn’t dare,’ he added soberly enough. And even as I had spoken there came to me the same feeling that he had expressed. It was as though something passed out of the grey rock that struck my heart as a hand strikes an impious lip. We turned away — uneasily, and faced Thora coming through a breach on the terrace.
“‘Miss Edith wants you quick,’ she began — and stopped. Her eyes went past me to the grey rock. Her body grew rigid; she took a few stiff steps forward and then ran straight to it. She cast herself upon its breast, hands and face pressed against it; we heard her scream as though her very soul were being drawn from her — and watched her fall at its foot. As we picked her up I saw steal from her face the look I had observed when first we heard the crystal music of Nan–Tauach — that unhuman mingling of opposites!”
CHAPTER IV
THE FIRST VANISHINGS
“We carried Thora back, down to where Edith was waiting. We told her what had happened and what we had found. She listened gravely, and as we finished Thora sighed and opened her eyes.
“‘I would like to see the stone,’ she said. ‘Charles, you stay here with Thora.’ We passed through the outer court silently — and stood before the rock. She touched it, drew back her hand as I had; thrust it forward again resolutely and held it there. She seemed to be listening. Then she turned to me.
“‘David,’ said my wife, and the wistfulness in her voice hurt me —‘David, would you be very, very disappointed if we went from here — without trying to find out any more about it — would you?’
“Walter, I never wanted anything so much in my life as I wanted to learn what that rock concealed. Nevertheless, I tried to master my desire, and I answered —‘Edith, not a bit if you want us to do it.’
“She read my struggle in my eyes. She turned back toward the grey rock. I saw a shiver pass through her. I felt a tinge of remorse and pity!
“‘Edith,’ I exclaimed, ‘we’ll go!’
“She looked at me again. ‘Science is a jealous mistress,’ she quoted. ‘No, after all it may be just fancy. At any rate, you can’t run away. No! But, Dave, I’m going to stay too!’
“And there was no changing her decision. As we neared the others she laid a hand on my arm.
“‘Dave,’ she said, ‘if there should be something — well — inexplicable tonight — something that seems — too dangerous — will you promise to go back to our own islet tomorrow, if we can — and wait until the natives return?’
“I promised eagerly — the desire to stay and see what came with the night was like a fire within me.
“We picked a place about five hundred feet away from the steps leading into the outer court.
“The spot we had selected was well hidden. We could not be seen, and yet we had a clear view of the stairs and the gateway. We settled down just before dusk to wait for whatever might come. I was nearest the giant steps; next me Edith; then Thora, and last Stanton.
“Night fell. After a time the eastern sky began to lighten, and we knew that the moon was rising; grew lighter still, and the orb peeped over the sea; swam into full sight. I glanced at Edith and then at Thora. My wife was intently listening. Thora sat, as she had since we had placed ourselves, elbows on knees, her hands covering her face.
“And then from the moonlight flooding us there dripped down on me a great drowsiness. Sleep seemed to seep from the rays and fall upon my eyes, closing them — closing them inexorably. Edith’s hand in mine relaxed. Stanton’s head fell upon his breast and his body swayed drunkenly. I tried to rise — to fight against the profound desire for slumber that pressed on me.
“And as I fought, Thora raised her head as though
