preliminary observations and go forth before the moon had dropped so far that the concentration in the condensers would fall below that necessary to keep the portal from closing.
I took out also a small spectroscope, and a few other instruments for the analysis of certain light manifestations and the testing of metal and liquid. Finally, I put aside my emergency medical kit.
I had hardly finished examining and adjusting these before O’Keefe and Huldricksson returned. They reported signs of a camp at least ten days old beside the northern wall of the outer court, but beyond that no evidence of others beyond ourselves on Nan–Tauach.
We prepared supper, ate and talked a little, but for the most part were silent. Even Larry’s high spirits were not in evidence; half a dozen times I saw him take out his automatic and look it over. He was more thoughtful than I had ever seen him. Once he went into the tent, rummaged about a bit and brought out another revolver which, he said, he had got from Da Costa, and a half-dozen clips of cartridges. He passed the gun over to Olaf.
At last a glow in the southeast heralded the rising moon. I picked up my instruments and the medical kit; Larry and Olaf shouldered each a short ladder that was part of my equipment, and, with our electric flashes pointing the way, walked up the great stairs, through the enclosures, and straight to the grey stone.
By this time the moon had risen and its clipped light shone full upon the slab. I saw faint gleams pass over it as of fleeting phosphorescence — but so faint were they that I could not be sure of the truth of my observation.
We set the ladders in place. Olaf I assigned to stand before the door and watch for the first signs of its opening — if open it should. The Becquerels were set within three-inch tripods, whose feet I had equipped with vacuum rings to enable them to hold fast to the rock.
I scaled one ladder and fastened a condenser over the boss; descended; sent Larry up to watch it, and, ascending the second ladder, rapidly fixed the other in its place. Then, with O’Keefe watchful on his perch, I on mine, and Olaf’s eyes fixed upon the moon door, we began our vigil. Suddenly there was an exclamation from Larry.
“Seven little lights are beginning to glow on this stone!” he cried.
But I had already seen those beneath my lens begin to gleam out with a silvery lustre. Swiftly the rays within the condenser began to thicken and increase, and as they did so the seven small circles waxed like stars growing out of the dusk, and with a queer — curdled is the best word I can find to define it — radiance entirely strange to me.
Beneath me I heard a faint, sighing murmur and then the voice of Huldricksson:
“It opens — the stone turns —”
I began to climb down the ladder. Again came Olaf’s voice:
“The stone — it is open —” And then a shriek, a wail of blended anguish and pity, of rage and despair — and the sound of swift footsteps racing through the wall beneath me!
I dropped to the ground. The moon door was wide open, and through it I caught a glimpse of a corridor filled with a faint, pearly vaporous light like earliest misty dawn. But of Olaf I could see — nothing! And even as I stood, gaping, from behind me came the sharp crack of a rifle; the glass of the condenser at Larry’s side flew into fragments; he dropped swiftly to the ground, the automatic in his hand flashed once, twice, into the darkness.
And the moon door began to pivot slowly, slowly back into its place!
I rushed toward the turning stone with the wild idea of holding it open. As I thrust my hands against it there came at my back a snarl and an oath and Larry staggered under the impact of a body that had flung itself straight at his throat. He reeled at the lip of the shallow cup at the base of the slab, slipped upon its polished curve, fell and rolled with that which had attacked him, kicking and writhing, straight through the narrowing portal into the passage!
Forgetting all else, I sprang to his aid. As I leaped I felt the closing edge of the moon door graze my side. Then, as Larry raised a fist, brought it down upon the temple of the man who had grappled with him and rose from the twitching body unsteadily to his feet, I heard shuddering past me a mournful whisper; spun about as though some giant’s hand had whirled me —
The end of the corridor no longer opened out into the moonlit square of ruined Nan–Tauach. It was barred by a solid mass of glimmering stone. The moon door had closed!
O’Keefe took a stumbling step toward the barrier behind us. There was no mark of juncture with the shining walls; the slab fitted into the sides as closely as a mosaic.
“It’s shut all right,” said Larry. “But if there’s a way in, there’s a way out. Anyway, Doc, we’re right in the pew we’ve been heading for — so why worry?” He grinned at me cheerfully. The man on the floor groaned, and he dropped to his knees beside him.
“Marakinoff!” he cried.
At my exclamation he moved aside, turning the face so I could see it. It was clearly Russian, and just as clearly its possessor was one of unusual force and intellect.
The strong, massive brow with orbital ridge unusually developed, the dominant, high-bridged nose, the straight lips with their more than suggestion of latent cruelty, and the strong lines of the jaw beneath a black, pointed beard all gave evidence that here was a personality beyond the ordinary.
“Couldn’t be anybody else,” said Larry, breaking in on my thoughts. “He must have been watching us over there from Chau-ta-leur’s vault all the time.”
Swiftly he ran practised hands over his body; then stood erect, holding out to me two wicked-looking magazine pistols and a knife. “He got one of my bullets through his right forearm, too,” he said. “Just a flesh wound, but it made him drop his rifle. Some arsenal, our little Russian scientist, what?”
I opened my medical kit. The wound was a slight one, and Larry stood looking on as I bandaged it.
“Got another one of those condensers?” he asked, suddenly. “And do you suppose Olaf will know enough to use it?”
“Larry,” I answered, “Olaf’s not outside! He’s in here somewhere!”
His jaw dropped.
“The hell you say!” he whispered.
“Didn’t you hear him shriek when the stone opened?” I asked.
“I heard him yell, yes,” he said. “But I didn’t know what was the matter. And then this wildcat jumped me —” He paused and his eyes widened. “Which way did he go?” he asked swiftly. I pointed down the faintly glowing passage.
“There’s only one way,” I said.
“Watch that bird close,” hissed O’Keefe, pointing to Marakinoff — and pistol in hand stretched his long legs and raced away. I looked down at the Russian. His eyes were open, and he reached out a hand to me. I lifted him to his feet.
“I have heard,” he said. “We follow, quick. If you will take my arm, please, I am shaken yet, yes —” I gripped his shoulder without a word, and the two of us set off down the corridor after O’Keefe. Marakinoff was gasping, and his weight pressed upon me heavily, but he moved with all the will and strength that were in him.
As we ran I took hasty note of
