It was no open plaza or square, but a pit-a shallow, circular pit not more than a hundred feet in depth but all of a mile in diameter, and we stood at the rim or edge of it. The floor was smooth and flat, and upon that floor there lay a grouped mass of hundreds of half-globes or hemispheres, each fifty feet in diameter, which were resting upon their flat bases with their curving sides uppermost. Each of these hemispheres was shining with light, but it was very different light from the feeble glow of the buildings and streets around us, an intensely brilliant blue radiance which was all but blinding to our eyes. From these massed, radiant hemispheres came the loud droning we had heard, and now we saw, at the pit's farther edge, a cylindrical little room or structure of metal which was supported several hundred feet above the pit's floor by a single slender shaft of smooth round metal, like a great bird-cage. And toward this cage-structure Hurus Hol was pointing now, his eyes flashing.

"It's the switch-board of the thing!" he cried. "And these brilliant hemispheres-the unheard-of space-path of this dark star-it's all clear now! All-"

He broke off, suddenly, as Nal Jak sprang back, uttering a cry and pointing upward. For the moment we had forgotten the hovering cones above the city, and now one of them was slanting swiftly downward, straight toward us.

We turned, ran back, and the next moment an etheric bomb crashed down upon the spot where we had stood, exploding silently in a great flare of light. Another bomb fell and flared, nearer, and then I turned with sudden fierce anger and aimed the little ray-projector in my hand at the hovering cone above. The brilliant little beam cut across the dark shape; the black cone hovered still for a moment, then crashed down into the street to destruction. But now, from above and beyond, other cones were slanting swiftly down toward us, while from the pyramidal buildings beside us hordes of the black tentacle-creatures were pouring out in answer to the alarm.

In a solid, resistless swarm they rushed upon us. I heard a yell of defiance from Dal Nara, beside me, the hiss of our rays as they clove through the black masses in terrible destruction, and then they were upon us. A single moment we whirled about in a wild melee of men and cone-creatures, of striking human arms and coiling tentacles; then there was a shout of warning from one of my friends, something hard descended upon my head with crushing force, and all went black before me.

IV

Faint light was filtering through my eyelids when I came back to consciousness. As I opened them I sat weakly up, then fell back. Dazedly I gazed about me. I was lying in a small, square room lit only by its own glowing walls and floor and ceiling, a room whose one side slanted steeply upward and inward, pierced by a small barred window that was the only opening. Opposite me I discerned a low door of metal bars, or grating, beyond which lay a long, glowing-walled corridor. Then all these things were suddenly blotted out by the anxious face of Hurus Hol, bending down toward me.

"You're awake!" he exclaimed, his face alight. "You know me, Ran Rarak?"

For answer I struggled again to a sitting position, aided by the arm of Dal Nara, who had appeared beside me. I felt strangely weak, exhausted, my head throbbing with racing fires.

"Where are we?" I asked, at last. "The fight in the city-I remember that-but where are we now? And where's Nal Jak?"