clearing, since we could see now that on all the world below there moved only an occasional dark liquid-creature, the throngs we had seen before having unaccountably disappeared. Here and there above it moved a cube-ship, but none of these glimpsed us through the dusk, and in a moment more our cruisers had landed gently upon one of the smooth streets. There Jurt Tul and I swiftly stepped forth, for we had decided that we two alone could explore the comet-city more silently than a larger party. At once the cruisers swept back to wait for us in the dusk above, ready to make an attempt to escape from the comet should we be discovered. Then the amphibian and I moved swiftly along that silent street toward the great central plaza.
On each side of us loomed great massed machines at which we merely glanced as we hurried on. As we passed one of the pits that had puzzled me, though, I stepped to its edge, gazed down, then shrank back in horror! For in that shallow, smooth-walled pit there lay what seemed a great pool of thick black liquid unguessably deep, a pool formed by the liquid bodies of hundreds, perhaps thousands, of the liquid comet-creatures that had poured into it! I could glimpse the white eyes floating in it, here and there, but there was no other sign of life or movement in the mass, and as I saw that and thought of the rows upon rows of other similar pits that extended across the comet-city, I understood, and turned swiftly to Jurt Tul.
'Sleeping!' I exclaimed. 'In their night, their rest-period, they must all pour into these pits together-mingling their liquid bodies!'
Swiftly we shrank back from the great pit, moved on toward the clearing. Massed machines, grim and gleaming and towering, loomed all about us, half seen in the crimson dusk, and we passed scores of the great, liquid-filled pits in which slept the comet-creatures, but there was no sign of our two friends. Had they been destroyed? Dread filled me, dread intensified because I realized that soon the cornet-creatures would be ending their night, and turning on their white light of day, discovering us there on their world. Then, abruptly, Jurt Tul jerked me back from my forward stride, crouching silently with me upon the street, behind a mass of great mechanisms. For out of the darkness to our right had come the sound of something moving, something approaching us! Silently, tensely, we crouched there, and saw a dark shape moving stealthily down one of the branching streets toward us. It had turned from us, toward the great clearing ahead, when unexpectedly, as we crouched, my arm had brushed against the great machine beside us and touched something that moved beneath the touch, with a loud metallic clicking. Instantly that dark shape ahead had turned, and then was leaping straight toward us!
Before we could rise to meet it the rush of it had borne us downward, and as it did so I realized with a wild thrill that it was not a liquid-creature but a great and warm and fur-covered being, many-limbed, that had attacked us! Even as that fact penetrated into my brain our struggle had abruptly ceased, and we were staggering erect, Jurt Tul and I grasping the other.
'Gor Han!' I exclaimed. 'It's you!'
The great Betelgeusan's fur-covered body and strange features were clearly visible to us now as he grasped our own hands, his eyes wide.
'Khel Ken! Jurt Tul!' he whispered. 'I thought you destroyed in the battle!'
'We hid-escaped,' I explained to him swiftly. 'But you, Gor Han-how have you escaped? — and where's Najus Nar?'
He was silent a moment, then suddenly dragged us down into the deeper shadow of the great machines beside us. There, with the lurid light of the coma on his strange features, he spoke swiftly.
'Najus Nar is-living,' he said, 'but I will tell you what came upon us. You saw our ships fall in the battle over the city here, crashing down into it. At once these liquid comet-creatures were upon us, most of our crews having been killed in the crash, and but a few were left; but these being injured, too, they annihilated them with crimson bolts before we realized it, leaving but Najus Nar and myself, whom they wished, apparently, to question. Us they secured by metal bonds to one of the great machines, then came to us with little metal models, made of what seemed plastic gleaming metal, which could change instantaneously through a myriad different forms at their operation, and which they used for a rough communication with us. And through these and the things they explained to us, we learned, Najus Nar and I, something of the purpose and the past of these comet- creatures.
'Eons they had dwelt upon the central worlds of this giant comet that roamed the outer void, shaping those worlds to their will as it flashed on. They had used the coma's electrical energy for their own weapons, and had used it to produce light-vibrations, a white light which they turned on and off for their day and night. The coma's energy, indeed, was the source of all their world's activities, but as their giant comet plunged on through space, that energy, ever shot backward in the tail that drove the comet on, was dissipated faster and faster, the coma waning and dying as all comets wane and die in time. But one thing could save them: to absorb into the coma vast quantities of matter, which would be converted instantly into electrical energy to replenish the coma. Not far from the great comet at that time loomed a vast universe of suns, and if the comet were to crash through the universe its suns and worlds would replenish their waning coma and save their comet from death. They needed but to change the comet's course, to send it toward the universe instead of passing it, and to do this they set up a great comet-control.
'This comet-control was set on the top of a truncated pyramid in a clearing at the central world's center. It was a great horizontal disk, set parallel to their disk world, with a pointer that could be moved at will around the disk-dial. The position of the pointer, by means of great projectors to which it was connected, controlled the position of the comet's tail. If the pointer was at the dial's rear the tail would be shot forth from the great coma's rear also, driving it forward through space. If they turned the pointer to the left the tail would shoot from the coma's left, driving the comet to the right. They could thus, by means of the comet-control and the great projectors which controlled the tail's position, drive the comet in any direction at will. The only thing they could not do with it was to reverse the comet-control, to shoot out a new tail opposite to the old one, since the momentum or pressure of the new one would crush and annihilate the coma and its worlds between their great pressures. They could drive the comet to right or left at will, though, which was all that they needed, since now they drove it toward the universe of suns near them.
'Onward the giant comet drove to that universe, and soon crashed through it, its suns and worlds being sucked into the gigantic coma and annihilated there, converted instantly into electrical energy which restored the waning coma's glory. So onward through space with renewed power it flashed, through the great void between the galaxies, until ages later when its coma was again waning they drove it toward another universe, crashed through it likewise. And so through the eons, as ever the comet's glory, the coma's power, has waned, they have driven it through another universe, destroying that universe to restore it. On though the limitless void of outer space they have driven it, a cosmic vampire looting the life of universes to restore its own! And now, when the comet's glory has again waned, they have turned it toward our own galaxy, to destroy it as they have done countless others. And within less than a scant half-dozen hours now the comet will have thundered so close to our galaxy that no power in existence can turn it aside!
'All this we heard from the comet-creatures' communication with us, and then they proposed that we cast in our lot with them, forgetting our doomed universe, and help them build great cruisers and force-beam apparatus like those with which we had fought them. I refused, of course, not wishing to live under any conditions after our galaxy's death, but to my horror Najus Nar accepted the proposal! He joined them, not listening to my frantic words, and went away with them, leaving me in despair. Then when the gong sounded across their worlds that marked the end of the white light and the beginning of this night, I began to work frantically with the metal bonds that held me to the great machine, twisting and untwisting them until at last, but minutes ago, I managed to break them. They had counted on the bonds holding me, and had left no guard over me, so at once I started off toward the central clearing, toward the great comet-control, for a desperate last attempt at turning the comet aside with it. I heard you crouching there, thought you comet-creatures and sprang at you, and the rest you know.'
When Gor Han's deep whisper had ceased we were silent a moment, and surely never did stranger trio crouch in stranger place than we three, earth-man and amphibian Aldebaranian and great fur-clad Betelgeusan, there in the crimson dusk of the comet-city, all about us the pits that held its countless liquid-creatures and above us the glowing red coma which encompassed this world and was driving on toward our galaxy's doom. At last I broke the silence.
'Najus Nar with the comet-creatures!' I whispered. 'It's impossible! In all its record there have been no traitors in the Interstellar Patrol!'
Gor Han looked steadily, compassionately, at me. 'It is so, Khel Ken,' he said. 'I would not believe it had I not
