"Through the vibration-wall." I cried, as our ship raced out at utmost speed. "Out of the serpent-universe-and we may yet get to the Andromeda universe in time."

The eyes of Jhul Din and Korus Kan were as aflame with excitement as my own, at that moment, and from beneath came the triumphant shouts of our followers. There remained of the latter hardly more than a bare score, I knew-few enough to handle the great ship, but the control and operation of it were so simple that by standing alternate watches we could hold our course through space. Briefly I explained this to Korus Kan, he nodding assent, when from Jhul Din there came a cry that caused both of us to spin around toward him in swift alarm. The big Spican's eyes were fixed upon the space-chart above, and as we turned he raised an arm toward it.

"The five hundred serpent-ships." he cried. "They've come out through the great wall too-they're after us."

The blood in my veins seemed to chill with sudden renewal of our former tenseness and terror, as on the space-chart we saw, racing out after us from the dying universe, the five hundred-odd serpent-ships that had risen from the giant central world to pursue us, and that now, undeterred by the fate of the ten ships we had lured to destruction, were speeding out into the great void after us. Moments they had been delayed, apparently, by the confusion and chaos there in the opening between the space-forts, but though in those moments we had flashed far ahead their close-massed ships came on after us at their topmost speed-a great pursuit that they were carrying out into the void between the universes.

"They'll pursue us to the bitter end." I exclaimed, my eyes on the chart. "They'll go to any length rather than let us get to the Andromeda universe."

I wheeled about, my eyes seeking our speed-dials. Already we were traveling through the void at our own highest velocity, a full ten million light-speeds, but the shining mass of the Andromeda universe seemed infinitely distant in the blackness ahead, with that swift, relentless pursuit behind us. A moment more and Jhul Din strode out of the pilot room down to the great, throbbing generators beneath, striving to gain from them a fraction more of speed. For now was beginning, we knew, the most bitter of all chases, a stern chase with vast abysses of space lying between us and the universe that was our goal, and with the five hundred flying craft of the serpent-creatures close behind.

On-on-moment after moment, hour after dragging hour, our ship hummed through the awful void, flashing with each moment through countless millions of miles of the infinity of blackness and emptiness that lay about us, with the half-thousand ships of the serpent-creatures coming grimly on behind. The far-flung, dim-glowing dying universe behind us glowed even dimmer, diminishing in extent, too, as we shot onward, while before us the shining disk-mass of the Andromeda universe shone ever more brightly; yet it was with a terrifying slowness that that disk largened as we flashed toward it. Tensely I stood with Korus Kan in the pilot room, gazing toward it, and even then could not but reflect upon what a strange spectacle it would all have presented to any observer who could have seen it: a spectacle of one mighty ship pursued by a half-thousand, as it raced through the void from one universe to another, manned by a score of dissimilar beings drawn from the stars of still a third universe, and carrying with them its fate.

But it was with dark enough thoughts, as our ship flashed on for hour upon hour, that I myself contemplated the three universes that lay before and behind and beside us. Before us the Andromeda universe was shining in ever-increasing size and brilliance with each hour that we raced toward it; but what, I wondered, would we find in that universe even were we able to escape the swift and terrible pursuit behind? Was there any chance of finding in it, in the race that held sway over its suns and worlds, the help that could save our galaxy? Was it not possible that even were we able to reach it we would be treated by that race as merely other strangers and invaders from an alien universe?

My eyes swung, too, toward the far little glow of light in the blackness to our left, a patch of misty light that seemed very tiny in the stupendous blackness and emptiness of space that lay about it. Yet my mind's eye, leaping out across the terrific abysses that separated us from it, could see that little light-patch as it was, could make out the throngs of blazing stars that formed it-our galaxy, the giant suns and smaller stars and thronging, far-swinging worlds through which we had roamed with the ships of the Interstellar Patrol. And I could see it as it would be now, convulsed with panic fear, as from their great base of the Cancer cluster the vanguard of the serpent-invaders spread terror and destruction out over the neighboring suns, preparing the way for the mighty host of invaders that was to follow.

But it was when I turned, glancing back to where the dying universe of the serpent-people glowed dim and ominous behind us, decreasing steadily in size as we flashed from it, that my mood was darkest. In that mighty mass of dead and dying suns, I knew, there on the giant world that turned between that central triplet of great, dying suns, the serpent-races were completing their plans, were preparing to launch themselves across the void toward my own universe. Already their vast fleet of tens of thousands of ships was all but complete, and soon would be completed, too, that gigantic death-beam projector whose awful power no force could ever withstand. Our only chance of preventing the descent of that vast horde and their terrible weapon upon our galaxy was to reach the Andromeda universe and procure there, somehow, the aid with which we might return and crush the serpent-people in their own dying universe. And had we a chance even to reach the Andromeda universe, with the half-thousand craft of our serpent-pursuers driving relentlessly on our track?

* * *

In the hours that followed, it was as though all else had ceased to exist, so centered were our minds upon that remorseless pursuit. On and on we flashed, our throbbing, beating generators flinging us through the void with their utmost power, but behind came the serpent-ships at their topmost speed, too, and though for forty-eight hours we had raced through space we had covered hardly a third of the distance to the Andromeda universe. As I raised my eyes to the space-chart then, toward our single ship-dot and the swarm of dots behind it, a sharp, cold thrill ran through me. For now I saw that the gap of a few inches that separated us from them on the chart had lessened a little, the swarm drawing noticeably closer toward our single ship-dot. A moment I stared up at the chart in stunned silence; then, with realization, a cry broke from me.

"The serpent-ships!" I cried. "They're overtaking us!"

My cry brought Jhul Din back up into the pilot room, and standing together with eyes riveted upon the space-chart we saw clearly that with every moment, slowly but steadily, the serpent-ships behind were drawing nearer, though we were moving at our utmost speed. Our ship, battered and worn by its tremendous flight through the void from universe to universe, and by the space-fights it had come through, was a fraction slower than the new ships of our pursuers, and that fraction of difference in speed, we saw, was bringing them closer upon us with each passing minute. Yet there was a chance still, we knew, to gain the Andromeda universe before they overtook us; so still at utmost velocity we flashed on, toward the shining universe ahead.

On-on-the hours that followed, while we drove through the awful void with the serpent-ships behind closing slowly and inexorably in upon us, live in my memory only as a strange period of ceaseless, rushing flight, with our eyes always upon the space-chart and upon the brilliant disk-mass of light ahead. Twice we flashed through the outskirts of great heat-regions glowing there in the void, and once past the edge of one of the deadly areas of radio-active vibrations, but ever after passing them our ship swung back toward the universe ahead. That universe, as we hummed on hour upon hour, was changing from a glowing disk of light into a great mass of individual points of light, into a gigantic mass of stars that loomed in greater radiant splendor before us with each passing hour. Green and red and yellow and blue suns we could glimpse among its thronging thousands, and others still white-hot with youth, shining with ever greater brilliance as we drove through the void toward them.

Before us the great universe lay in all its true gigantic glory, when we had covered two-thirds of the distance to it, but by that time our eyes were not upon it at all, but upon the space-chart and the black void behind us; since in the intervening hours the serpent-ships had crept ever closer toward us, their swarm on the space-chart less than an inch behind our racing ship-dot. Even that little gap, in the hours that followed, was lessening, closing, while we three in the pilot room watched it in tense silence. At last, with the blazing mass of suns of the Andromeda universe stretched across the heavens but a dozen hours ahead, we saw that the serpent-swarm on the chart was all but touching our single ship-dot, saw that the end at last was at hand.

"They'll overhaul us in less than an hour." exclaimed Jhul Din. "We'll never even reach the Andromeda universe."

To his outburst we made no answer, gazing in silence up at the big space-chart, watching doom creep upon us. The serpent-swarm had crept still farther upon us until its foremost dots seemed touching our own ship-dot, its foremost racing craft in reach of our own. Then, gazing through the rear distance-windows that projected from the pilot room's sides, the big Spican uttered a low exclamation, pointing mutely backward as we turned toward him. And as we gazed we saw, far behind us there in the lightless void, a swarm of close-massed light-points that steadily was largening, was drawing nearer toward us, toward our doom. For it was the end, I knew. We had escaped death in a hundred forms in the last days, but this we could not escape, for with the Andromeda universe still hours away our chance of escape was gone. Dodge and turn as we might, they would corner us, would hem us in; and though we might destroy one or two of their half-thousand ships, by no miracle could we hope to escape the rest. For a moment a deathly silence held us as we stared back toward those nearing light-points, and then I whirled around to the order-tube.

"Battle-positions-all of the crew to the ray-tubes." I shouted, and as I turned back to the other two I cried to them, "We'll let some of them feel our rays before they end us."

I heard Jhul Din shout his approval, saw Korus Kan's eyes burning as he glanced back toward our pursuers, heard from beneath the cries of our crew as they took up their positions at the ray-tubes, ready to smite a last blow at our enemies before they overwhelmed us. Behind us in the black the onrushing serpent-ships had grown from light-points to great dark oval shapes with white-lit pilot rooms at their noses, the score of great disk attraction-ships racing on among them. Ever closer they were leaping, and I knew that in a moment more those disk-ships would be near enough to grasp us, would glow with attractive force and hold us helpless while the death-beams of the fighting-ships swept us. But as we tensely waited for the end, still flashing on at our own full speed, there was a sharp cry from Korus Kan, and we wheeled toward him to find him regarding the pilot room's walls with eyes suddenly alight with new hope.

"It's another radio-active vibration region." he cried, pointing toward the walls and controls that were beginning to flicker out with the strange, fluorescent light we had always dreaded. "If we plunge straight into it there's a chance we can shake off the pursuit."

I caught my breath at the suggestion but in an instant saw that he was right, that though we might meet death amid the disintegrating vibrations, we might perhaps escape and throw off our pursuers, from whom death was certain as things were.

"It's a chance," I exclaimed. "Head straight into the radio-active region, Korus Kan."

He glanced swiftly at the instruments before him, swerved our racing ship a little to the right, and then walls and floor and mechanisms about us were glowing with ever-waxing misty light as we drove in toward the great region's heart. I felt the same tingling force flooding through me that I had already once experienced, as our flying ship raced on, again swaying and spinning as it flashed through the mighty ether-currents whose meeting and collision formed the great region of vibrations about us, though outside was only the same blackness as before. With every moment, though, our ship, our mechanisms, our own bodies, were glowing with waxing light, while in the darkness behind I saw that the great swarm of ships racing after us was itself aglow now with light, as it, too, rushed into the great radio-active region after us. And still, with a courage that matched our own desperation, they were speeding after and closer to us, undeterred even by the crumbling death that flooded space all about them and us now.

Glowing ship and glowing bodies, force that rapidly was overcoming us with a dizzy nausea and that was crumbling the walls and machinery about us, the gathered suns of the Andromeda universe far ahead and the glowing half-thousand pursuing ships just behind-all these were but a mad chaos in our minds as we reeled on, farther and farther into the mighty radio-active region. I heard even above the roaring of our generators a clatter of falling metal somewhere toward the ship's rear, while even about us the walls and all else were crumbling, like sugar in water, glowing and disintegrating, as our whole ship was beginning to break up. Now, too, as the great swarm of ships behind raced ever closer a score or more of their number had drawn level with us, on our right, attaining that position by slanting in to cut us off when we had swerved in toward the radio-active region. And as pursued and pursuers raced on, all glowing and disintegrating alike, that score of ships to our right was pressing ever closer toward us.

Nearer they came, and then from their glowing ships toward our own stabbed the pale death-beams, sweeping about us as we flashed on, a shining mark. As they did so, though, our own red shafts burned out swiftly, two of those attacking ships flaring to nothingness beneath them, while with a swift turn to the left Korus Kan had avoided the pale beams. That turn, though, took us now every moment outward once more from the radio-active region's center, forcing us out once more into clear space where the serpent-ships could annihilate us without danger to themselves. Out and out we flashed, and though our ship and all in it still glowed with the fluorescent light, that glow was waning, and the clang of falling metal from beneath, from the ship's disintegrating sides had ceased. Out-out-the score of ships to our right joining with the greater mass behind us again, and all drawing closer toward us, until the tingling nausea that had filled us had vanished, the glowing light of our ships and theirs vanishing likewise. Then, in one great mass, they were leaping again upon us.

Our lives at last within their grasp, they flashed after us and toward us, and I knew that an instant more would see them about us, their death-beams striking at us from all around as they encircled us. I gazed ahead for a moment, to where the giant universe of Andromeda stretched like a great rampart of burning suns across the black, cold heavens, still hours away from us, and then gazed back to where the close-massed hundreds of serpent-ships leapt after and upon us, the death-beam tubes in their sides already swinging toward us. Then in me, at that instant of onrushing doom, there flamed up a strange, wild rage, a fierce, utter fury that had grown in me during all the struggles and flights that had been ours since first we had met these serpent-creatures. I wheeled around to Jhul Din and Korus Kan, my anger breaking from me in a fiery shout.

"Turn the ship square around and halt, Korus Kan!" I cried. "We of the Interstellar Patrol are not going to be picked off as we run-we're going to turn and face them head on."

Korus Kan's eyes flamed at my cry, his hands moved swiftly on the controls, and then our ship had curved suddenly about and had slowed and stopped, swinging around and hanging motionless in space, facing our enemies. Even as we had curved and stopped, they too had swiftly halted, as though suspicious for the moment of some trap, and hung before us in the black gulf of space, facing us. Then there was an instant of utter stillness and silence, as there in the void we faced them, our ship motionless in space, we three in the pilot room gazing toward their own great swarm of ships hanging motionless before us; the mighty Andromeda universe flaming in the heavens behind us, now, and the far, dim glow of the dying serpent-universe in the blackness ahead, and the misty little circle of light that was our own galaxy away to the right; all these lay about us in a silence that was the silence of doom. For a single moment the great tableau held, and then, disdaining to use their attraction-ships upon us now, the great swarm of serpent-ships leapt as one toward us, their hundreds of death-beams stabbing toward us.

But as they did so, as they sprang upon us there in space, there leapt from above and behind us a mighty swarm of other ships-long, slender, flat, gleaming ships entirely different from the oval-shaped serpent-craft, or even from the cigar-like ships of our own galaxy-long, flat ships like none we had ever seen before, that flashed down over and past us straight upon the serpent-fleet! From the sides of these strange new ships there projected thick, squat cylinders that were pointed now toward the serpent-ships before us, and though no ray or beam could be seen issuing from those cylinders, the serpent-ships at which they were aimed were crumpling, were contracting and folding up into shapeless masses of crumpled metal, as though crushed in the grasp of a giant hand! And as that mighty swarm of strange, flat ships flashed down upon the serpent-fleet that reeled back and recoiled from its terrific blows, I heard a wild cry from Korus Kan, as he and Jhul Din stared out with me.

"Strange ships attacking our pursuers." he cried. "They're ships that have come out from the Andromeda universe to save us from the serpent-creatures' pursuit."