the other sun's system, would be annihilated by the collision, of course, would perish in that flaming shock of suns. But the outermost planets of Alto, which lay in orbits billions of miles from it, would be safe enough and would take up their orbits around this great new sun in place of Alto. And on these planets the globe-people could exist for eons, supported by the heat of the great new sun. It was a perfect plan, and required only that their own sun, Alto, be swerved from its path just enough to make it crash into the other sun instead of passing it.
'To accomplish this, to swerve their star from its course, the globemen made use of a simple physical principle. You know that a round, spinning body, moving across or through any medium, changes its direction if the rate of its spinning is changed. A ball that rolls across a smooth table without spinning at all will move in a straight line. But if the ball spins as it rolls it will move in a curved line, the amount and direction of curve depending upon the amount and direction of spin. Now their sun, which had rotated at the same rate for ages, had rolled through the ether for ages on the same great course, never swerving. And so, they reasoned, if their sun's rate of spin or rotation could be increased a little it would curve aside a little from its accustomed course.
'The problem, then, was to increase their sun's rate of spin, and to accomplish this they gathered all their science. A mighty tower was erected over their city, on whose great top-platform were placed machines which could generate an etheric ray or vibration of inconceivable power, a ray which could be directed at will through the great telescopelike projector which they had provided for it.
'This done, they waited until the moment calculated by their astronomers, then aimed the great projector- tube at the edge of their sun that was rotating away from them, and turned on the ray. This was the crucial point of their scheme, for now they were risking their very universe. It was necessary for them to increase their sun's rate of spin just enough to make it swerve aside, but if the rate of spin were increased just a little too much it would mean disaster, since when a sun spins too fast it breaks up like a great flywheel, splits into a double star. It is that process, the process of fission, which has formed the countless double stars and bursted suns in the heavens around us, since each was only a single star or sun which broke up because of its too-great speed of rotation, or spin. And the globe-men knew that it would require but very little increase in their own sun's rate of spin to make it, too, split asunder. So they watched with infinite care while their brilliant ray stabbed up toward the sun's edge, and when, under the terrific power of that pushing ray, the star began to spin faster, they at once turned off the ray, which was used for a short time only. But it had been effective; for now, as their sun spun faster, it began to swerve a little from its usual course, and they knew that now it would crash into the other approaching sun instead of passing it. So their end was achieved, and so they began their preparations for their great migration out to Alto's outermost planets, a migration which would take place just before the collision. And then-we came.
'We came, and now we have discovered that for which we came, the reason for Alto's change in course. For it was the science and will of the globe-men that turned their sun aside, that threatens now the annihilation of the Eight Worlds. Doom presses upon them, and to escape that doom they are destroying our sun, our planets, our very universe!'
IV
I do not remember that any of us spoke, when Sarto Sen's voice had ceased. And yet, stunned as we were by the thing he had told us, our knowledge was in some ways a relief. We had discovered, at least, what had swerved Alto from its course, and if science and intelligence alone could cause the sun to veer from its path, science and intelligence might steer it back into that path.
When I said as much to Sarto Sen his face lit up. 'You are right, Jan Tor!' he exclaimed. 'There's a chance! And even as Mur Dak predicted, that chance depends on us. For if we can escape from here and get back to the Eight Worlds, we can come back with a greater force and crush these globe-men, and use their own force-projector to swerve their sun out of its present path.'
'But why go back to the Eight Worlds?' objected Hal Kur. 'Why not get up to that platform, if we escape, and use the projector ourselves?'
Sarto Sen shook his head. 'It's impossible,' he told the big engineer. 'If we escape from here at all it will be by night, for by day the rooms and corridors outside are thronged with globe-men. And by night we could do nothing, for Alto, the sun itself, would not then be in the sky. Nor could we wait for its rising, there on the platform, since our escape would soon be discovered, and we should be attacked there. Our only chance is to get out of here by night, make our way up to the platform, and make a dash for our ship. If we can do that we can flash back to our own universe and get the help we need to crush these globe-people.'
'But when shall we make the attempt?' I asked, and my heart leaped at Sarto Sen's answer. 'Tonight! The sooner we get out the better. A few hours after dark we'll try it.' He went on, then, to unfold his plan for escape, and we listened intently, while big Hal Kur's eyes gleamed at the prospect of action. Our plan was simple enough, and likely enough to fail, we knew, but it was our only chance. What course we would follow after getting free of our cell we did not even discuss. There was nothing for it but to make our break and trust to luck to bring us through the thousand obstacles that lay between us and the tower-platform which held our ship.
The remaining hours of that day were the longest I have ever experienced. The slanting shafts of light from the loopholes seemed to move across the room with infinite slowness, while we awaited impatiently the coming of night. At last the light-bars darkened, disappeared, as the dying crimson sun sank beyond the rim of the world outside. Darkness had descended on that world, now, and here and there among the buildings, and streets of the weird city outside flared points of red light. Still we waited, until the vague, half-heard sounds of soft movement and thrumming speech outside had lessened, ceased, until at last the only sound to be heard was an occastional shuffling movement of the guard outside the door.
Sarto Sen rose, making to us a signal of readiness, and then threw himself flat on the floor of the room's center. At the farther side of the cell lay Hal Kur and Nar Lon, as though sleeping, with a thick roll of garments between them which resembled another sleeping figure. These preparations made, I stepped to the door and stationed myself directly inside it, to one side, my heart pounding now as the moment for action approached.
All was ready, and seeing this, Sarto Sen began his part. Lying there on the floor he gave utterance to a low, deep groan. There was silence for a moment, and then another low moan arose from him, and now I heard a shuffling movement outside the door as the guard there approached to listen. Again Sarto Sen groaned, terribly, and after a moment's pause there came a rattling of bolts as the guard slid them aside. I flattened myself back against the wall, and in a second the door opened.
Even in the darkness, glancing sidewise, I could make out the round, globular form of the guard, his eyes peering into our cell and his fire-disk held out in cautious readiness. A moment he paused, peering at the three dim figures lying across the room; then, as if satisfied, turned his eyes back upon Sarto Sen, at the same moment taking a step inside the door. And with a single bound I was upon him.
Of all the fights in my career I place that struggle there in the darkness with our globe-man guard as the most horrible. I had leaped with the object of wresting the deadly fire-disk from him before he could make use of it, and fortunately the force of my spring had knocked it from his grasp. His short, thin arms clutched at me with surprising power, though, while the insect-like lower limbs grasped my own and pulled me instantly to the floor. A moment I rolled there in mad combat, striving to gain a hold on my opponent's smooth, round body, and then a thing happened the memory of which sickens me even now. For as my hands clutched for a hold on the sleek, cold, globular body, that body suddenly collapsed beneath my weight, breaking like a skinful of water and spurting out a mass of semi-liquid jellylike substance which flowed across the floor in a shining, malodorous mass. Fleshlike as they were in appearance, these creatures were but globular shells of ooze.
Sick to my very soul I rose to my feet, looking wildly at the others, who had rushed to aid me. There had been no cry from our guard during that moment of combat and the silence around us was unchanged. Sarto Sen was already at the door, peering down the corridor, and in a moment we were out of the cell and making our way stealthily down the long hall. As we left the cell, though, my foot struck against something, and reaching down I picked up the little fire-disk of our guard. As we crept down the long corridor I clutched it tightly in my hand.
The long hall, dimly lit by a few red flares set in its walls, seemed quite deserted. Ahead, though, shone a square of brighter light, and we knew this to be the spot where the corridor crossed the anteroom of the guards. Nearer we crept toward it, even more stealthily, until at last we crouched at the edge of the open doorway, staring
