"Ages passed over them while they lived thus in their world's depths, but still the nebula contracted, closed in upon them, in that vast, remorseless cycle that is nature's law throughout the universe. Closer and closer crept its fires toward the metal-sheathed world of the nebula people, until at last they saw that soon those fires would envelop their world and annihilate it, unless they were turned back in some way. So for a time they bent all their energies toward the problem of turning back the nebula's contracting fires, and at last found a way to do so, one which would take all their strength and science to carry out. "In the surface of their metal-covered world they sank a vast, metal-walled pit, and in that pit set massed machines capable of generating an atomic ray of terrific power. From each of the generating-machines led a connection carrying the power produced by it, all these connections combining into the thick cable we saw which leads into the great cylinder-apparatus, generating inside it the mighty ray that stabs up toward the nebula, and into which we crashed. Now the great world here at the nebula's heart is already spinning, revolving, and the purpose of the nebula people was to use the great ray as a connection between their spinning world and the encircling nebula, to set the nebula to spinning also by this means, the ray being equal to a solid connection between the two. And their plan proved a sound one, for after the great ray had been put into operation the vast encircling nebula began to move slowly, to revolve, faster and faster as its turning accelerated under the constant impetus of the great ray. "When the nebula should reach a certain speed of whirl, the nebula-creatures knew, when it should reach the critical point of its spin, it would be whirling so fast that it would not longer be able to hold its mighty mass together, and it would break up, disintegrate, its fiery mass flying off through the Galaxy in all directions. This would remove all danger from the nebula people, who could then live on without fear in their cavern-honeycombed world, using artificial light and heat. They knew, however, that once started the whirling of the nebula must be kept up until it had reached its critical point and had broken up, since if the whirling were slackened before then, the great ray turned off, the vast, ponderously turning nebula would collapse with the removal of the ray, its collapsing fires annihilating the nebula world inside it. For this reason the great machines in the pit that generated the power for the ray were made completely automatic and certain in operation, needing only a handful of the nebula-creatures to attend them.