Yet on and on we leapt, and shouted now as we saw the cubes ahead shooting out from the passageway into open space beyond. A moment more and we were on their tracks, were flashing out too from the encircling crimson walls of glowing death, that vanished suddenly from about us as we entered into a vast region of open space, the immense open space that lay at the giant comet's heart! Far, far away from us there stretched the walls of the gigantic coma that encompassed this open space, above and below, enclosing all that space within their deadly electrical sea. This, though, we had expected and it was not this that held our attention in that stunning moment. It was the comet's nucleus, hanging at the center of that space. For that nucleus was a mass of smoothly revolving worlds! Worlds! Worlds there at the comet's heart, worlds that were disk-shaped instead of spherical, a dozen or more of which revolved in a great ring about a single world that was larger than any of the others, and that hung motionless! Over those revolving worlds, down toward that central disk-world the cube-ships ahead of us were fleeing, and as we shot down after them I saw that it and the rim of other disks, though not illuminated by the dusky crimson glow of the encompassing comet, were bathed in light, pure white light that seemed to emanate from themselves! And as we rushed down toward the surface of that central world I glimpsed upon it smooth dark ways and streets, on each side of which were what seemed great, smooth-sided shallow pits; glimpsed multitudes of dark, shapeless figures that moved to and fro along those streets and ways, tending great mechanisms set up in masses here and there along them; glimpsed a single great circular plaza or smooth-floored clearing set amid those streets and pits and massed mechanisms, at the center of which loomed a great, truncated dark pyramid upon whose flat summit rested some big disk-shaped mechanism. Then in that same flashing glimpse I saw that which drove all else from my mind, saw from the surface of all this mighty world a tremendous swarm of great cube-ships that was driving up toward the ships we pursued, and toward ourselves! "Cube-ships!" Gor Han was crying. "Cube-ships in thousands, and they're attacking us!" "Back!" I cried. "Back up and outward! We have no chance against these thousands!"