Even as I cried out thus, our cylinder was rising upward toward the roof with all the power of its throbbing generators, hurtling upward at speed unthinkable toward the great circle of the opening-section! I was aware in that moment of the crowding swarms of cylinders about and beneath us loosing toward us a storm of crossing force-rays that we drove clear of in that instant. I was aware of the Neptunians in the cage-room beside the great opening-section rushing wildly about as we shot upward like the cylindrical projectile of some giant cannon! The next instant I caught the gleam of the transparent roof, of the opening-section just above us, Marlin and I instinctively crouched lower in our seats, and a moment later there was a blinding, stunning shock that seemed to split the universe with its detonation. We were dragged up from our seats with awful force. And then as we straightened up and looked out, we saw that the cylinder had smashed through the great opening-section and was throbbing above Triton's mighty roof! The cylinder's ceiling, above us, was crumpled and bent badly, but in that moment it seemed a miracle that we had lived through that terrible collision. It was only our awful speed that had saved us, driving us through the opening-section's thick metal even as a cyclone will drive fragile straws and twigs unbroken through a board. Now as we looked downward we saw that the swarming pursuing cylinders were massed beneath the crumpled opening-section and that that circle of the opening-section was slowly sliding aside, bent and crumpled as it was, to allow those cylinders to emerge through Triton's roof after us! And up they came, a full hundred of them, racing up after us at utmost speed, up from the great metal roof of Triton, dark and opaque to our eyes from above, and up through its atmosphere close on our track! * * * * * Through the rushing roar of air about us, the throbbing of our generators, I was aware of Marlin shouting something beside me. I was gazing ahead for the moment, as that wild flight and pursuit passed on through Triton's atmosphere. Giant Neptune's cloudy green sphere bulked gigantic in the heavens before us, and far beyond it was the little fire-disk of the sun. Then I turned back to see the hundred pursuing cylinders, getting ever closer behind us. As I started at the sight, I became aware of Marlin shouting beside me, and at the same moment realized the import of his words. I realized that the throbbing of our generators was halting, hesitating, failing! Our great crash out through the roof had broken some part of their mechanism and now they were failing rapidly, and the speed of our cylinder was slowing!