"The giant ray!" Whitely was shouting, as we thundered forward. "We've still more than a thousand fliers left, and if we can get now to that great sun-ray----!" "Hold steady after them!" Marlin cried. "We've fought our way this far, and we've got now to get to that ray and halt it!" Now out over Neptune's surface, out through its mists and outer atmosphere again, the cylinders ahead were roaring at utmost speed, almost leaping in a confused and disorganized mass, the remnants of that mighty fleet that had come out to meet us outside Neptune, toward their moon-world of Triton, whose disk gleamed bright ahead. A thrill of pride even in our wild excitement shot through me as we thundered on in pursuit of those fleeing cylinders. For whatever else that day might hold for us, whether or not we were able to halt that giant ray on Triton's sunward side that was reaching out to the sun and turning it ever faster, we men of Earth had at least proved our fighting ability to the solar system for all time, had come out to the solar system's edge and had shattered there the mighty armada of the Neptunians' ancient and mighty race! And now as we flashed on in swift pursuit of the fleeing survivors of that armada toward Triton, confidence and hope were strengthening in us each moment, for with the Neptunians' great fleet shattered what could hold us back from the shattering and halting of the giant sun-ray and its mechanism? On--on--and now we were rushing after the fleeing cylinders out of Neptune's atmosphere and into the airless void again, with Triton growing each moment more bright and big as giant Neptune fell behind us. Across the gulf from Neptune to its moon we sped, after those cylinders, with utmost acceleration and speed, and swiftly we drew closer to the Neptunians flying before us, and swiftly too drew closer to the gleaming sphere of Triton. And as it grew larger before us, as we pursued the cylinders in toward it, we all cried out as we followed with our eyes at the sunward side of it the giant pale beam, hardly visible, of the colossal force-ray acting on the sun, that mighty ray that was turning the sun ever faster to the doom of the solar system! We could make out that gigantic beam, leaping out into space toward the distant fire-disk of the sun, and could make out also in that moment a great number of great humped dark shapes gathered on Triton's roof around the great pit of the sun-ray. As our eyes shifted to Triton's other edge we could discern the other giant force-ray, which reached out toward the distant star in Sagittarius and by bracing Triton with its pressure kept the moon-world from being hurled out into space by the sun-ray's pressure. Around this other ray's pit, too, were a few of the strange great humped or domed dark shapes, but in that moment we gave them small attention, for the cylinders that had been fleeing from before us straight toward the great sun-ray's giant beam, had