Numberless, indeed, were the hordes of those Neptunians, their masses swarming about us in great crowds of disk-bodied, pale-green monsters, busy upon the clanking, beating, hissing mechanisms around them, busy in providing the heat and food and water of their strange world. It seemed impossible, almost, that so many countless millions of them could thus have crowded together on Triton's surface. All wore the strange armor or dress of flexible metal around their disk-bodies, some carrying ray-tubes slung in that armor and others various tools or instruments. Here and there we saw one with the same crimson-circle insignia as our leader's upon his metal armor, and it was apparent from the silent deference shown these circle-marked Neptunians that they were officials of some kind. As we marched on behind our leader, our guards close about us, we saw that, despite our strange appearance to them, the Neptunians paid no great attention to us--so busy were they. We saw, too, that here on Triton's sunward side there were no shelf-like sleep-compartments at all, all such being upon the dark side. In silent awe and wonder Marlin and I moved on through the thronging compartments, countless Neptunians crowding busily all about us, and countless cylinders throbbing through the air above, with the vast roof far above them. Then I sensed that we were approaching our destination. For before us now, as we crossed a last compartment, there lay that twilight band of dusk which marked the division of Triton's dark and sunlit sides, and as we passed out of the pale, dim light of the sunlit side into the twilight of that band, we saw that before us lay a compartment wall that was curving instead of straight, the wall of the great single circular compartment we had noticed from above. The compartment that lay between us and that wall was empty save for a file of Neptunian guards who stood motionless along the curving wall with their force-ray tubes ready in their grasp. As our leader reached them he halted, spoke with them for a moment in staccato speech, and then as their snapping voices ceased the guards stood aside to right and left and permitted us to pass through the low, broad door in that curving wall. Through it we went, our circle-marked leader first and then Marlin and I, our four guards still close about us, and then as we halted inside that door, we two were gazing with a deepened awe and wonder about us.