Sweeping north, we saw under us the Caroline rise coming up. We passed through a broad valley of the Caroline Mountains. The verdured island-tops occasionally showed. I did not know it then, but since the discovery of the Gian encampment by the world, the Carolines were deserted by most of their inhabitants--all who could get away had already fled. Beyond the mountains here, the Lowland floor again sank. A broken, desolate plain lay down there, blurred with rising mist. We crossed it; and soon it began rising again to the ridge we now call the Moon Mountains. None rose nearly to the Zero-level. A volcanic region, starkly grim with its inky black shadows, and weird patches of moonlight that sometimes filtered down. It lay strewn like wreckage; here, undoubtedly, some great cataclysm of nature had in by-gone ages convulsed it, leaving the strewn crags and bowlders; pits like black holes, roundly punched by some giant finger; precipitous cliffs; ravines, narrow and deep. But the whole, from this southern approach, was steadily rising. On the top of the ridge, still many thousands of feet below Zero, the Gians were encamped. Porous, honeycombed volcanic mountains these were, like a great oblong sponge, perched here. They contained caves, grottos, passages and tunnels of every size and character--a vast catacomb. It lay, I think, some thirty miles in east and west extent along the top of the ridge; and ten miles north and south. Beyond it, northward, the mountains and the catacombs ended in a descending northward slope a hundred miles over a broken floor to where the Middge at a still lower level, were intrenched. The grottos, as I first saw them, presented a darkly sinister, wholly unearthly scene. They held fifty thousand of the gray Gians. Already it had the appearance of a fantastic underground city. Hundreds of the dark caverns were occupied by men, women and children in crude interior shelters. But work was going on. Small stone houses were being built. Lights were erected. The openings to the upper air--this was all near the surface--were shaded against the periods of daylight. A scene of sputtering lights, grotesque shadows--unearthly. A subterranean stream of fresh water had been found. The Gians seemed well supplied with food. There was a cavern of war equipment. The army was organized--an army of men, drilled and led by the women. There was a broad passage that rose to the outer air in which I saw three other aëros such as the one Rhana was using. * * * * * I slept in a newly-built, small stone house, always closely guarded. Nereid was with two of the Gian women. The encampment slept during the daylight periods. There were guards then, with heavily shaded glasses, at all the many upward passages. In the night, the activity went on. Neither Nereid nor I were able to learn many details. No one would talk to us, except occasionally Rhana. And our pseudo-liberty was always closely watched.