They had been wandering for several days and nights--covered with ooze and slime now, torn and bleeding with stumbling, falling on the rocks. How far they had gone they had no idea; traveling, they calculated, generally eastward. There were a few island mountain-tops, they thought, between here and the great Marshall Rise. It was soon not a journey, but a desperate wandering, with mountain streams to avoid; cliffs to descend, to climb again when the valley laboriously had been crossed; mud, sometimes like quicksand, upon which they crawled. Dank, hot days, often with blinding sunlight; dank, cold nights with the black noisome fog settling around them. Arturo was burning with fever now. They were both gaunt, haggard. “Tad, look! Look up there!” It seemed about sunset, though of that they could never be sure. The sun was gone down behind some distant upstanding rim. There was sunlight on the white clouds of the heights, but in the abyss the deep purple shadows of night had long since gathered. There was sunlight still on the distant domes; a waterfall, halfway down, gleamed like a white veil; but the crags and tumbled land beneath it were grim and dark. Tad and Arturo stood gazing up into the fading daylight. A white-winged plane was slowly circling, up near the Zero-level and five miles or so north of them. It came nearer, like a great white bird, soaring. The sunlight up there edged it with yellow and red. A long white banner streamed from it, waving with its forward motion. Silent, soaring white bird, it circled, and went slowly back northward. The mists of the Lowlands were not yet gathered. The scene was clear to Tad and Arturo as they stood down on the dark floor. Breathless, awe-struck; a silent drama was beginning up there. The plane with the white banner was alone. But far above it, off in the northern distance, a speck showed close under the white clouds, several thousand feet above the Zero-level. A speck; another earth plane, taking no part--like Arturo and Tad, just watching. For a time the white banner of truce circled alone. And then, as the night gathered and deepened, another shape appeared, wingless, long and narrow, and gray-white. The sunlight soon was gone up there, the yellow glow merged to the silver of the moon--a full moon, still below the eastern horizon of the Lowlands. But it caught and painted with its silver the fluttering white banner; the narrow, wingless aëro glowed in it, unreal as a ghost. The two white shapes neared each other. The wingless aëro stopped dead, poised. The white banner, fluttering its peace offering, its message of humanity, approached slowly. Tad and Arturo stood gazing, breathless. Then suddenly stricken. Why, what was this! What--What--They stared, unbelieving, clutching each other. Drama, tragedy, so silent up there in the moonlight over the darkly spreading wastes of the abyss! They stared. And presently when it was over, they started forward, running.