Mathild drew in her breath. Honath thought fast, as much to prevent panic in himself as in the girl. A sharp-edged stone lying nearby provided the answer. He seized it and struck. The outer surface of the egg was leathery rather than brittle; it tore raggedly. Deliberately, Honath bent and put his mouth to the oozing surface. It was excellent. The flavor was decidedly stronger than that of birds' eggs, but he was far too hungry to be squeamish. After a moment's amazement, Alaskon and Mathild attacked the other two ovoids with a will. It was the first really satisfying meal they had had in Hell. When they finally moved away from the devastated nest, Honath felt better than he had since the day he was arrested. As they moved on down the gorge, they began again to hear the roar of water, though the stream looked as placid as ever. Here, too, they saw the first sign of active life in the valley: a flight of giant dragonflies skimming over the water. The insects took fright as soon as Honath showed himself, but quickly came back, their nearly non-existent brains already convinced that there had always been men in the valley. The roar got louder very rapidly. When the three rounded the long, gentle turn which had cut off their view from the exit, the source of the roar came into view. It was a sheet of falling water as tall as the depth of the gorge itself, which came arcing out from between two pillars of basalt and fell to a roiling, frothing pool. "This is as far as we go!" Alaskon said, shouting to make himself heard over the tumult. "We'll never be able to get up these walls!" Stunned, Honath looked from side to side. What Alaskon had said was all too obviously true. The gorge evidently had begun life as a layer of soft, partly soluble stone in the cliffs, tilted upright by some volcanic upheaval, and then worn completely away by the rushing stream. Both cliff faces were of the harder rock, and were sheer and as smooth as if they had been polished by hand. Here and there a network of tough vines had begun to climb them, but nowhere did such a network even come close to reaching the top. Honath turned and looked once more at the great arc of water and spray. If there were only some way to prevent their being forced to retrace their steps-- Abruptly, over the riot of the falls, there was a piercing, hissing shriek. Echoes picked it up and sounded it again and again, all the way up the battlements of the cliffs. Honath sprang straight up in the air and came down trembling, facing away from the pool. At first he could see nothing. Then, down at the open end of the turn, there was a huge flurry of motion. A second later, a two-legged, blue-green reptile half as tall as the gorge itself came around the turn in a single bound and lunged violently into the far wall of the valley. It stopped as if momentarily stunned, and the great grinning head turned toward them a face of sinister and furious idiocy. [Illustration] [2]