"You came from up there?" demanded Ylda. "Then you are of the race of the true gods, Zo Aldan and Ung Roth?" The Aarthman shook his head. "No, we are mortals. I have read your mind and learned about your gods. Perhaps your gods, too, were mortals from another world who landed here safely on Osar." Hardan's ears tingled at such heresy. And yet he was forced to admit what the little man said was logical. He knew that many of the wisest Wetlanders did not believe in Thog Molog and the devil-things, nor did he suppose the Drylanders believed in the power of Zo Aldan and Ung Roth. It was true the two gods had come from the outer moons in a strange metallic ship. "Why then," he asked, "did you not conquer the Drylands? Was it not for that you came to Osar?" Kern Rensom tugged at his scrubby beard. "We were too few at first. And when there were a thousand of us we tried to use the weapons and tools we had sealed away, but we had forgotten. All the juice that powered them had seeped away. Nor could we repair them." "But you have books," insisted Hardan. "They would tell you." The little man was shamefaced. "While we waited; hunting, building our city, and tilling our fields, we forgot how to read. For many centuries we have lived on a level but little above that of the Drylanders." Hardan swore with amazement. Despite their wonderful mental power these Aarthmen were little better than ignorant savages. Perhaps if he could bring a few wise men from the Wetlands to this valley and have them work with the Aarthmen they could reconstruct that forgotten language and learn to build ships that flew in the air. With great ships like theirs the journey from Wetland to Wetland would be simple and all Osar would be opened to them. No longer would they be forced to haul sleeping tanks of water by slow wagons across the dry-grassed plains.... * * * * * The trail wound aimlessly, it seemed to Hardan, down into the vast circular abyss of the crater. And after a time, as they neared the lower slopes, he saw the Aarthman scratch his shaggy brown head in apelike fashion, and stop. "You've lost your way," he told Kern. Kern Rensom nodded. "I escaped from a small band of Roons, the Drylanders who dwell on the slopes above our craters, two days ago. I was hunting on the northern side and was forced to circle southward to where you found me." "But if we continue downward we must come to your city," Hardan said, puzzled. "Why do you hesitate?" "All Smeth Valley is surrounded by a high wall, Hardan, built by my people. But on the southern inner slope for more than a mile an ancient, higher wall was there. A wall circling down to the lake. "Since we came to Smeth Valley only a few men have ventured beyond that wall, and of them all only one returned--a madman!"