They climbed out on a slanting rock outcropping and he stared around. "This gas must be almost pure oxygen," he said, his voice ringing hollowly. He looked around at the vaulted roof and irregular walls, noticing that his breathing, while not painful, was somewhat labored. Then suddenly the girl laughed wildly and did a few steps of a strange sinuous dance. "What's the matter?" he asked anxiously. She threw herself into his arms with limp abandon and squinted up into his face as though having difficulty focusing her eyes. He believed he understood, and besides he was beginning to cough. She was giggling as he pushed her head under the water, but he had to force himself to overcome his instinctive Earth reactions before he could take that first breath of liquid. After a few minutes Xintel gave him a shamefaced smile. "Did I make a fool of myself?" she asked. "Of course not," he replied gallantly but with a trace of absentmindedness. Slowly they let themselves drift down into the city, with Barry's mind working furiously. He had remained out of water several minutes. He though of the colony, and--until Xintel touched his arm--of Dorothy. The experience gave a new purpose to his oddly timeless life. After that during each waking period he swam up to the cavern roof. Each time, as well as he could judge, he was able to remain out of water a little longer. At first Xintel scolded him bitterly, as from time immemorial wives have scolded husbands for their own good. Upon the Venusians breathing gaseous oxygen had the same effects as alcohol addiction on Earth. She told him horrible stories of people who had drunkenly wandered into the Outside and fallen afoul of norus or torvaks. She pointed out an oxygen addict who moved jerkily and seemed half insane. Once she even resorted to the ancient feminine weapon of contending amid loud sobs that he no longer loved her or he would instantly cease his debauchery. But Barry persisted, and after following him and seeing for herself that he did not become intoxicated she finally accepted his habit, along with his periods of silent thoughtfulness, as an inborn peculiarity of her alien mate. VI Gradually, so gradually he could not determine when it started, he began to hear a new word whispered around the city. "_Demon!_" "The demons are not all dead!" "The demons have returned!" "The demons gather to attack us!" "Only Komso can save us from the demons!" "Is he--?" "Perhaps her father, Soren Who Died Accursed, was a--" "Have they found--?" "Will the demons--?" A shuddering uneasiness spread insidiously among the people, and their attitude changed. Venusian men watched the Earthman with hostile speculation in their eyes and hands close to weapon hilts. Women moved aside as he approached, dragging their children with them. Although not a single individual mentioned demons to Barry's face he knew he was somehow concerned.