You will be interested to know what the light was. Small, self-luminous organisms were gathered from the open water and placed—hundreds of them—in the translucent pods. Similar organisms to these form the familiar “phosphorescence” of the tropical waters of your Earth. But these were much larger—more the size of your glow-worms. We swam slowly along. A few Marinoids were in the streets, passing us as they went to their occupations. From a window, or the bottom of a doorway, a naked child would peer at us with big curious eyes. In a horizontal street of more pretentious houses, where the tunnel deepened to two stories, a woman sat in the corner of a little balcony, nursing her infant. Beside her, two older children played a game with shining opalescent shells. We turned upward into a vertical street. You would call it a huge elevator shaft. Its lights were fastened to the sides of buildings. Here the houses were one on top of the other—a single low story only, and very long horizontally. Nona did not like them; one was vacant here and Caan suggested it but she refused it decisively. I had no opinion to offer; they all looked all right to me. We swam upward and soon reached the central cube of open space. Here was the ruler’s palace. Open water surrounded it on all four sides, and on top. The main stalks of the building grew above it with graceful hovering fronds of green—fronds whose smallest pods were luminous like a hundred tiny Chinese lanterns—under which, on the roof of the building, was a garden. There were small plants growing there, gleaming white shells laid out in designs, a bed of black ooze with brilliant red things like flowers growing in it. A row of small illuminated pods formed a parapet to the roof top. * * * * * The main building was not as large as the term “palace” sounds—it was not over fifty feet in its greatest dimension. It had both vertical and horizontal balconies, and a broad horizontal doorway near the top—a doorway built of shimmering iridescent shells plastered together with mud and a gluey substance which was made from one of the Marinoid plants. And on a tiny platform by the doorway lay the shell sleigh with its marine animal and its driver in waiting—the sleigh in which I had first seen the King. It was to us a magnificent dwelling, this palace. Nona and I floated before it, gazing with awe. But my heart sank, for I knew that now Nona had seen it, we should have much more difficulty in selecting our own humble little home. It was indeed, almost the time of sleep before Nona made her choice. She selected a two-story house, at the intersection of a horizontal with a vertical street. It had one room upstairs, and two downstairs—small rooms, you would call them, no more than fifteen feet cube.