For the first time then I wanted wings--wanted them myself--that I might join this wife I loved in her glorious freedom of the air. And I realized, too, for the first time, how that condition Miela so deplored on Mercury had come to pass. I could understand now very easily how it was that married women were deprived by their husbands of these wings which they themselves were denied by the Creator. Hardly more than ten minutes had passed before I saw the two girls again flying toward me. They alighted a short distance away, and approached me, hand in hand. The girl with Miela, I could see now, was somewhat shorter, even slighter of build, and two or three years younger. Her face held the same delicate, wistful beauty. The two girls strongly resembled one another in feature. The newcomer was dressed in similar fashion to Miela--sandals on her feet, and silken trousers of a silvery white, fastened at the ankles with golden cords. Her wings, as I have said, were blue--a delight light blue that, as I afterward noticed, matched her eyes. Her hair was the color of spun gold; she wore it in two long, thick braids over her shoulders and fastened at the waist and knee. She was, in very truth, the most ethereal human being I had ever beheld. And--next to Miela--the most beautiful. Miela pulled her forward, and she came on, blushing with the sweet shyness of a child. She was winding her silken silver scarf about her breast hastily, as best she could with her free hand. "My sister, Anina--Alan," said Miela simply. The girl stood undecided; then, evidently obeying Miela's swift words of instruction, she stood up on tiptoe, put her arms about my neck, and kissed me full on the lips. Miela laughed gayly. "You must love her very much, Alan. And she--your little sister--will love you, too. She is very sweet." Then her face sobered suddenly. "Tao has returned, Alan. And he has sent messengers to our city. They are appealing to our people to join Tao in his great conquest. They say Tao has here with him, on Mercury, a captive earthman, with wonderful strength of body, who will help in the destruction of his own world!" CHAPTER XIII. THE CAPTIVE EARTH-MAN. As we came out of the valley I had my first view of the Great City. It occupied a huge, mound-shaped circular mountain which rose alone out of the wide plain that spread before me. As far as I could see extended a rich muddy soil partially covered with water. A road led out of the valley, stretching across these wet fields toward the base of the mountain. It was built on an embankment some eight or ten feet high, of the red, metallic ore of the mountains. All along the base of this embankment, with their roots in the water, graceful trees like palms curved upward over the road. The landscape was dotted with these and other tropical trees; the scene was, indeed, essentially tropical.