And then, as I started off vigorously, she added plaintively from behind me: "If—if you will go slow, my husband, or will wait for me."

I altered my pace to suit hers. I had quite recovered my breath now, and for the moment felt that I could carry her much faster than she could walk. I did gather her into my arms once, and ran forward briskly, while she laughed and struggled with me to be put down. She seemed no more than a little child in my arms; but, as before, the heavy air so oppressed me that in a few moments I was glad enough to set her again upon her feet.

The valley broadened steadily as we advanced. For several miles the look of the ground remained unchanged. I wondered what curious sort of metal this might be—so like copper in appearance. I doubted if it were copper, since even in this hot, moist air it seemed to have no property of oxidation.

I asked Miela about it, and she gave me its Mercutian name at once; but of course that helped me not a bit. She added that outcroppings of it, almost in the pure state, like the great deposits of native copper I had seen on earth, occurred in many parts of Mercury.

I remembered then Bob Trevor's mention of it as the metal of the apparatus used by the invaders of Wyoming.

We went on three or four miles without encountering a single sign of life. No insects stirred underfoot; no birds flew overhead. We might have been—by the look of it—alone on a dead planet.

"Is none of your mountain country inhabited, Miela?" I asked.

She shook her head.

"Only on the plains do people live. There is very little of good land in the Light Country, and so many people. That it is which has caused much trouble in the past. It is for that, many times, the Twilight People have made war upon us."

I found myself constantly able to breathe more easily. Our progress down the valley seemed now irritatingly slow, for I felt I could walk or run three times faster than Miela. Finally I suggested to her that she fly, keeping near me; and that I would make the best speed forward I could. She stared at me quizzically. Then, seeing I was quite sincere, she flung her little arms up about my neck and pulled me down to kiss her.