The silver airship cut swiftly through the hot thin air. The noonday sun blazed down upon it and the desert world below. All about was the solemn silence of death. No living thing appeared either in the air or on the drab, gray earth. Only the aircraft itself displayed any signs of life. The sky, blue as indigo, held not the shadow of a cloud, and on the horizon the mountains notched into it like the teeth of a giant saw. The airship finally came to a hovering stop, then dropped rapidly toward t