The pelting never ceased, never let up even for a moment. Minute after minute the sand came sweeping down in red fury, tons upon tons of it, in great circular waves from high overhead and in jet velocity flurries close to the ground. In that assault of billions upon billions of spinning particles the brightly colored lichens which covered the Martian plains were uprooted, lifted high in the air, and carried for dozens of miles, flying carpets so small they scarcely could have supported the tiniest of elves. For three hours the sandstorm continued to rage in fury, and then, abruptly, the wind died down, the last flurry subsided, and the colonists got under way again. And just for a change a few of them descended from the tractors and advanced on foot, keeping a little ahead of the swaying vehicles. Dr. Drever, a tall, stooped man with graying temples but surprisingly youthful eyes accelerated his stride a little and fell in with the scarecrow geologist who was walking at Corriston's side. "We can't be far from the ship now," he said. "I wish there was some way I could send Freddy back. If I thought you could spare a tractor and one man to accompany him...." "Freddy will be all right," Corriston said. "You don't know what it means to a kid like Freddy to ride through a sandstorm in the company of grownups. He had to prove something to himself, and I think he's done it." The stillness was almost unnatural now, and Corriston could see that most of the men were becoming uneasy about it. The desert seemed too bright and far too quiet. It was one of those mysterious, brooding silences that are a menace to start with. You think of unsuspected pitfalls, hidden traps. Imagination leaps ahead of reality and leaves an insidious kind of demoralization in its wake. "I'm not surprised that all the animal life on Mars went underground," the scarecrow geologist said, and it seemed a strange thing for him to have mentioned at that moment, when the stillness was so absolute and the thoughts of everyone should have been on the ship, which had to be very near now. "Yes, and what a vicious, horrible kind of animal life it is," Drever said, as if he too welcomed the opportunity to talk irrelevantly, perhaps to relieve his inner tension. "They're a very primitive form of life, really," the geologist said. "They look like large gray snakes, but they're actually more like worms. Worms with sucker disks instead of mouths. When once they've' attached themselves it's almost impossible to dislodge them. You've seen marine worms on Earth often enough, I'm sure. They come in all shapes, sizes and colors, but there are one or two species that look quite a bit like lamprenes in miniature. Lamprenes are usually about three feet in length. But some of the very old ones grow to eight feet or longer. Their natural prey is a small running lizard--the galaka--as you know."