 What causes the shaking of the mountain?
WHEN THE MOUNTAIN SHOOK By Robert Abernathy Illustrated by Kelly Freas [Transcriber Note: This etext was produced from IF Worlds of Science Fiction March 1954. While she waited he spun a dream, attaching it to the crags that loomed over the pass, and to the frozen ground underfoot. Now they were descending the steeper face of the sierra, and the way led over bottomless crevasses, sheer drops and sheer ascents, sheets of traitorous glare ice. The light shone watery and dim from beneath the hoary back of the glacier, and as they came nearer they saw why: the cave entrance was sealed by a sheet of ice, a frozen waterfall that fell motionless from the rocks above. Var eyed the ice-curtain closely to make sure that it was real, not dream-stuff; then he struck it boldly with his fist. Var saw with some surprise that all the walls were sheathed in ice—warm to the touch, bound fast against melting by the Watcher's will. Behind them began a tinkling of falling water, thawed from the glacial ridges above to descend sheet-wise over the cave mouth, freezing as it fell into lengthening icicles. Hot food and drink were before them almost at once. They ruled the Earth for four generations, and the Earth was too little for them. "Because of them we must build with dreams instead of iron, and our only fire is that of the Sun, and even now, two thousand years later, the Earth is still slowly recovering from the pangs and poison of that age. Only the angry light of fires relieved the city's darkness—that, and the blue-white lightning flashes that silhouetted the naked skeletons of buildings and were followed by thunder and a shaking of the earth. All round, from the lowest and most poisonous levels of the shattered city, the slaves swarmed up in their millions. From the center, over the citadel, an immense white globe soared upward, rising swiftly without sound. These raised a black mountain from the Earth's heart, and in hollows within it cast themselves into deathless sleep, their deathless and lifeless sentinels round them, to wait till someone dare arouse them, or until their chosen time—no one knows surely. "I have told you the story you know, and have shown you a glimpse of the old time, because I must make sure that you do not approach the mountain in ignorance. Our world is unwise and sometimes evil, full of arrogance, folly, and passion that are in the nature of man.
 Machines
 The awakening of the Ryzgas  Machines  Earthquakes and tremors  Dreams spun by the Ryzgas