It was early morning now, bright and sunny, and peering down over the car's side to the valley below, I could see no sign of life. In the two days through which we had passed so quickly, it was evident that the guards had given up searching for us and had returned to the city. I wondered how they explained to themselves our sudden disappearance. I slid down into the car's interior, now, and closed the circular door above me. Sinking down on the padded floor with utter weariness, I tried to express to Lantin my thanks for saving my life, since had he acted a fraction of a second later, I should have been struck down by the flashing spears of our pursuers. But Lantin would not hear me, declaring that alone he would have been unable ever to reach the car, and so, conscious that without the other each of us would have perished, we let the matter rest. In a few minutes, Lantin returned to the controls, and swinging the car in a great circle, pointed it south, opening up the power gradually until we were racing down toward the southern horizon with our highest speed. Soon, far ahead, the glistening ice came into view, and in a few minutes after that the green land behind us had dwindled to a speck against the ice, and then vanished. High above the ground, we sped across the endless ice, splitting the air like a meteor. Hour after hour we fled on, across the gleaming fields of whiteness. The cold air had forced us to turn on the heater of the car, and even with it, we were none too warm. Below, from horizon to horizon, billowed the frozen fields, with here and there a white dune or hill to break the monotony of the landscape. Finally, in midafternoon, a thickening line of black showed against the southern horizon. We reduced our speed, and sinking closer to the ground, sped down toward the black line. It seemed to grow as we came nearer, loomed larger and larger, until at last we hung above the black mass, gazing down at it in silent awe. And it was a wall. But what a wall! A gigantic, mountain-high and mountain-thick barrier of solid black metal, extending as far as we could see, from the eastern to the western horizon. A colossal barrier of metal, all of a mile and a half in height, with a thickness at the bottom of nearly a mile and at the top of half that much. A smooth-sided, dully gleaming mass beside which the walls of mighty Babylon would have been toylike, microscopic. And with that wall, the ice stopped. On the northern side of the barrier, the fields of ice stretched away as far as the eye could reach. But on its southern side there was no ice. Grass of dull green, and small trees, gnarled and twisted by the glacier's cold, lay to the wall's south, a vista of rolling, bleak plains that extended down to the southern horizon.