An hour we hung above the colossal barrier, fascinated, and then remembered our mission and sped again south.
As we rocketed on, we could see no sign of life below, nothing but the bleak arctic plains with here and there some sparse vegetation.
Again Lantin cried out, and when I looked south, I discerned an odd flicker of light, a seeming hesitating wavering of the air. We sped down toward it, dropping down again to a scant mile above the ground.
Far ahead showed expanses of bright green, and as we drew nearer, I saw that there were small patches of white against the green, oddly regular in shape. As we sped on, these white blotches changed to buildings, and the green to verdant lawns and gardens, in which they were set. Again Lantin stopped the car, while we looked down, puzzled. For in a straight line from east to west, was the boundary, the limit, of the gardens and the buildings. North of that line were the cold, wind-swept plains and stunted, arctic vegetation, while south of the same invisible line, seemingly only a few feet from the bleak tundras, began the luxuriant, tropical gardens, stretching away south as far as the eye could see. And also the elusive flicker of light seemed to begin at the same point, and to be present everywhere south of it. If you have ever seen the flicker of heated air above railway tracks or hot sand, on a warm afternoon, you will understand me. It was like that, an elusive, fleeting wavering in the air, below us.
"I can't understand it," said Lantin, pointing down to the invisible line which separated arctic world from tropic. "Gardens like those, only a few feet away from the cold plain."
"It's beyond me," I told him. "Another thing, Lantin, the car is as cold as ever, even with the heater functioning. Yet down there the country looks tropical."
He shook his head, and starting the car, we sped on south, as cold as we had been above the glacier, while below was a landscape that reminded me of Florida, in my own time. Set in the lawns and gardens, the white buildings became more numerous as we sped on. We could see that they were of varying shapes, some cone-shaped, others cubical, while still others were spherical, like great globes of white stone sunk a little in the earth. The cone-shaped buildings were the most numerous, I saw, though there were many of the other designs. But nowhere was there a building that was cylindrical.
Ever and again our eyes caught that inexplicable flicker in the air below us. We were flying with reduced speed, now, less than a mile above the ground, and beneath us the lawns and gardens had disappeared, giving way to the crowded buildings of a great city. In the broad streets of that city were tiny, moving figures, and many vehicles seemed to flash continually along the wide avenues. But there was no sign of aircraft.
Always the buildings grew larger, and it was plain that we were approaching the city's center. Away ahead of us a great cone began to loom up gigantically, an immense, cone-shaped building that was fully as large as the temple of the Raider, back in the city of the Kanlars. We changed our course, headed down toward the colossal center building. As we drew nearer, we saw that it was smooth and unbroken of side, and at its top it was truncated, flattened, the summit of the cone forming a flat, circular platform a few hundred feet in diameter. We glimpsed this much, and then Lantin sent the car down on a long slant toward the cone's flat summit.