O'Hara was cruising at two thousand miles an hour. His fuel gauges indicated that he might keep going for three thousand miles, depending on his altitude. It was necessary, he knew, to get above forty thousand feet and to stay there for his best distance, and he had to have distance toward the south—for the storms of December would have driven snow deep along the lost continent of North America. He was not equipped for any lengthy existence in snow. His craft had the Patrol's usual paraphernalia—an inflatable boat, a signal pistol, a .38 automatic with six clips of ammunition, emergency water supply, emergency rations, the items considered indispensable when a rescue team could be expected to begin search soon after he failed to report to his base at Wrangell Island. But now, south of the Curtain, no rescue team was coming. None could get through. In consequence, his life depended on getting below the wasteland of the Arctic.
These things, O'Hara said, ticked automatically through his mind in those first few minutes after he realized that he had got through the Curtain—these, and the overwhelming importance of the fact itself, that the Curtain could be pierced. He had, of course, no idea how the thing had been achieved. It had happened while he was unconscious, but as he reasoned it, his craft must have spun from north to south and then rammed through. Nor had he any data on the milliroentgen count of the Curtain itself—he had no idea of the contamination to which he had been exposed. He realized that at this moment he should have been a charred mass of carbon, like the bodies of those men on Coronation Island, in the Antarctic, after their vessel of logs had drifted into the Curtain.
But the indisputable fact remained that he was not carbonized. He could only accept it and take whatever precautions seemed most likely to keep him alive, which now, at this moment, seemed to call for flying south.
Within minutes he was crossing a coastline, and following the bed of a frozen river that pointed roughly south. Far toward his right—the west—the saw-toothed stubs of mountains poked their glittering ice-sheathed peaks up from the continent, and O'Hara was remembering the maps he'd studied as a boy. That way, the west, must be Alaska. Again he checked his position in latitude and longitude, then deciding that the river course below him must be the Mackenzie, reaching down past Great Bear Lake in Canada toward Great Slave Lake. And somewhere distant past the snow-packed tundras toward the east would be the land-locked gulf of Hudson Bay.
"Remember," O'Hara said, "I wrote that time telescopes in the Patrol? It was telescoping for me now—I was back again with old Hendrik Hudson, though thank God not in quite the same kind of boat. I was opening up the West again, seeing the amazing continent, the wonders that I'd seen before only as dotted lines and red-and-blue ink sworls on long-forgotten maps. And in five minutes—the five since I had passed the Curtain—I was exploring more of this tremendous northland than old Hendrik ever dreamed of."
Wonders, yes—but wonders unfortunately very like those of the land mass of Siberia, and so no different from what he'd known before he smashed through the Curtain. O'Hara felt somehow as if the myths of the Lost Continent had let him down. Until he noticed the recording of his scintillometer.
It had dropped only to .305 milliroentgens an hour. That was high—dangerously high according to the flying regulations of the Patrol, yet it had been much higher further north, toward the Curtain. He could only hope that with his progress south the count would gradually decline. Then it occurred to him that radioactive water might be running underneath the ice of the Mackenzie, draining southward from the Curtain, and he swerved hard toward the east, leaving the river bed some hundred miles behind before he made another reading. The milliroentgen count, rather than dropping, had risen to .325 an hour. And simultaneously O'Hara's memory dredged up a curious fact—the Mackenzie flowed toward the north. It could not possibly be contaminated from the Curtain.
O'Hara now turned again toward the west, crossing the Mackenzie and heading for a tremendous region of ice-capped peaks, their vast flanks swathed with the silver sheen of the greatest glaciers he had ever seen—the northern reaches of the Rockies, he concluded, the neckbones of the spinal column of the continent.
In this race westward, his milliroentgen count was sliding steadily, until, above the mountain chain itself, the count seemed stabilized at last at .285. Yet when he pushed beyond, toward the western coast—the Pacific—the count immediately began to jump again. He made the indicated correction in his flight, adhering to the southeast curvature of the mountain chain, and concluding that he had discovered a corridor of lesser contamination, its base upon the Curtain in the north, and its two flanks, on the eastern and western sides of the mountains, strongly radioactive.
He had now been below the Curtain—below, that is, the northern ellipse of the Curtain, for it was known to enclose the Atlantic and Pacific coasts as well—for thirty minutes, boring steadily south despite the zigzag pattern of his exploration, and the character of the terrain was changing, not less mountainous but with some indications of a seasonal variation in the snow pack, for oftener now the bare rock precipices and peaks showed through, and beyond the upraised spine of the Rockies, toward the distant shimmering deep blue of the Pacific, the snow itself had taken on a stippled appearance—immense forests, O'Hara concluded, blanketed but shaping the white countours upon them. And farther still, merging into the rim of the ocean's curve, lay a varying band of dark brown and black and vivid green, presumably a thickly forested shore, completely free of snow. O'Hara made a quick calculation based on his known altitude and an approximation of the distance to the horizon. The result astonished him. The forest belt extended inland for three hundred miles.