The point is, we had lived with the vague knowledge of the Atomic Curtain all our lives, and the whole thing was too fantastic either to understand or to matter to the average run of us. It was like the toadstools of our forests—they were quite poisonous, but so long as we did not have to touch them, we ignored them. I remember a passage from one of those books I finally unearthed at Oxford—a curious thing, possibly a fake, and yet dressed out in the most pompous language, purporting to be the considered opinion of some distinguished man of science at what apparently was a famous university, a place called Harvard, and confirming a suspicion that life was possible on Mars. Yet nowhere in the American histories of that year, nor in any of the contemporary American publications, could I find any evidence of general alarm about it. So there was life on Mars. Presumably no one bought extra ammunition for his gun, nor hoarded food, nor drank himself to death, nor went to church more arduously because of any such remote impracticality. Who was going to Mars? And who—to bring this analogy down into our times—except the pilots of the International Patrol meant to venture toward the well-defined and fortunately distant zones contaminated by the Atomic Curtain?
Yet I must admit that something of O'Hara's fascination for it crept contagiously into the letters that came back to me from those far-flung and frigid bases out of which he flew for the Patrol. There was news in them, too, although I did not always recognize it.
The first of these letters reached me within a month after I squeaked onto the staff of the Observer. O'Hara had by then completed his basic indoctrination with the International Patrol and was serving his initial hitch in the least desirable of the Patrol's assignments, with nothing behind him but the Antarctic seas and the vast polar cap, not a city worth the name closer than Hobart, in Tasmania, completely across the Antarctic Circle from his base.
It must have been dull work, flying from the Falkland Islands to South Shetland, deafened by roaring jets and blinded by the frightful gales that swirled around Cape Horn, and for variety he had the constant ticking of his scintillometer telling him how closely he was approaching the southern boundary of the Atomic Curtain, quite narrow there, encompassing the Cape itself and the wild seas immediately beyond.
Dull work? I remember O'Hara's first letter: "The black sky meets the blacker water upon a horizon even more intensely black, a horizon that is a ribbon of mourning constantly below the level of my eyesight, as if these were dead seas and dead heavens. But the coloration is deceptive, for they are not dead. The howling violence that must have been the planet's birthing wail still echoes here, the raging winds that must have screeched throughout infinity when Earth ripped loose from the Sun—and beyond, ten miles ahead of me, perhaps, the Wall of Death invisibly stands shimmering.
"One second's miscalculation at the speed I fly and I'd be into it. Freezing one instant, roasted to the bone the next. How thick is that wall? The guess that we credit oftenest is twelve miles. A scant twelve miles of radioactivity, and I could fly that far in the time it would take you to snap shut the fingers of your hand—perhaps my craft on its momentum would plunge through. I think it would. I think I could aim it for the southern tip of South America, and by the time that you could walk across the editorial room there at the Observer in London, I would have smashed across the Atomic Curtain and landed on that coast that once was Patagonia. Isn't that a challenge? A terrific challenge, to be the first within two hundred and seventy years to reach the two lost continents! But it has the undeniable drawback that I would be dead, and so could not gloat like stout Balboa on a peak in Darien.
"I saw the Curtain doing its merry routine one day last week. I was flying quite low, not a hundred feet above the surface of the sea, making a customary check upon the water's radioactivity. We do this every flight, to check upon the contamination of the water, which usually is quite constant, flowing out from below the Curtain a distance of fifty miles but decreasing in activity with an almost mathematical precision. Yet when there is a really powerful gale blowing southward or westward from the Curtain, from the tip of what once was called Chile or Argentina, both now encompassed by the Curtain, the surface currents sometimes are reversed from the Cape—the fabled Cape Horn of early mariners—and the contamination flows much further toward the Antarctic before it diffuses.
"Of course our base in the Falklands is mildly contaminated, all these fringe areas are, and all of us have a touch of the atomic sickness, just as those living in the tropics have malaria. You know what it's like—nausea sometimes, and always diarrhea, a tendency toward bleeding gums and conjunctivitis and—well, yes, dammit, falling hair, baldness. I shall resemble the egg of the great auk in another ten years of this. Sounds terrible. Actually, though, these are only tendencies, for we do not expose ourselves beyond the lowest background counts upon our scintillometers. We're taking no chances—this is a Patrol, not a combat unit, for there's nothing to combat. Nothing, nothing but that invisible curtain, at a fixed latitude and a fixed longitude for every foot of its tens of thousands of miles, with only the variances of the surface contamination that I mentioned. Which brings me back to what I meant to tell you.
"I was patrolling one hundred feet above the ocean's surface when I saw ahead of me, not quite to that black ribbon of a horizon I have described, a strange dark object, apparently floating on the sea. Immediately I changed course toward it, but when I had reached the absolute limit of radioactivity that we are permitted the dark object was still ten or more miles ahead of me.
"It must have been, at that instant, extremely close to the Curtain itself. If it was not within it! Yet it was plowing toward me through heavy seas, the first moving object I had ever seen in this sector.