It was a fixation. What he had said was true enough--for later on I did get around to those long-forgotten useless books that gathered cobwebs in a cluttered Oxford subcellar--but for most of us, scrabbling like insects to earn a living for ourselves, the two lost continents of the Western Hemisphere were not much more important than the rings of Saturn--a phenomenon that did not drastically affect the price of eggs. We knew, of course, that the World Council kept its International Patrol circling as near the Atomic Curtain as its aircraft dared to go, but that was a problem for the Twelve Old Men of Geneva, much as the gradually extending icecaps of the two poles were their problem. Theirs and O'Hara's--and the Sunday supplements. 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.