"You can't conceive," asked Thrale, "of any cataclysm that would involve a return to the old segregation of nations, and bring about a new epoch beginning with separated peoples evolving on more or less racial lines?" Gurney pondered for a moment or two and then shook his head. "Little wonder," said Thrale, "I had often considered this problem, and I could think of no upheaval which would bring about the familiar effect of submersion. Years ago there was always the possibility of a European war, but even that would have only a temporary effect despite the forecast of Mr Wells in The War in the Air. No, I considered and wondered if my theory was faulty. I was willing to reject it if I could find a flaw...." "And then?" questioned Gurney. Thrale leaned forward again and once more compelled the other's fascinated attention. "And then, when I was in Northern China, seven weeks ago, I saw a solution, so appalling, so inconceivably ghastly, that I rejected it with horror. For days I went about fighting my own conviction. I couldn't believe it! By God, I would not believe it! "There, within a hundred and fifty miles of the border of Tibet, the outside forces have planted a seed which has been maturing in secret for more than a year. There that seed has taken root, and from that centre is spreading more and more rapidly, and it may spread over the whole world. It is like some filthily poisonous and incredibly prolific weed, and its seeds, now that it has once established itself, are borne by every wind, dropping here and there in an ever-widening circle, every seed becoming a fresh centre of distribution outwards." "But what, in Heaven's name, is the weed?" whispered Gurney. "A new disease--a new plague--unknown by man, against which, so far as we know, he has no weapon. In those scattered villages among the mountains there are no men left to work. Everything is done by women. They are prohibited more fiercely than any leper settlement. No one dares to approach within five miles of them. But every week or two another village is smitten, and the inhabitants fly in terror and carry the infection with them. "Gurney, it's come to Europe! There are new centres of distribution in Russia at the present time. If it isn't stopped it will come to England. And it doesn't decimate the population. It wipes the men clean out of existence; not one man in ten thousand, the Chinese say, escapes. "Is it possible that this can be the means of the 'higher forces' I spoke of, the means to segregate the nations once more?" III--LONDON'S INCREDULITY 1