It was, thought Burl, a dim day, but this he supposed was due to the earliness of the morning. As the Sun rose, it would rapidly bring the temperatures up, and its unshielded rays would force them to cover up as they climbed along the high mountain passes. The sky was cloudless as usual. Burl assumed that the dimness was due to volcanic dust, or some unseen high cloud far away. And, indeed, as the expedition came to life, and the day began in earnest, nobody paid any attention to the fact that the Sun was not quite so warm as it should have been. The Denning expedition, questing among the untracked and forgotten byways of the lost Inca ruins in the vast, jagged mountains of inland Peru, was not alone in failing to notice the subtle channeling away of the Sun's warmth and brilliance. They were, in this respect, one with virtually the entire population of Earth. In New York, in San Francisco, in Philadelphia and Kansas City, people going about their day's chores simply assumed that there must be clouds somewhere--the temperature only slightly less than normal for a July day. A few men shaded their eyes and looked about, noticing that the heat was not so intense--and thought it a blessing. In some places in Europe, there were clouds and a little rain, and the dimness was ascribed to this. It was raining in much of Asia, and there were scattered afternoon showers throughout Latin America, which were standard for the season. There was a flurry of snow in Melbourne and a cold blow in Santiago de Chile. The men in the weather bureaus noted on their day's charts that temperatures were a few degrees lower than had been predicted, but that was nothing unusual. Weather was still not entirely predictable, even with the advances of meteorology that were to be expected of the latter years of the twentieth century. The world was reading about other things than the vagaries of the weather. In the United States, baseball occupied the headlines, and the nonathletic-minded could find some speculative interest in the completion of another manned space platform racing along in its eternal orbit twelve thousand miles away from Earth's surface. The U.S. Moon Base in the center of the Crater Ptolemaeus had described the appearance of this platform in an interesting radio dispatch which appeared on the first pages of most newspapers. The third prober rocket sent to Venus had been unreported for the tenth day after penetrating the clouds that hid that planet's surface from human eyes. It was, like its two predecessors, a minimum-sized, unmanned instrument device designed to penetrate the clouds and radio back data on the nature of the Venusian atmosphere and the surface. But after its first report, nothing more had been heard.