These men were now on a three days' leave of absence. The United States--the only formidable power of the Occident that had so far escaped being wiped out by the air fleets of Asia, could ill spare either; but science had not yet found a way to relieve the fatigue that comes with constant war. Above them the aviators could see the deep blue-black sky, sprinkled with stars because of the rarity of the atmosphere. Beneath rolled an ever-changing panorama of earth, seemingly turned up at the edges like an enormous saucer. Now they were over the Gulf of Mexico veiled in its gray-blue mist; now above the verdant agricultural districts of Central America, long ago occupied by the invaders. A little more than three hours after they had set out from Chicago, the young men hung over the snow-capped pinnacles of the Andes, which looked like mere ash heaps far beneath. Here was one of the few spots on earth that did not yet resound with the din of war; it was such a place they sought. Presently the airboat began to descend in a long spiral; a few minutes later it settled gently at the edge of a little adobe village on the eastern slope of the mountains. The Legend of the Mountain A flier was an unusual sight here and the inquisitive inhabitants, men, women and children, crowded around to get a glimpse at the wonderful machine. There was nothing resembling a hostelry in the village; but, when the worthy Señor Hernando Diaz, its richest citizen, learned that these young men were soldiers like his own three sons who were fighting against the Asiatics in Argentina, he offered his hospitality. After the evening meal Señor Diaz and his guests repaired to a broad veranda which faced west. For quite a time the three men remained silent. Pelton and Calhoun were absorbed in the grandeur of the mountains over which dusk was settling, and Hernando Diaz knew too well the power of silence and the spell of that majestic sight, to break it with words. At length Calhoun murmured musingly: "God is up there--God and Peace. Even war couldn't disturb the eternal serenity of those Andes." He spoke in Spanish. Both Calhoun and Pelton had a fairly complete mastery of that language. Diaz leaned far forward in his chair: "God in those mountains, Señor? Ah, yes, perhaps in the great peaks far off; but do you see that one which is quite near? It is less than two thousand meters high and at its summit there is a small depression or crater. Madre de Dios--there indeed is the lair of Satan!" A quizzical smile came over Calhoun's lips. He turned toward the Ecuadorian: "I'm afraid the gentleman you mention has gone north to help with the big row up there. But let's hear the rest of what you were going to say. I'm intensely interested and I think that Joe is perfectly willing to listen too."