And again it was this world of contrast that drove home the conviction with its sickening certainty. A world of beauty, of delicate colors, of sweeping oceans and gleaming shores and towering cities with their grace and beauty and elfin splendor yet a world that shuddered beneath this devouring plague of grublike men. * * * * * They swept past cities and towns and over many miles of open land before their craft swung eastward toward the dark horizon. The master gave another order into the speaking tube and their ship shot forward, faster and yet faster, with a speed that pressed them heavily into their seats. Behind them was the glory of the sunlit clouds; ahead the gloomy gray-black masses that must make a stygian night sky over this lonely world--a world cut off by that vaporous shell from all communion with the stars. They were over the water; before them a dark ocean reached out in forbidding emptiness to a darker horizon. Ahead, the only broken line in the vast level expanse was a mountain rising abruptly from the sea. It was a volcanic cone surmounting an island; the sunlight's glow reflected from behind them against the sombre mass that lifted toward the clouds. Their ship was high enough to clear it, but instead it swung, as McGuire watched, toward the south. The island drifted past, and again they were on their course. But to the flyer there were significant facts that could not pass unobserved. Their own ship had swung in a great circle to avoid this mountain. And all through the skies were others that did the same. The air above and about the grim sentinel peak was devoid of flying shapes. McGuire caught the eyes of the councilor, their keeper. "What is that?" he asked, though he knew the words were lost on the other. He nodded his head toward the distant peak, and his question was plainly in regard to the island. And for the first time since their coming to this wild world, he saw, flashing across the features of one of these men, a trace of emotion that could only be construed as fear. The slitted cat eyes lost their look of complacent superiority. They widened involuntarily, and the face was drained of its blotched color. There was fear, terror unmistakable, though it showed for but an instant. He had control of his features almost at once, but the flyer had read their story. Here was something that gave pause to this race of conquering vermin; a place in the expanse of this vast sea that brought panic to their hearts. And there came to him, as he stowed the remembrance away in his mind, the first glow of hope. These things could fear a mountain; it might be that they could be brought to fear a man. * * * * *