Robert Silverberg 
New Springtime [EPUB ebook] 

The death-stars had come, and they had kept on coming for hundreds of thousands of years, falling upon the Earth, swept upon it by a vagrant star that had passed through the outer reaches of the solar system. They brought with them a time of unending darkness and cold. It was an event that occured every twenty-six million years, and there was no turning it aside. But all that was done with now. At last the death-stars had ceased to fall, the sky had cleared of dust and cinders, the sun’s warmth again was able to break through the clouds. The glaciers relinquished their hold on the land; the Long Winter ended; the New Springtime began. The world was born anew. Now each year was warmer than the last. The fair seasons of spring and summer, long lost from the world, came again with increasing power. And the People, having survived the dark time in their sealed cocoons, were spreading rapidly across the fertile land. But others were already there. The hjjks, the somber cold-eyed insect-folk, had never retreated, even at the time of greatest chill. The world had fallen to them by default, and they had been its sole masters for seven hundred thousand years. They were not likely to share it gladly now . . .