The clear stars before him took to shuddering and he knew why; they shuddered at sight of what was behind him. He had never divined before that strange Things hid themselves from men, under pretence of being snow-clad mounds of swaying trees; but now they came slipping out from their harmless covers to follow him, and mock at his impotence to make a kindred Thing resolve to truer form. He knew the air behind him was thronged; he heard the hum of innumerable murmurings together; but his eyes could never catch them - they were too swift and nimble; but he knew they were there, because, on a backward glance, he saw the snow mounds surge as they grovelled flatlings out of sight; he saw the trees reel as they screwed themselves rigid past recognition among the boughs.