He glanced back at the gray-black creature that followed at the heels of his horse; and now, at twilight's graying, he saw that a significant and startling change had come over him. He no longer trotted easily behind them. He came stalking, almost as if in the hunt, his ears pointing, his neck hairs bristling, and there were the beginnings of curious, lurid lightnings in his eyes. There could be but one answer. He had been swept away in the current of madness that sweeps the forest at the fall of darkness: the age-old intoxication of the wilderness night. The hunting hours were at hand. The creatures of claw and fang were coming into their own. Fenris was shivering all over with those dark wood's passions that not even the wisest naturalist can fully understand. The air was tingling and electric, just as Ben recalled it a thousand nights. Everywhere the hunters were leaving their lairs and starting forth; grasses moved and brush-clumps rustled; blood was hot and savage eyes were shot with fire. The mink, with unspeakable savagery, took the trail of a snow-shoe rabbit beside the river-bed; a lynx with pale, green, luminous eyes began his stalk of a tree squirrel, and various of Fenris' fellows--pack brothers except for his own relations with men--sang a song that was old when the mountains were new as they raced, black in silhouette against the paling sky, along a snowy ridge. Ben felt a quickening of his own senses, not knowing why. _His_ blood, too, spurted inordinately fast through his veins, and his flesh seemed to creep and tingle. There could be no surer proof of his legitimacy as a son of the wilderness. The passions that maddened the first men, near to the beasts they hunted in their ancient forests, returned in all their fullness. The dusk deepened. The trail dimmed so that the eye had to strain to follow it. Complex and weird were the passions invoked to-night, but not even to the gray wolf that is, beyond all other creatures, the embodiment of the wilderness spirit, did there come such a madness, such a dark and terrible lust, as that which cursed a certain wayfarer beyond the next bend in the river. This was not one of the forest people, neither the lynx, nor the hunting otter, nor even the venerable grizzly with whom no one contests the trail. It was a human being,--a man of youthful body and strong, deeply lined, yet savage face. A close observer would have noticed the faintest tremor and shiver throughout his body. His eyes were very bright, vivid even in the dying day. He was deeply lost in his own mood, seemingly oblivious to the whole world about him. He carried a rifle in his hands. He was on his way to report to his chief; and just what would be forthcoming he did not know. But if too much objection were raised and affairs got to a crucial stage, he had nothing to fear. He had learned a certain lesson--an avenue to triumph. It was strange that he had never hit upon it before.