During those thirty seconds Thor watched his enemies without moving, while in his deep chest there gathered slowly a low and terrible growl. Not until the pack swept down into the cup of the mountain, giving full tongue again, did he continue his retreat. But it was not flight. He was not afraid. He was going on--because to go on was his business. He was not seeking trouble; he had no desire even to defend his possession of the meadow and the little lake under the mountain. There were other meadows and other lakes, and he was not naturally a lover of fighting. But he was ready to fight. He continued to rumble ominously, and in him there was burning a slow and sullen anger. He buried himself among the rocks; he followed a ledge with Muskwa slinking close at his heels; he climbed over a huge scarp of rock, and twisted among boulders half as big as houses. But not once did he go where Muskwa could not easily follow. Once, when he drew himself from a ledge to a projecting seam of sandstone higher up, and found that Muskwa could not climb it, he came down and went another way. The baying of the dogs was now deep down in the basin. Then it began to rise swiftly, as if on wings, and Thor knew that the pack was coming up the green slide. He stopped again, and this time the wind brought their scent to him full and strong. It was a scent that tightened every muscle in his great body and set strange fires burning in him like raging furnaces. With the dogs came also the _man-smell_! He travelled upward a little faster now, and the fierce and joyous yelping of the dogs seemed scarcely a hundred yards away when he entered a small open space in the wild upheaval of rock. On the mountainside was a wall that rose perpendicularly. Twenty feet on the other side was a sheer fall of a hundred feet, and the way ahead was closed with the exception of a trail scarcely wider than Thor's body by a huge crag of rock that had fallen from the shoulder of the mountain. The big grizzly led Muskwa close up to this crag and the break that opened through it, and then turned suddenly back, so that Muskwa was behind him. In the face of the peril that was almost upon them a mother-bear would have driven Muskwa into the safety of a crevice in the rock wall. Thor did not do this. He fronted the danger that was coming, and reared himself up on his hind quarters. Twenty feet away the trail he had followed swung sharply around a projecting bulge in the perpendicular wall, and with eyes that were now red and terrible Thor watched the trap he had set. The pack was coming full tongue. Fifty yards beyond the bulge the dogs were running shoulder to shoulder, and a moment later the first of them rushed into the arena which Thor had chosen for himself. The bulk of the horde followed so closely that the first dogs were flung under him as they strove frantically to stop themselves in time.