At another time he would have played his favourite trick of detouring so that the danger would be ahead of him, with the wind in his favour. Caution had now become secondary to his desire to find his mate. The dogs were less than half a mile away when he stopped suddenly, sniffed the air for a moment, and then went on swiftly until he was halted by a narrow ravine. Up that ravine Iskwao was coming from a dip lower down the mountain, and she was running. The yelping of the pack was fierce and close when Thor scrambled down in time to meet her as she rushed upward. Iskwao paused for a single moment, smelled noses with Thor, and then went on, her ears laid back flat and sullen and her throat filled with growling menace. Thor followed her, and he also growled. He knew that his mate was fleeing from the dogs, and again that deadly and slowly increasing wrath swept through him as he climbed after her higher up the mountain. In such an hour as this Thor was at his worst. He was a fighter when pursued as the dogs had pursued him a week before--but he was a demon, terrible and without mercy, when danger threatened his mate. He fell farther and farther behind Iskwao, and twice lie turned, his fangs gleaming under drawn lips, and his defiance rolling back upon his enemies in low thunder. When he came up out of the coulee he was in the shadow of the peak, and Iskwao had already disappeared in her skyward scramble. Where she had gone was a wild chaos of rock-slide and the piled-up débris of fallen and shattered masses of sandstone crag. The sky-line was not more than three hundred yards above him. He looked up. Iskwao was among the rocks, and here was the place to fight. The dogs were close upon him now. They were coming up the last stretch of the coulee, baying loudly. Thor turned about, and waited for them. Half a mile to the south, looking through his glasses, Langdon saw Thor, and at almost the same instant the dogs appeared over the edge of the coulee. He had ridden halfway up the mountain; from that point he had climbed higher, and was following a well-beaten sheep trail at about the same altitude as Thor. From where he stood the valley lay under his glasses for miles. He did not have far to look to discover Bruce and the Indian. They were dismounting at the foot of the coulee, and as he gazed they ran quickly into it and disappeared.