For two minutes Thor sat on his haunches without moving a muscle of his great body except those twitching thews in his nose.

Deep down in this cup under the mountain it was difficult even for sound to reach him.  Quickly he swung down on all fours and made for the green slope to the southward, at the top of which the band of sheep had slept during the preceding night.  Muskwa hurried after.

A hundred yards up the slope Thor stopped and turned.  Again he reared himself.  Now Muskwa also faced to the north.  A sudden downward drift of the wind brought the barking of the dogs to them clearly.

Less than half a mile away Langdon’s pack of trained Airedales were hot on the scent.  Their baying was filled with the fierce excitement which told Bruce and Langdon, a quarter of a mile behind them, that they were close upon their prey.

And even more than it thrilled them did the tongueing of the dogs thrill Thor.  Again it was instinct that told him a new enemy had come into his world.  He was not afraid.  But that instinct urged him to retreat, and he went higher until he came to a part of the mountain that was rough and broken, where once more he halted.

This time he waited.  Whatever the menace was it was drawing nearer with the swiftness of the wind.  He could hear it coming up the slope that sheltered the basin from the valley.

The crest of that slope was just about on a level with Thor’s eyes, and as he looked the leader of the pack came up over the edge of it and stood for a moment outlined against the sky.  The others followed quickly, and for perhaps thirty seconds they stood rigid on the cap of the hill, looking down into the basin at their feet and sniffing the heavy scent with which it was filled.

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.