Silently, swiftly—­the wolf now in every movement, Kazan came to his feet.  He forgot the chain that held him.  Ten feet away stood the enemy he hated above all others he had ever known.  Every ounce of strength in his splendid body gathered itself for the spring.  And then he leaped.  This time the chain did not pull him back, almost neck-broken.  Age and the elements had weakened the leather collar he had worn since the days of his slavery in the traces, and it gave way with a snap.  Sandy turned, and in a second leap Kazan’s fangs sank into the flesh of his arm.  With a startled cry the man fell, and as they rolled over on the ground the big Dane’s deep voice rolled out in thunderous alarm as he tugged at his leash.  In the fall Kazan’s hold was broken.  In an instant he was on his feet, ready for another attack.  And then the change came.  He was free.  The collar was gone from his neck.  The forest, the stars, the whispering wind were all about him. Here were men, and off there was—­Gray Wolf!  His ears dropped, and he turned swiftly, and slipped like a shadow back into the glorious freedom of his world.

A hundred yards away something stopped him for an instant.  It was not the big Dane’s voice, but the sharp crack—­crack—­crack, of the little professor’s automatic.  And above that sound there rose the voice of Sandy McTrigger in a weird and terrible cry.

CHAPTER XXVI

AN EMPTY WORLD

Mile after mile Kazan went on.  For a time he was oppressed by the shivering note of death that had come to him in Sandy McTrigger’s cry, and he slipped through the banskians like a shadow, his ears flattened, his tail trailing, his hindquarters betraying that curious slinking quality of the wolf and dog stealing away from danger.  Then he came out upon a plain, and the stillness, the billion stars in the clear vault of the sky, and the keen air that carried with it a breath of the Arctic barrens made him alert and questioning.  He faced the direction of the wind.  Somewhere off there, far to the south and west, was Gray Wolf.  For the first time in many weeks he sat back on his haunches and gave the deep and vibrant call that echoed weirdly for miles about him.  Back in the banskians the big Dane heard it, and whined.  From over the still body of Sandy McTrigger the little professor looked up with a white tense face, and listened for a second cry.  But instinct told Kazan that to that first call there would be no answer, and now he struck out swiftly, galloping mile after mile, as a dog follows the trail of its master home.  He did not turn hack to the lake, nor was his direction toward Red Gold City.  As straight as he might have followed a road blazed by the hand of man he cut across the forty miles of plain and swamp and forest and rocky ridge that lay between him and the McFarlane.  All that night he did not call again for Gray Wolf.  With him reasoning was a process brought about by habit—­by precedent—­and as Gray Wolf had waited for him many times before he knew that she would be waiting for him now near the sand-bar.