saw that she was not hurt, and he reached for his revolver.  It was in his holster in the tent.  At his feet was McCready’s whip, and in the passion of the moment he seized it and sprang upon Kazan.  The dog crouched in the snow.  He made no move to escape or to attack.  Only once in his life could he remember having received a beating like that which Thorpe inflicted upon him now.  But not a whimper or a growl escaped him.

[Illustration:  “Not another blow!”]

And then, suddenly, his mistress ran forward and caught the whip poised above Thorpe’s head.

“Not another blow!” she cried, and something in her voice held him from striking.  McCready did not hear what she said then, but a strange look came into Thorpe’s eyes, and without a word he followed his wife into their tent.

“Kazan did not leap at me,” she whispered, and she was trembling with a sudden excitement.  Her face was deathly white.  “That man was behind me,” she went on, clutching her husband by the arm.  “I felt him touch me—­and then Kazan sprang.  He wouldn’t bite me.  It’s the man!  There’s something—­wrong—­”

She was almost sobbing, and Thorpe drew her close in his arms.

“I hadn’t thought before—­but it’s strange,” he said.  “Didn’t McCready say something about knowing the dog?  It’s possible.  Perhaps he’s had Kazan before and abused him in a way that the dog has not forgotten.  To-morrow I’ll find out.  But until I know—­will you promise to keep away from Kazan?”

Isobel gave the promise.  When they came out from the tent Kazan lifted his great head.  The stinging lash had closed one of his eyes and his mouth was dripping blood.  Isobel gave a low sob, but did not go near him.  Half blinded, he knew that his mistress had stopped his punishment, and he whined softly, and wagged his thick tail in the snow.

Never had he felt so miserable as through the long hard hours of the day that followed, when he broke the trail for his team-mates into the North.  One of his eyes was closed and filled with stinging fire, and his body was sore from the blows of the caribou lash.  But it was not physical pain that gave the sullen droop to his head and robbed his body of that keen quick alertness of the lead-dog—­the commander of his mates.  It was his spirit.  For the first time in his life, it was broken.  McCready had beaten him—­long ago; his master had beaten him; and during all this day their voices were fierce and vengeful in his ears.  But it was his mistress who hurt him most.  She held aloof from him, always beyond they reach of his leash; and when they stopped to rest, and again in camp, she looked at him with strange and wondering eyes, and did not speak.  She, too, was ready to beat him.  He believed that, and so slunk away from her and crouched on his belly in the snow.  With him, a broken spirit meant a broken heart, and that night he lurked in one of the deepest shadows about the camp-fire and grieved alone.  None knew that it was grief—­unless it was the girl.  She did not move toward him.  She did not speak to him.  But she watched him closely—­and studied him hardest when he was looking at McCready.