A strange look had come into his face.

He was staring hard at Kazan.
Suddenly he leaned forward, with both hands on his knees, and for a tense moment or two he seemed to forget that Isobel Thorpe's wonderful blue eyes were looking at him.
"Hoo-koosh, Pedro--_charge_!" That one word--_charge_--was taught only to the dogs in the service of the Northwest Mounted Police.

Kazan did not move.

McCready straightened, and quick as a shot sent the long lash of his whip curling out into the night with a crack like a pistol report.
"Charge, Pedro--_charge_!" The rumble in Kazan's throat deepened to a snarling growl, but not a muscle of his body moved.

McCready turned to Thorpe.
"I could have sworn that I knew that dog," he said.