Thrice he tried to knock him over, then repeated the trick and broke the right fore leg.

Despite the pain and helplessness, Spitz struggled madly to keep up.

He saw the silent circle, with gleaming eyes, lolling tongues, and silvery breaths drifting upward, closing in upon him as he had seen similar circles close in upon beaten antagonists in the past.

Only this time he was the one who was beaten.
There was no hope for him.

Buck was inexorable.