disappearing without warning, trailing as the white ermine follows its
prey, noiseless, alert, his body responding sinuously and without
apparent effort to the working commands of his brain.

Where the forest broke into an open, lighted by the stars, he found
blood in the footprints of the leading dog. Half-way across the open,
he saw where the leader had swung out from the trail and the others of
the pack had crowded about him, to be urged on by the lashings of the
man's whip. Other signs of the pack's growing exhaustion followed
close.

The man now traveled beside the sledge where the trail was rough, and
rode where it was smooth and hard. The deep imprints of his heeled
boots in the soft snow showed that he ran for only a short distance at
a time--a hundred yards or less--and that after each running spell he
brought the pack to a walk. He was heavy and lacked endurance, and
this discovery brought a low cry of exultation to Jan's lips.

He fell into a dog-trot. Mile after mile dropped behind him; other
miles were ahead of him, an endless wilderness of miles, and through
them the tired pack persisted, keeping always beyond sound and vision.

The stars began fading out of the skies. The shadows of the forest
grew deeper and blacker, and where the aurora had lightened the
heavens there crept the somber gray film that preceded dawn by three
hours.

Jan followed more and more slowly. There was hard-breathing effort now
in his running--effort that caused him physical pain and discomfort.
His feet stumbled occasionally in the snow; his legs, from thigh to