Curiosity led him over the trail.

He had not followed it more than two hundred yards when he stopped in sudden astonishment.

Plainly marked in the snow before him was the trail of a pair of snow-shoes! Whoever had been there had passed since he shot the fox, for the imprints of the animal's feet were buried under those of the snow-shoes.
Who was the other person in the chasm?
Was it Wabi?
Had Mukoki or he come to join him?
Or-- He looked again at the snow-shoe trail.

It was a peculiar trail, unlike the one made by his own shoes.

The imprints were a foot longer than his own, and narrower.