Even fear of dogs and men, unknown quantities in his life until to-day, was now overshadowed by the fear that he had lost Thor.
He did not need eyes to follow the trail.

It was warm under his nose, and he started in the zigzag ascent of the mountain as fast as he could go.
There were places where progress was difficult for his short legs, but he kept on valiantly and hopefully, encouraged by Thor's fresh scent.
It took him a good hour to reach the beginning of the naked shale that reached up to the belt of snow and the sky-line, and it was four o'clock when he started up those last three hundred yards between him and the mountain-top.

Up there he believed he would find Thor.

But he was afraid, and he continued to whimper softly to himself as he dug his little claws bravely into the shale.
Muskwa did not look up to the crest of the peak again after he had started.
To have done that it would have been necessary for him to stop and turn sidewise, for the ascent was steep.

And so, when Muskwa was halfway to the top, it happened that he did not see Langdon and Bruce as they came over the sky-line; and he could not smell them, for the wind was blowing up instead of down.