An old and practiced mountaineer, he had never been known to lose sense of direction or sense of distance, and he was an hour overdue when the sun went down and the soft, beautiful mountain twilight began.
There were other reasons which would ordinarily have disturbed Bill and brought him home even ahead of time.

Snow had fallen heavily above the timberline a few days before, and now the keen whistling of the wind and the swift curtaining of clouds, which was drawing across the sky, threatened a new storm that might even reach down to the shack.
And yet no Bill appeared.
The brothers waited in the shack, and the darkness was increasing.

Any one of a number of things might have happened to their father, but they were not worried.

For one thing, they wasted no love on the stern old man.

They knew well enough that he had plenty of money, but he kept them here to a dog's life in the shack, and they hated him for it.