An hour went by, and a second hour. The pale light of the short sunless day was beginning to fade, when a faint far cry arose on the still air. It soared upward with a swift rush, till it reached its topmost note, where it persisted, palpitant and tense, and then slowly died away. It might have been a lost soul wailing, had it not been invested with a certain sad fierceness and hungry eagerness. The front man turned his head until his eyes met the eyes of the man behind. And then, across the narrow oblong box, each nodded to the other.
A second cry arose, piercing the silence with needle–like shrillness. Both men located the sound. It was to the rear, somewhere in the snow expanse they had just traversed. A third and answering cry arose, also to the rear and to the left of the second cry.
"They're after us, Bill," said the man at the front.