The Indian never moved a muscle; but his eyes roved everywhere.

He, too, noticed the absence of the chief.
At this moment from out of the depths of the woods came a swelling sigh, like the moan of the night wind.

It rose and died away, leaving the silence apparently all the deeper.
A shudder ran over Joe's frame.

Fascinated, he watched the guard.
The Indian uttered a low gasp; his eyes started and glared wildly; he rose very slowly to his full height and stood waiting, listening.
The dark hand which held the tomahawk trembled so that little glints of moonlight glanced from the bright steel.
From far back in the forest-deeps came that same low moaning: "Um-m-mm-woo-o-o-o!" It rose from a faint murmur and swelled to a deep moan, soft but clear, and ended in a wail like that of a lost soul.
The break it made in that dead silence was awful.

Joe's blood seemed to have curdled and frozen; a cold sweat oozed from his skin, and it was as if a clammy hand clutched at his heart.