The point whence it came was a clump of rocks hardly fifty feet distant, and he fancied he recognized the voice as Bill Tozer's.

To his relief he could see no one, and it was safe, therefore, to assume that no one as yet saw him.
The ground was favorable, and by using the utmost care he secured a position from which he discovered Tozer and Motoza in conversation.

The white man was sitting on a boulder, while the Sioux was standing in front of him, gesticulating as if angry over something that had been proposed or said.

Tozer was smoking a pipe, and seemed cool and collected, though the exclamation which had betrayed him indicated that it had not been thus from the beginning.
It was an important discovery for Hazletine to make, but it was attended by two exasperating facts: the interview was nearly over, and the words that remained to be spoken were uttered in such moderate tones that he could not hear a syllable.

If the couple had been obliging enough to raise their voices, it is probable that the knowledge sought by the eavesdropper would have soon been at his command.
But nothing of that nature took place.