The big gray leaders did not mind the night or the wind or the rain, which they had known all their lives, and which they counted as nothing, but they always had involuntary suspicion of human figures, whether living or not, and they approached slowly, wrinkling back their noses and sniffing the wind which blew from them instead of the five figures.

But their confidence increased as they advanced.

They had found many such burned houses as this, but they had found nothing among the ruins except what they wished.
The big leaders advanced more boldly, glaring straight at the human figures, a slight froth on their lips, the lips themselves curling back farther from the strong white teeth.

The outer ends of the concave semicircle also drew in.

The whole pack was about to spring upon its unresisting prey, and it is, no doubt, true that many a wolfish pulse beat a little higher in anticipation.