Fair went on ahead, still keeping to the water, though both horses were pretty well winded with the hard going it afforded, and at last drew up to let Selwood come alongside.
He sat still for a moment.
“Listen a bit,” he said, “do you hear anything different from the sounds of water and the murmuring of the big cut?”
The sheriff listened sharply.
“Yes,” he said presently, “I do. Sounds like wind.”
“Exactly. Yet there isn’t any wind, more than the draft which always draws down the cañon. Now look closely at the wall. Watch that clump of willows yonder.”
He pointed ahead and to the left where a dense green growth stood alone against the rock face.
Selwood looked and for a moment his face did not change.
Then, suddenly, his mouth fell open, his eyes grew wide with astonishment.
“Great Scott!” he said, “they’re blowing out from the wall! There’s wind behind them!”