following the base of the cliffs. The tracks of Noddle and Wolf were
plainly visible in the dust. Hare felt that if they ever led out into
the immense airy space of the desert all hope of finding Mescal must be
abandoned.

They trailed the tracks of the dog and burro to Bitter Seeps, a shallow
spring of alkali, and there lost all track of them. The path up the
cliffs to the Navajo ranges was bare, time-worn in solid rock, and showed
only the imprint of age. Desertward the ridges of shale, the washes of
copper earth, baked in the sun, gave no sign of the fugitives' course.
August Naab shrugged his broad shoulders and pointed his horse to the
cliff. It was dusk when they surmounted it.

They camped in the lee of an uplifting crag. When the wind died down the
night was no longer unpleasantly cool; and Hare, finding August Naab
uncommunicative and sleepy, strolled along the rim of the cliff, as he
had been wont to do in the sheep-herding days. He could scarcely
dissociate them from the present, for the bitter-sweet smell of tree and
bush, the almost inaudible sigh of breeze, the opening and shutting of
the great white stars in the blue dome, the silence, the sense of the
invisible void beneath him--all were thought-provoking parts of that past
of which nothing could ever be forgotten. And it was a silence which
brought much to the ear that could hear. It was a silence penetrated by
faint and distant sounds, by mourning wolf, or moan of wind in a
splintered crag. Weird and low, an inarticulate voice, it wailed up from
the desert, winding along the hollow trail, freeing itself in the wide
air, and dying away. He had often heard the scream of lion and cry of
wildcat, but this was the strange sound of which August Naab had told
him, the mysterious call of canyon and desert night.