it does not see. Beyond the rock, built close against it so that
the rear wall must have been the face of the ledge, a little rock
cabin squatted secretively. One small window, with two panes of
glass was set high under the eaves on the side toward Casey.
Cleverly concealed it was, built to resemble the ledge. Visible
from one side only, and that was the side where Casey stood. At
the back the sloping boulder, untouched, impregnable; at the
north and west, a twist of the ledge that hid the cabin
completely in a niche. It was the window on the south side that
betrayed it.

So here was what the boulder concealed,--and yet, Casey was not
satisfied with the discovery. Unconsciously he reached for his
gun. This, he told himself, must be the secret habitation of the
fiend who shot from rim-rocks with terrible precision at harmless
prospectors and their burros.

Casey squinted up at the sun and turned his level gaze again upon
the cabin. Reason told him that the man with the rifle was still
watching for a pot shot at him and Barney, and that there was
nothing whatever to indicate the presence of only one man in the
camp below. Had he been glimpsed once during the climb, he would
have been fired upon; he would never have been given the chance
to gain the top and find this cabin.

The place looked deserted. His practical, everyday mind told him
it was empty for the time being. But he felt queer and
uncomfortable, nevertheless. He sneaked along the ledge to the
cabin, flattened himself against the corner next the gray boulder
and waited there for a minute. He felt the flesh stiffening on