next moment I found myself within a natural enclosure, surrounded on three sides by precipitous rock, so steep as to be almost barren of vegetation, save here and there a clinging vine. Again I looked at the skull. Beyond a doubt its deep blue eyes were directed towards a particular portion of the rocky wall marked by a small depression, shaped like a diamond. Setting the grewsome thing upon a flat rock, I purposely turned the side of the jaw toward the point where the eye had been directed, and breathlessly awaited the result. Slowly, steadily, those lidless eyes turned until they rested again on the diamond-shaped depression."
"And Mitchell?" said his hearer, "did this convince him?"
"Not at first, for he remained near our fire, watching my movements still with an incredulous smile. The smile faded, however, when a moment later I called him to my side and saying, 'Watch the eyes and tell me what you think,' began turning the skull slowly around on the flat rock. The eyes held their focus on the diamond-shaped incision, and I stood up and confronted my friend.
"'Well,' said he, and this time his accent indicated great agitation, 'I believe you are right, and there's some mystery here; let's get to the bottom of it. I'll go to the camp for an axe.' Ten minutes later he returned with the only available tool we possessed, and I began hacking feverishly at the rocky wall, keeping the mark upon which the eyes were riveted as our guide. Before long we had a big slice of the rocky soil cut away, and Mitchell had just taken his turn at the work, when his axe suddenly buried itself in what seemed to be a soft shell of rock, the momentum throwing him flat on his face. The next moment a section of the earth, quite six feet each way, gave way, revealing to our astonished eyes a deep excavation. In the bright light of the morning sun which shone full upon it, lighting up its interior to the rear wall, it seemed about fifty feet inward."
"A sort of cave?" said Leighton.
"Yes, but one made by human hands, as we discovered as soon as we crossed the threshold. The walls were cut and carved in many curious devices, while around the three sides ran a shelf cut in the rock, on which reposed many bones piled in regular heaps.
