For a time I stood waiting tensely, with my rifle in my hand, but I was very tired and weak. Presently I got out my flashlight and examined the place. It was a little cell, apparently hewn in the living rock of the mountain. There was nothing in the way of furniture except a sort of padded shelf, or bed, at the back. I sat down upon it, and presently went to sleep there, though I had no intention of doing so. * * * * * Austen's Letter The next I knew, someone was shaking my arm, and shouting strange words in my ear. I opened my eyes. Standing before me was a young man. In one hand he held a crystal globe filled with a glowing, phosphorescent stuff, faintly lighting the little apartment. I sat up slowly, for my limbs were stiff. The gun was still in my hand. Without saying anything more, the young fellow pointed to a tray that he had set by me on the shelf. It contained a crystal pitcher of aromatic liquid, and a dash of the yellow fruit. I gulped down some of the drink, and ate a few of the fruits, feeling refreshed almost immediately. Then the boy--he was not more than sixteen years of age--thrust into my hand an envelope addressed in the familiar handwriting of Austen. He handed me the light and walked up the stone stairs. With feeling that well may be imagined, I tore open the envelope and read, in the faint light of the glowing bulb, the words of my old friend. "Astran, in the Mountain of the Moon, June 16, 1927. "To whomsoever of my own race this may be delivered: "Since you must so far have traveled the mysterious dangers of this strange world, it is needless for me to dwell upon them. I write this brief missive for the information of anyone who shall happen to find the way in here in the future, and in order that the riddle of my own disappearance may some time be cleared up, if I fail to return. For I intend to explore the region beyond this lake--I call it the Silver Lake--or to lose my life in the attempt. "My name is Horace Austen. I came to the Great Victoria Desert to investigate the sculptured columns reported by Hamilton, far to the west of here. I found the ruins and incredibly ancient they are. They must date from fifty thousand years ago, at the latest. Among them was an amazing pictographical record of a race of men driven by the drying up of their country to emigrate to the crater of a great mountain nearby. There was no mistaking the meaning. I was, of course, intensely interested, for nothing of the kind had ever been reported in Australia, and certainly the people depicted were not Bushmen.