"Sands looked at me with a puzzled frown.
"'Hell!' he expostulated, 'there's not that much radium in the whole world and we wouldn't know it if we seen a lake of it. Looks like some green salt solution to me and indications point to some funny deposits here! What's that unearthly noise?'
"I cupped my hands behind my ears to catch the sound that Sands had heard. My hair literally stood on ends. Spooky? Lord! I couldn't have moved a foot if I wanted to. I was glued to the spot. The weird sound, like the low moan of a woman in mortal agony, issued from the circular cave surrounding the luminous pool. It grew louder until the Manalava Plain groaned under the tumult. The sounds penetrated to the core of the brain and seemed to beckon us down into the crater. Sands was swaying to and fro as he stood on the slight parapet overlooking the crater, in perfect rhythm to the tempo of the devilish sounds. I felt that I too was keeping the same accompaniment and it was with an effort that I broke the spell.
"My hand dropped to my gun butt. I tore it out of its holster and fired rapidly, thumbing the hammer, into the pool. Sands yelled. Like a living fountain, long columns of luminous green and red and violet flame shot up to the parapet. Simultaneously we both leaped back. The air seemed alive with some mysterious vibrations. Finally it died away and the tumult issuing from the circular cave settled down to a low, steady hum. We once again stood on the crater's escarpment and looked within. The pool was glittering restlessly.
"'We might as well have a close look at that pool, pardner,' Sands reminded me as I stood rooted on the edge of the crater, studying the formation surrounding the pool. 'I can't make it out. If it's some radium compound, you'll be a rich man. Your wife an' kids back in Balch will be needin' it, I'm thinkin'. Let's go down.'
"Sands stepped over the escarpment. I followed him down into the crater. We paused about twenty feet from the edge of the pool. The heat was terrific—so great that it caused the blood to race to my head, and my heart to beat rapidly. And more intense became that mysterious vibration in the air, and a something that seemed to be eating into my flesh. I remarked about the phenomenon to Sands and told him that it must have been caused by some unknown power of radium. Rather than risk touching the stuff I threw a piece of cloth on it. There was a little sizzle and the cloth seemed literally to vanish before our eyes! He then took his revolver and dipped it in. The hard steel of the barrel melted like lead in a blast furnace, yet the butt in his hand did not heat beyond sun-temperature. The melted steel floated to the surface like slag and drifted out into the center of the pool, to sink again in a tiny whirl. Sands fondled his useless gun speculatively.
"'Pardner,' he said, 'You're lookin' into a pool of some radium compound! It must be radium for I've seen about everything else in its line. If Allie and her father came too close to this, you can imagine what happened to them. I fear the worst.'
"'Well,' I said, 'I don't like to think that your friends ended near the pool. We might see some bones if they did. Let's take a look under these overhanging shelves. The caves might tell us something.'
"'I don't reckon we'll find anything, pardner,' Sands returned, sick at heart and utterly dejected.
"'Can't tell! We've seen so many strange things that I'm interested,' I said.