The morning of my arrival at Grand Teton station, on my return from the East, Andrew Hall met me with a warm greeting. "I have been anxiously expecting you," he said, "for I have made some progress towards solving the great mystery. I have not yet reached a conclusion, but I hope soon to let you into the entire secret. In the meantime you can aid me with your companionship, if in no other way, for, since the defeat of the mob, this place has been mighty lonesome. The Grand Teton is a spot that people who have no particular business out here carefully avoid. I am on speaking terms with Dr. Syx, and occasionally, when there is a party to be shown around, I visit his works, and make the best possible use of my eyes. Captain Carter of the military is a capital fellow, and I like to hear his stories of the war in Luzon forty years ago, but I want somebody to whom I can occasionally confide things, and so you are as welcome as moonlight in harvest-time." "Tell me something about that wonderful fight with the mob. Did you see it?" "I did. I had got wind of what Bings intended to do while I was down at Pocotello, and I hurried up here to warn the soldiers, but unfortunately I came too late. Finding the military cooped up in the guard-house and the mob masters of the situation, I kept out of sight on the side of the Teton, and watched the siege with my binocular. I think there was very little of the spectacle that I missed." "What of the mysterious force that the doctor employed to sweep off the assailants?" "Of course, Captain Carter's suggestion that Syx turned molten artemisium from his furnace into a hose-pipe and sprayed the enemy with it is ridiculous. But it is much easier to dismiss Carter's theory than to substitute a better one. I saw the doctor on the roof with a gang of black workmen, and I noticed the flash of polished metal turned rapidly this way and that, but there was some intervening obstacle which prevented me from getting a good view of the mechanism employed. It certainly bore no resemblance to a hose-pipe, or anything of that kind. No emanation was visible from the machine, but it was stupefying to see the mob melt down." "How about the coating of the bodies with artemisium?" "There you are back on the hose-pipe again," laughed Hall. "But, to tell you the truth, I'd rather be excused from expressing an opinion on that operation in wholesale electro-plating just at present. I've the ghost of an idea what it means, but let me test my theory a little before I formulate it. In the meanwhile, won't you take a stroll with me?" "Certainly; nothing could please me better," I replied. "Which way shall we go?" "To the top of the Grand Teton." "What! are you seized with the mountain-climbing fever?" "Not exactly, but I have a particular reason for wishing to take a look from that pinnacle." "I suppose you know the real apex of the peak has never been trodden by man?"