"You know that lightning in the air causes a union of nitrogen and oxygen, to form nitrous and nitric acids, which may later release their energy in the explosion of gun powder or nitroglycerine. In much the same way the force that forms the silver fluid utilizes the photochemical effect of sunlight to build up a complex molecule containing oxygen, nitrogen, and the inert gases of the helium group. It is very unstable, and may be disrupted with the release of a great amount of energy. I was able to detect the characteristic lines of most of the gases in the luminous spectrum of the purple gas, but not until I had analyzed the light of the opalescent flame, and made my deductions from that, was I able to derive the equations and arrive at the precise structural formula, and at the exact wave length necessary to break down the molecule." He proceeded to launch into a detailed technical discussion of the process of analysis he had used, and of the methods of inductive reasoning by which he had arrived at his conclusion. It was rather deep for me, and I am afraid some of the salient points have already slipped my mind. But I doubt that the general reader would be interested in it anyhow. Something more important was on my mind. "Have you found out enough?" I asked. "Can you blow up the stuff? Can you wipe out the _Krimlu_?" "I am not sure," he said, "but I think, if I could get at that machine with a little of my equipment I could manipulate it to make it go off like a thousand tons of dynamite. The silver stuff runs into the cylinder and is converted into pure vibrant energy. If I could just speed up the process a bit! "The _Krimlu_ seem to live underground like ants. A month ago I found an opening into their world near the cliffs, south of the fall. There are the shafts where their ships come out, ventilator tubes, and funnels for the purple smoke from their engines. I will go down one of the shafts and see what can be done." "You mean we will go," I told him. "You don't think--" "There is no need for you to risk your life," he said in a voice purposely brusque to hide his emotion. "I can do as much by myself. Then there is Melvar. We must get her out of here if we can. I think a great deal of her. If we both should go--and not come back--. No, I want you to stay on top. I know I can trust you to treat her fairly. If I can blast down the earth on their underground world, we might be able to make it back around the Silver Sea, and eventually to the outside." "You can trust me, sir, to care for her to the best of my ability," I told him, looking at the sandal on my right foot, and trying, without notable success, to keep my voice even and casual. "Really," he cried, looking at me intensely, "do you love her?" * * * * * A Declaration I admitted that I did, even using, as I remember the occasion, rather an enthusiastic, if hackneyed phrase to describe my feeling.