In a few minutes he had the coffee-pot boiling over a charcoal brazier. I believe that aroma is about the most pleasant that ever reached my nostrils. I was too much absorbed in it to do much talking, but Melvar sat down on one of Austen's rustic stools and gave him an account of our adventures. When the coffee was done, Austen served a meal consisting in addition of a great pot of steaming soup made of the yellow fruits cooked with the tender roots of the red plants. That stands out in my memory as one of the truly magnificent repasts that have ever been laid before me. When we had finished Melvar retired to Austen's bunk, and Naro and I lay down on a blanket on the laboratory floor. I went to sleep at once, and, if I may credit the word of our host, slept for thirty-seven and a half hours. Although I am inclined to believe that is an exaggeration. At any rate, when I got up, I felt a new man. Austen had set up the apparatus we brought. He had a test tube full of the silver liquid set up in a beam of X-rays, and the spectroscope in position to examine the dense purple gas that was rising from the stuff. "How is it coming?" I asked him. He shook his head sadly. "I don't know," he said. "I have a theory, but it doesn't seem to work out right. The key is in sight but it always eludes me. There is energy stored in the silver liquid. It may be that that amazing thing in the sky stores the energy of sunlight in the stuff. You know that the energy in sunlight amounts to something over one horsepower for each square yard on which it falls. Or perhaps the atomic energy of the gases in the air is released. It seems impossible to find the key, although I have been able to analyze the stuff pretty accurately. If I had it I could make the silver stuff go off like ten times its weight of T.N.T." "Do you think," I asked him eagerly, "that you could set off some of it and wipe out the _Krimlu_?" "Winfield," the old scientist soberly replied, "even if you could, would you wipe out a whole civilization--a science so high as that which made the Silver Lake--a culture equal to, if not above, that of our own world?" "If you had seen those purple things--men and women that are old and hideous, and fearfully strong and malignant--you couldn't move too quickly to blot them off the earth," I cried. "I have seen," he said seriously. "I have seen the purple monsters, and they are terrible enough. But they are not the masters. They are but the servants, or perhaps I should say the machines, of a higher power. I told you that I had been exploring a bit. I have seen some strange things.