Then Sam thought of examining it under the microscope. He found that it was full of microscopic bubbles--hollow places! By later experiment, we found that the metal was just a sponge of the strange alloy, filled with tiny bubbles of helium gas, under considerable pressure. Sam presently formulated the theory that the alloy, when formed, had contained considerable amounts of radium compounds; and that the alpha particles, or charged helium atoms, thrown off by the disintegration of the radium, while the metal was in a semi-plastic state, had been imprisoned in it. But it was not until later--much later--that we got the true meaning of it--that we understood the insidious force that acted in the metal, to make human beings slaves to it! So the days went by--happy, carefree days for me. I knew real joy for the first time in my life. Since youth I had known the Green Girl in my fancy. I had longed to find her, with a restless, hopeless longing that had left me discontented and unhappy, whatever my surroundings. Now, at last, she was really mine. I loved her with a singleness and intensity of affection that turned all my emotion in one direction, so I felt little fear or care for anything else. One day, when we sat like children together on a cool, moss-covered rock beneath a great fragrant purple tree, with a crystal pool before us, gleaming like molten ruby in the light of the scarlet sky, I told her quite simply that I loved her--that I had known her always, and loved her as long. "The white chieftain of my dreams," she whispered, "for what long years I have wished for you to come and tell me that!" There was no need for further words between us. It was a long, long time before we returned to the machine, and then I am afraid we both flushed a little before the smile of tender understanding on Sam's lean face. CHAPTER XXV The Tragedy in the Purple Wood Our woodland life was happy. We were quite unconscious of the events that were shaping themselves to bring sudden catastrophe. We saw in our simple lives no foreshadowing of the supreme moments of the stupendous drama in which we were involved. The crisis came with little enough warning. On the last day of our joyous existence there (we had fallen into the habit of making an arbitrary division of our time into days and nights), Sam arose and fixed our breakfast. I remember that we had pancakes, with maple sirup. Then, since "Alexander" was fluttering about, eager for the day's hunt, and flickering messages to him with its petal-like membrane, he got his rifle and they departed.