Sam, clad in a pair of greasy overalls, with a great smudge of grease already over half his lean face, was working intently over a huge complex device in the center of the room. Evidently it had been recently and hastily assembled from the materials at hand, and was not yet quite finished. In fact, a desk by the wall was still littered with the plans and calculations from which it had been set up. It was evidently founded on an adaptation of Sam's great invention of forty years before, the hydrodyne sub-atomic engine. The hydrodyne is based in principle on the catacytic disruption, by means of a radioactive salt, of water, the products being hydrogen and oxygen gases, which are burned in the cylinders, the steam formed being condensed and pumped back into the coils. The actual energy comes from the disintegration of hydrogen atoms, and the efficiency of the device is shown by the fact that the great generators on the transoceanic aerial liners require only a half pint of water as fuel per trip. At one end of Sam's new machine was the hydrodyne unit. From the size of the catalyzer coil, it must have been of vast capacity. The conduits led to the transformer coils, and above the coils were the giant electron tubes, six feet high, of a novel, horseshoe shape. Sam was working with deft fingers at the connections. "It will be hours, yet," he said absently, without looking up. For a long time I stood looking at him, as he worked with utter absorption and feverish haste. There was nothing I could do to help him--I could hardly understand what he was about. How strange it was to stand there in a freezing world and watch one lone man struggling to save it! [Illustration: _For a long time I stood looking at him, as he worked with utter absorption and feverish haste.... How strange it was to stand and watch one lone man in a freezing world struggling to save it!_] The cold rain was drumming heavily on the roof, and the roar of the sea had risen. The wind was blowing a gale, but there was no lightning in the storm that night. The out-of-doors was as dark as Erebus. Presently it grew cold in the room. I went out and shut the doors, and turned on the resistance heaters. Then I made a cup of coffee and brought it to Sam. He gulped it down absently, and went on without a word. I went back to my chair by the wall, and I think I must have fallen asleep. CHAPTER V The Etheric Storm The next thing I knew, Sam was shaking my shoulder. I sat up, rubbing my eyes, a bit dazed at first, and uncertain whether I could credit what I remembered to be a vivid nightmare. But when I looked at the utter fatigue and the intense anxiety on the old scientist's face, I knew that it was not a dream. "I've got it adjusted now," he said. "Suppose you go outside and watch. We need to know exactly what happens. And it may fail."