The old man stood erect in the opening, with a hand upon his thoughtful brow. "I don't know," he said. "I didn't think they could come. They must have mastered secrets of time and space that we know nothing of. They have conquered our limitations of distance. They must be ages ahead of us!" "But the house--it just melted away!" "As for that, the emanations of the green cloud must have disrupted the atoms, allowing the electrons to fall together to make neutrons (formed of united protons and electrons) so small that they fell through the ground, toward the center of the earth. That is easy enough to understand--in fact, I could probably have developed a similar ray myself, as a result of my work on the hydrodyne. The strange thing is how they got here!" "The thing just seemed to appear and vanish!" "Possibly we could see it only when it was lit with the radiation of the green. It may have just slipped up and away in the darkness. But it is more likely--judging from the etheric disturbance it created--that it did not come through our space at all, but moved by the distortion of hyper-space--came through the fourth dimension, in effect!" "And they seemed to know just where to strike!" "Yes. They must have found that by triangulation on my interference waves I was doing the same trick for them when the apparatus warned me." "You were what?" "I have been working a long time to get the direction of that mysterious force." "And you succeeded!" "You remember the Mangar Deep?" "What? Oh, yes. Discovered in the South Pacific by Mangar and Kane about 1945." "In 1946, I believe. The disturbance comes from there. _It emanates from a point ten miles below the level of the Pacific!_" "What! Impossible!" "Do I make mistakes?" Sam asked softly. "No. But the discoverers reported only six miles of water. And anyhow, men couldn't live under there!" "The exact spot is somewhat south of their soundings. But, Mel, don't assume that we have to deal with men! We may be dealing with entities that developed in the sea, even with creatures of the rocks below the sea! I tell you, it's outside the range of your old anthropomorphic fiction!" I could say nothing more. I sat still, with rather unpleasant thoughts. Intelligences that could reach casually from a point ten miles below sea level, to wipe out a building ten thousand miles away! Such things are very good in amazing romances, but extremely hard to face squarely in real life! For many minutes Sam was silent. He had pulled out his battered pipe and filled it absently with illegal tobacco. He stood puffing on it steadily, with the dim glow coming and going on his tanned face as he drew. Presently he spoke very softly: "Mel, we can go in the Omnimobile to see about it." "Dive into the Deep!" "We could do it." "Ten miles of water! Good Lord! That would crush us like--like--" "I think the machine would stand it." "But what could we do?" "We don't know until we know what needs to be done."