"Their thoughts are not our thoughts, their ideals not our ideals. Perhaps they have nothing in common with us except the primal basis of all life, self-preservation, the necessity of feeding. "Maybe they have come of their own will. I prefer to believe that they have. Perhaps they are merely following the natural course of events, obeying some immutable law legislated by some higher being who watches over the cosmos and dictates what shall be and what shall not be. If this is true it means that there has been a flaw in my reasoning, for I believed that the life of each plane degenerated in company with the degeneration of its plane of existence, which would obey the same evolutional laws which govern the life upon it. I am quite satisfied that this invasion is a well-planned campaign, that some fourth-dimensional race has found a means of breaking through the veil of force which separates its plane from ours." "But," pointed out Henry Woods, "you say they are fourth-dimensional things. I can't see anything about them to suggest an additional dimension. They are plainly three-dimensional." "Of course they are three-dimensional. They would have to be to live in this world of three dimensions. The only two-dimensional objects which we know of in this world are merely illusions, projections of the third dimension, like a shadow. It is impossible for more than one dimension to live on any single plane. "To attack us they would have to lose one dimension. This they have evidently done. You can see how utterly ridiculous it would be for you to try to attack a two-dimensional thing. So far as you were concerned it would have no mass. The same is true of the other dimensions. Similarly a being of a lesser plane could not harm an inhabitant of a higher plane. It is apparent that while the Horror has lost one material dimension, it has retained certain fourth-dimensional properties which make it invulnerable to the forces at the command of our plane." The newspaperman was now sitting on the edge of his chair. "But," he asked breathlessly, "it all sounds so hopeless. What can be done about it?" Dr. White hitched his chair closer and his fingers closed with a fierce grasp upon the other's knee. A militant boom came into his voice. "My boy," he said, "we are to strike back. We are going to invade the fourth-dimensional plane of these hellhounds. We are going to make them feel our strength. We are going to strike back." Henry Woods sprang to his feet. "How?" he shouted. "Have you...?" Dr. White nodded. "I have found a way to send the third-dimensional into the fourth. Come and I will show you." * * * * *