The paper had gone to press, graphically describing the latest of the many horrible events which had been enacted upon the Earth in the last six months. The headlines screamed that Six Corners, a little hamlet in Pennsylvania, had been wiped out by the Horror. Another front-page story told of a Terror in the Amazon Valley which had sent the natives down the river in babbling fear. Other stories told of deaths here and there, all attributable to the “Black Horror,” as it was called.

The telephone rang.

“Hello,” said the editor.

“London calling,” came the voice of the operator.

“All right,” replied the editor.

He recognized the voice of Terry Masters, special correspondent. His voice came clearly over the transatlantic telephone.

“The Horror is attacking London in force,” he said. “There are thousands of them and they have completely surrounded the city. All roads are blocked. The government declared the city under martial rule a quarter of an hour ago and efforts are being made to prepare for resistance against the enemy.”

“Just a second,” the editor shouted into the transmitter.

He touched a button on his desk and in a moment an answering buzz told him he was in communication with the press-room.

“Stop the presses!” he yelled into the speaking tube. “Get ready for a new front make-up!”

“O.K.,” came faintly through the tube, and the editor turned back to the phone.

“Now let’s have it,” he said, and the voice at the London end of the wire droned on, telling the story that in another half hour was read by a world which shuddered in cold fear even as it scanned the glaring headlines.

“Woods,” said the editor of the Press to a reporter, “run over and talk to Dr. Silas White. He phoned me to send someone. Something about this Horror business.”

Henry Woods rose from his chair without a word and walked from the office. As he passed the wire machine it was tapping out, with a maddeningly methodical slowness, the story of the fall of London. Only half an hour before it had rapped forth the flashes concerning the attack on Paris and Berlin.

He passed out of the building into a street that was swarming with terrified humanity. Six months of terror, of numerous mysterious deaths, of villages blotted out, had set the world on edge. Now with London in possession of the Horror and Paris and Berlin fighting hopelessly for their lives, the entire population of the world was half insane with fright.

Exhorters on street corners enlarged upon the end of the world, asking that the people prepare for eternity, attributing the Horror to the act of a Supreme Being enraged with the wickedness of the Earth.

Expecting every moment an attack by the Horror, people left their work and gathered in the streets. Traffic, in places, had been blocked for hours and law and order were practically paralyzed. Commerce and transportation were disrupted as fright-ridden people fled from the larger cities, seeking doubtful hiding places in rural districts from the death that stalked the land.

A loudspeaker in front of a music store blared forth the latest news flashes.

“It has been learned,” came the measured tones of the announcer, “that all communication with Berlin ceased about ten minutes ago. At Paris all efforts to hold the Horror at bay have been futile. Explosives blow it apart, but have the same effect upon it as explosion has on gas. It flies apart and then reforms again, not always in the same shape as it was before. A new gas, one of the most deadly ever conceived by man, has failed to have any effect on the things. Electric guns and heat guns have absolutely no effect upon them.

“A news flash which has just come in from Rome says that a large number of the Horrors has been sighted north of that city by airmen. It seems they are attacking the capitals of the world first. Word comes from Washington that every known form of defense is being amassed at that city. New York is also preparing...”

Henry Woods fought his way through the crowd which milled in front of the loudspeaker. The hum of excitement was giving away to a silence, the silence of a stunned people, the fearful silence of a populace facing a presence it is unable to understand, an embattled world standing with useless weapons before an incomprehensible enemy.

In despair the reporter looked about for a taxi, but realized, with a groan of resignation, that no taxi could possibly operate in that crowded street. A street car, blocked by the stream of humanity which jostled and elbowed about it, stood still, a defeated thing.

Seemingly the only man with a definite purpose in that whirlpool of terror-stricken men and women, the newspaperman settled down to the serious business of battling his way through the swarming street.

“Before I go to the crux of the matter,” said Dr. Silas White, about half an hour later, “let us first review what we know of this so-called Horror. Suppose you tell me exactly what you know of it.”

Henry Woods shifted uneasily in his chair. Why didn’t the old fool get down to business? The chief would raise hell if this story didn’t make the regular edition. He stole a glance at his wrist-watch. There was still almost an hour left. Maybe he could manage it. If the old chap would only snap into it!

“I know no more,” he said, “than is common knowledge.”

The gimlet eyes of the old white-haired scientist regarded the newspaperman sharply.

“And that is?” he questioned.

There was no way out of it, thought Henry. He’d have to humor the old fellow.

“The Horror,” he replied, “appeared on Earth, so far as the knowledge of man is concerned, about six months ago.”

Dr. White nodded approvingly.

“You state the facts very aptly,” he said.

“How so?”

“When you say ‘so far as the knowledge of man is concerned.’”

“Why is that?”

“You will understand in due time. Please proceed.”

Vaguely the newspaperman wondered whether he was interviewing the scientist or the scientist interviewing him.

“They were first reported,” Woods said, “early this spring. At that time they wiped out a small village in the province of Quebec. All the inhabitants, except a few fugitives, were found dead, killed mysteriously and half eaten, as if by wild beasts. The fugitives were demented, babbling of black shapes that swept down out of the dark forest upon the little town in the small hours of the morning.

“The next that was heard of them was about a week later, when they struck in an isolated rural district in Poland, killing and feeding on the population of several farms. In the next week more villages were wiped out, in practically every country on the face of the Earth. From the hinterlands came tales of murder done at midnight, of men and women horribly mangled, of livestock slaughtered, of buildings crushed as if by some titanic force.

“At first they worked only at night and then, seeming to become bolder and more numerous, attacked in broad daylight.”

The newspaperman paused.

“Is that what you want?” he asked.

“That’s part of it,” replied Dr. White, “but that’s not all. What do these Horrors look like?”

“That’s more difficult,” said Henry. “They have been reported as every conceivable sort of monstrosity. Some are large and others are small. Some take the form of animals, others of birds and reptiles, and some are cast in appalling shapes such as might be snatched out of the horrid imagery of a thing which resided in a world entirely alien to our own.”

Dr. White rose from his chair and strode across the room to confront the other.

“Young man,” he asked, “do you think it possible the Horror might have come out of a world entirely alien to our own?”

“I don’t know,” replied Henry. “I know that some of the scientists believe they came from some other planet, perhaps even from some other solar system. I know they are like nothing ever known before on Earth. They are always inky black, something like black tar, you know, sort of sticky-looking, a disgusting sight. The weapons of mankind can’t affect them. Explosives are useless and so are projectiles. They wade through poison gas and fiery chemicals and seem to enjoy them. Elaborate electrical barriers have failed. Heat doesn’t make them turn a hair.”

“And you think they came from some other planet, perhaps some other solar system?”

“I don’t know what to think,” said Henry. “If they came out of space they must have come in some conveyance, and that would certainly have been sighted, picked up long before it arrived, by our astronomers. If they came in small conveyances, there must have been many of them. If they came in a single conveyance, it would be too large to escape detection. That is, unless--”

“Unless what?” snapped the scientist.

“Unless it traveled at the speed of light. Then it would have been invisible.”

“Not only invisible,” snorted the old man, “but non-existent.”

A question was on the tip of the newspaperman’s tongue, but before it could be asked the old man was speaking again, asking a question:

“Can you imagine a fourth dimension?”

“No, I can’t,” said Henry.

“Can you imagine a thing of only two dimensions?”

“Vaguely, yes.”

The scientist smote his palms together.

“Now we’re coming to it!” he exclaimed.

Henry Woods regarded the other narrowly. The old man must be turned. What did fourth and second dimensions have to do with the Horror?

“Do you know anything about evolution?” questioned the old man.

“I have a slight understanding of it. It is the process of upward growth, the stairs by which simple organisms climb to become more complex organisms.”

Dr. White grunted and asked still another question:

“Do you know anything about the theory of the exploding universe? Have you ever noted the tendency of the perfectly balanced to run amuck?”

The reporter rose slowly to his feet.

“Dr. White,” he said, “you phoned my paper you had a story for us. I came here to get it, but all you have done is ask me questions. If you can’t tell me what you want us to publish, I will say good-day.”

The doctor put forth a hand that shook slightly.

“Sit down, young man,” he said. “I don’t blame you for being impatient, but I will now come to my point.”

The newspaperman sat down again.

“I have developed a hypothesis,” said Dr. White, “and have conducted several experiments which seem to bear it out. I am staking my reputation upon the supposition that it is correct. Not only that, but I am also staking the lives of several brave men who believe implicitly in me and my theory. After all, I suppose it makes little difference, for if I fail the world is doomed, if I succeed it is saved from complete destruction.

“Have you ever thought that our evolutionists might be wrong, that evolution might be downward instead of upward? The theory of the exploding universe, the belief that all of creation is running down, being thrown off balance by the loss of energy, spurred onward by cosmic accidents which tend to disturb its equilibrium, to a time when it will run wild and space will be filled with swirling dust of disintegrated worlds, would bear out this contention.

“This does not apply to the human race. There is no question that our evolution is upward, that we have arisen from one-celled creatures wallowing in the slime of primal seas. Our case is probably paralleled by thousands of other intelligences on far-flung planets and island universes. These instances, however, running at cross purposes to the general evolutional trend of the entire cosmos, are mere flashes in the eventual course of cosmic evolution, comparing no more to eternity than a split second does to a million years.

“Taking these instances, then, as inconsequential, let us say that the trend of cosmic evolution is downward rather than upward, from complex units to simpler units rather than from simple units to more complex ones.

“Let us say that life and intelligence have degenerated. How would you say such a degeneration would take place? In just what way would it be manifested? What sort of transition would life pass through in passing from one stage to a lower one? Just what would be the nature of these stages?”

The scientist’s eyes glowed brightly as he bent forward in his chair. The newspaperman said simply: “I have no idea.”

“Man,” cried the old man, “can’t you see that it would be a matter of dimensions? From the fourth dimension to the third, from the third to the second, from the second to the first, from the first to a questionable existence or plane which is beyond our understanding or perhaps to oblivion and the end of life. Might not the fourth have evolved from a fifth, the fifth from a sixth, the sixth from a seventh, and so on to no one knows what multidimension?”

Dr. White paused to allow the other man to grasp the importance of his statements. Woods failed lamentably to do so.

“But what has this to do with the Horror?” he asked.

“Have you absolutely no imagination?” shouted the old man.

“Why, I suppose I have, but I seem to fail to understand.”

“We are facing an invasion of fourth-dimensional creatures,” the old man whispered, almost as if fearful to speak the words aloud. “We are being attacked by life which is one dimension above us in evolution. We are fighting, I tell you, a tribe of hellhounds out of the cosmos. They are unthinkably above us in the matter of intelligence. There is a chasm of knowledge between us so wide and so deep that it staggers the imagination. They regard us as mere animals, perhaps not even that. So far as they are concerned we are just fodder, something to be eaten as we eat vegetables and cereals or the flesh of domesticated animals. Perhaps they have watched us for years, watching life on the world increase, lapping their monstrous jowls over the fattening of the Earth. They have awaited the proper setting of the banquet table and now they are dining.

“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.”

The machine was huge, but it had an appearance of simple construction. A large rectangular block of what appeared to be a strange black metal was set on end and flanked on each side by two smaller ones. On the top of the large block was set a half-globe of a strange substance, somewhat, Henry thought, like frosted glass. On one side of the large cube was set a lever, a long glass panel, two vertical tubes and three clock-face indicators. The control board, it appeared, was relatively simple.

Beside the mass of the five rectangles, on the floor, was a large plate of transparent substance, ground to a concave surface, through which one could see an intricate tangle of wire mesh.

Hanging from the ceiling, directly above the one on the floor, was another concave disk, but this one had a far more pronounced curvature.

Wires connected the two disks and each in turn was connected to the rectangular machine.

“It is a matter of the proper utilization of two forces, electrical and gravitational,” proudly explained Dr. White. “Those two forces, properly used, warp the third-dimensional into the fourth. A reverse process is used to return the object to the third. The principle of the machine is--”

The old man was about to launch into a lengthy discussion, but Henry interrupted him. A glance at his watch had shown him press time was drawing perilously close.

“Just a second,” he said. “You propose to warp a third-dimensional being into a fourth dimension. How can a third-dimensional thing exist there? You said a short time ago that only a specified dimension could exist on one single plane.”

“You have missed my point,” snapped Dr. White. “I am not sending a third-dimensional thing to a fourth dimension. I am changing the third-dimensional being into a fourth-dimensional being. I add a dimension, and automatically the being exists on a different plane. I am reversing evolution. This third dimension we now exist on evolved, millions of eons ago, from a fourth dimension. I am sending a lesser entity back over those millions of eons to a plane similar to one upon which his ancestors lived inconceivably long ago.”

“But, man, how do you know you can do it?”

The doctor’s eyes gleamed and his fingers reached out to press a bell.

A servant appeared almost at once.

“Bring me a dog,” snapped the old man. The servant disappeared.

“Young man,” said Dr. White, “I am going to show you how I know I can do it. I have done it before, now I am going to do it for you. I have sent dogs and cats back to the fourth dimension and returned them safely to this room. I can do the same with men.”

The servant reappeared, carrying in his arms a small dog. The doctor stepped to the control board of his strange machine.

“All right, George,” he said.

The servant had evidently worked with the old man enough to know what was expected of him. He stepped close to the floor disk and waited. The dog whined softly, sensing that all was not exactly right.

The old scientist slowly shoved the lever toward the right, and as he did so a faint hum filled the room, rising to a stupendous roar as he advanced the lever. From both floor disk and upper disk leaped strange cones of blue light, which met midway to form an hour-glass shape of brilliance.

The light did not waver or sparkle. It did not glow. It seemed hard and brittle, like straight bars of force. The newspaperman, gazing with awe upon it, felt that terrific force was there. What had the old man said? Warp a third-dimensional being into another dimension! That would take force!

As he watched, petrified by the spectacle, the servant stepped forward and, with a flip, tossed the little dog into the blue light. The animal could be discerned for a moment through the light and then it disappeared.

“Look in the globe!” shouted the old man; and Henry jerked his eyes from the column of light to the half-globe atop the machine.

He gasped. In the globe, deep within its milky center, glowed a picture that made his brain reel as he looked upon it. It was a scene such as no man could have imagined unaided. It was a horribly distorted projection of an eccentric landscape, a landscape hardly analogous to anything on Earth.

“That’s the fourth dimension, sir,” said the servant.

“That’s not the fourth dimension,” the old man corrected him. “That’s a third-dimensional impression of the fourth dimension. It is no more the fourth dimension than a shadow is three-dimensional. It, like a shadow, is merely a projection. It gives us a glimpse of what the fourth plane is like. It is a shadow of that plane.”

Slowly a dark blotch began to grow in the landscape. Slowly it assumed definite form. It puzzled the reporter. It looked familiar. He could have sworn he had seen it somewhere before. It was alive, for it had moved.

“That, sir, is the dog,” George volunteered.

“That was the dog,” Dr. White again corrected him. “God knows what it is now.”

He turned to the newspaperman.

“Have you seen enough?” he demanded.

Henry nodded.

The other slowly began to return the lever to its original position. The roaring subsided, the light faded, the projection in the half-globe grew fainter.

“How are you going to use it?” asked the newspaperman.

“I have ninety-eight men who have agreed to be projected into the fourth dimension to seek out the entities that are attacking us and attack them in turn. I shall send them out in an hour.”

“Where is there a phone?” asked the newspaperman.

“In the next room,” replied Dr. White.

As the reporter dashed out of the door, the light faded entirely from between the two disks and on the lower one a little dog crouched, quivering, softly whimpering.

The old man stepped from the controls and approached the disk. He scooped the little animal from where it lay into his arms and patted the silky head.

“Good dog,” he murmured; and the creature snuggled close to him, comforted, already forgetting that horrible place from which it had just returned.

“Is everything ready, George?” asked the old man.

“Yes, sir,” replied the servant. “The men are all ready, even anxious to go. If you ask me, sir, they are a tough lot.”

“They are as brave a group of men as ever graced the Earth,” replied the scientist gently. “They are adventurers, every one of whom has faced danger and will not shrink from it. They are born fighters. My one regret is that I have not been able to secure more like them. A thousand men such as they should be able to conquer any opponent. It was impossible. The others were poor soft fools. They laughed in my face. They thought I was an old fool--I, the man who alone stands between them and utter destruction.”

His voice had risen to almost a scream, but it again sank to a normal tone.

“I may be sending ninety-eight brave men to instant death. I hope not.”

“You can always jerk them back, sir,” suggested George.

“Maybe I can, maybe not,” murmured the old man.

Henry Woods appeared in the doorway.

“When do we start?” he asked.

“We?” exclaimed the scientist.

“Certainly, you don’t believe you’re going to leave me out of this. Why, man, it’s the greatest story of all time. I’m going as special war correspondent.”

“They believed it? They are going to publish it?” cried the old man, clutching at the newspaperman’s sleeve.

“Well, the editor was skeptical at first, but after I swore on all sorts of oaths it was true, he ate it up. Maybe you think that story didn’t stop the presses!”

“I didn’t expect them to. I just took a chance. I thought they, too, would laugh at me.”

“But when do we start?” persisted Henry.

“You are really in earnest? You really want to go?” asked the old man, unbelievingly.

“I am going. Try to stop me.”

Dr. White glanced at his watch.

“We will start in exactly thirty-four minutes,” he said.

“Ten seconds to go.” George, standing with watch in hand, spoke in a precise manner, the very crispness of his words betraying the excitement under which he labored.

The blue light, hissing, drove from disk to disk; the room thundered with the roar of the machine, before which stood Dr. White, his hand on the lever, his eyes glued on the instruments before him.

In a line stood the men who were to fling themselves into the light to be warped into another dimension, there to seek out and fight an unknown enemy. The line was headed by a tall man with hands like hams, with a weather-beaten face and a wild mop of hair. Behind him stood a belligerent little cockney. Henry Woods stood fifth in line. They were a motley lot, adventurers every one of them, and some were obviously afraid as they stood before that column of light, with only a few seconds of the third dimension left to them. They had answered a weird advertisement, and had but a limited idea of what they were about to do. Grimly, though, they accepted it as a job, a bizarre job, but a job. They faced it as they had faced other equally dangerous, but less unusual, jobs.

“Five seconds,” snapped George.

The lever was all the way over now. The half-globe showed, within its milky interior, a hideously distorted landscape. The light had taken on a hard, brittle appearance and its hiss had risen to a scream. The machine thundered steadily with a suggestion of horrible power.

“Time up!”

The tall man stepped forward. His foot reached the disk; another step and he was bathed in the light, a third and he glimmered momentarily, then vanished. Close on his heels followed the little cockney.

With his nerves at almost a snapping point, Henry moved on behind the fourth man. He was horribly afraid, he wanted to break from the line and run, it didn’t matter where, any place to get away from that steady, steely light in front of him. He had seen three men step into it, glow for a second, and then disappear. A fourth man had placed his foot on the disk.

Cold sweat stood out on his brow. Like an automaton he placed one foot on the disk. The fourth man had already disappeared.

“Snap into it, pal,” growled the man behind.

Henry lifted the other foot, caught his toe on the edge of the disk and stumbled headlong into the column of light.

He was conscious of intense heat which was instantly followed by equally intense cold. For a moment his body seemed to be under enormous pressure, then it seemed to be expanding, flying apart, bursting, exploding...

He felt solid ground under his feet, and his eyes, snapping open, saw an alien land. It was a land of somber color, with great gray moors, and beetling black cliffs. There was something queer about it, an intangible quality that baffled him.

He looked about him, expecting to see his companions. He saw no one. He was absolutely alone in that desolate brooding land. Something dreadful had happened! Was he the only one to be safely transported from the third dimension? Had some horrible accident occurred? Was he alone?

Sudden panic seized him. If something had happened, if the others were not here, might it not be possible that the machine would not be able to bring him back to his own dimension? Was he doomed to remain marooned forever in this terrible plane?

He looked down at his body and gasped in dismay. It was not his body!

It was a grotesque caricature of a body, a horrible profane mass of flesh, like a phantasmagoric beast snatched from the dreams of a lunatic.

It was real, however. He felt it with his hands, but they were not hands. They were something like hands; they served the same purpose that hands served in the third dimension. He was, he realized, a being of the fourth dimension, but in his fourth-dimensional brain still clung hard-fighting remnants of that faithful old third-dimensional brain. He could not, as yet, see with fourth-dimensional eyes, think purely fourth-dimensional thoughts. He had not oriented himself as yet to this new plane of existence. He was seeing the fourth dimension through the blurred lenses of millions of eons of third-dimensional existence. He was seeing it much more clearly than he had seen it in the half-globe atop the machine in Dr. White’s laboratory, but he would not see it clearly until every vestige of the third dimension was wiped from him. That, he knew, would come in time.

He felt his weird body with those things that served as hands, and he found, beneath his groping, unearthly fingers, great rolling muscles, powerful tendons, and hard, well-conditioned flesh. A sense of well-being surged through him and he growled like an animal, like an animal of that horrible fourth plane.