class="initial">They were clothed in some coarse, black stuff that bristled as though loosely woven of stiff hair, and yet which was not a true fabric, for it seemed to move within itself, and scintillate, as though composed of billions of restless motes. And as the strange creatures closed in quickly, I saw that theirs was not solid flesh, but, like the clothing that partially covered them, an attenuated substance that was not quite real.

Have you ever sat close to the screen in a motion picture theatre, so that the graininess of the moving film was visible? These creatures were like such shadows, seen in three dimensions.

I retreated two or three swift steps, jerking the revolver from my pocket.

“Back!” I warned, hoping they would understand the tone of voice if not the words. “Back—or I’ll pot a couple of you!”

They glanced at each other, swiftly, almost as though they understood. It seemed to me that their mouths lifted; that they almost smiled. Then they rushed at me.

I had only one box of cartridges, besides those in the cylinder of my gun. I didn’t know what might be in store for me, and I took no chances.

My first shot sent one of the creatures spinning to the ground. Two more were almost upon me before I could level the weapon and pull the trigger again. I got them both.

The rest of that unholy crew were grinning, and their eyes were shining with anticipation. They closed in upon me eagerly, each apparently doing everything in his power to invite my attention. It was bewildering, and I watched them warily, suspecting a trick. There were only three more cartridges left in my gun, and I did not dare replace the fired shells for fear they would rush me when the action was open and the gun momentarily useless.

I was just about to risk one more cartridge when another figure materialized in the ranks of the enemy; a taller, commanding figure, with a shining jewel, perhaps a mark of authority, dangling from his corded brown throat.

The others fell back instantly, and the newcomer approached me swiftly, holding out his hands as though in supplication.

So I was to receive a cordial welcome after all! I breathed a sigh of relief, and pocketed the weapon—and instantly the dark eyes flashed angrily. I held out both hands, to show that they were empty, trying to express my willingness to be friends.

He hesitated, and then uttered a high-pitched sound that I presumed to be a word of command. Before I could free the gun again, the creatures had me, and while their flesh looked more unnatural and unreal than ever, at close range, their long fingers gripped me like talons of steel. The being which had uttered the command disappeared, and my captors led me, struggling and protesting, toward the black, ugly towers of the city.

Over the barren, rocky ground we hurried; past the wretched hovels on the outskirts of the city, and through crooked, dismal streets, toward the center of the city.

A great crowd of creatures similar to my captors hemmed us in. Before us, they thinned into nothingness as we approached, only to swarm into being in some other spot. It was terrifying; an unbelievable experience that made me question my sanity. The only vestige of comfort left me was the hope that they were taking me to Hope and Vic.

At the entrance of one of the huge misshapen black buildings, the creature with the brilliant stone at his throat appeared as suddenly as a light flashes up in the darkness. With him were two others, each wearing a similar jewel of authority. They stood aside for us to enter, and then followed us down a long corridor which was not lighted by any device I could discern, and yet which was not dark.

A broad door swung open, and I was thrust through the doorway.

“Pete!” shouted a familiar voice, and I scrambled to my feet. There was Vic, his red hair tousled, and his face gray with worry. Behind him, her big blue eyes brimming, her lips quivering, was Hope.

“Vic! Well, here I am. And Hope, dear....”

My voice trailed off. These were not Vic and Hope before me; they were unreal creatures, like the beings which had captured me. I could recognize the face and the figure of the woman I loved and of her brother; but they seemed to have no substance.

Hope suddenly put her arms about me. She was sobbing.

“Don’t, Peter!” she whispered.

“Don’t look at me like that. I know how you feel. You—you and Vic—you aren’t real to me, either! We’re just shadows—lost souls....”

“Buck up, Hope!” Vic’s voice was kindly, yet firm and gravely commanding. “We’re all right. Only—temporarily—we’re Infra-Medians. Sit down, Pete, and let’s talk. It may be that there’s no time to lose in making some plans.”

First of all,” I insisted, “tell me where we are; what’s happened to us. Do you know?”

“Where we are? Surely. Looking at it in one way, we’re less than a mile from my laboratory.”

“But, Vic!” I protested. “Do you really mean that we’re less than a mile from your laboratory; from our own world? If we were, we could see it; we’d bump into our own trees and houses and people; we’d be knocked down by automobiles, and—”

“Two bodies cannot occupy the same space at the same time. Old law of simple physics. Is that what you mean?” interrupted Vic.

“Why, yes.”

“And a body; what’s that?”

“A body? Why, matter, I suppose.”

“And matter is what?”

“Anything that occupies space,” I replied triumphantly. I had remembered that much from my physics classes.

“True,” smiled Vic. “But let’s see. It is possible to have sound and light in the same place, isn’t it? We can even add other things: heat and electricity, for example. Speaking of electricity, a tremendous current of it adds nothing to the weight of the wire carrying it, and nothing to its bulk, unless we have a heating overload. Current enough to kill a thousand men, or to do the work of a million horses, weighs nothing, is invisible, and actually does nothing until released in some form or other, either by accident or design.”

“True, but electricity isn’t matter. Our old world is matter; I’m matter, and you’re matter. Why don’t we bump into things?”

“Our old world is matter, true enough, but for the rest, you’re wrong, Pete, old son. You’re not matter, any more. You’re something else. In terms of our own being, you do not exist in your present form. This world does not exist. And the reverse is just as true.”

I stared at him, bewildered.

“What am I, then—a ghost?”

“Nothing of the sort. You’re old Pete Grahame, a darned good half-back, and the world’s rottenest scientist. Only you’ve been passed into another form of being, through the action of four little quartz bulbs whose periods of vibrations form a beat—but that’s over your head, Pete, old son, and we’ll have time to talk over details when we get back. Right now, we’re in somewhat of a jam.” Instinctively, he glanced at Hope; it was her danger, and not his own, that had brought that haggard pallor to his face in so short a time.

“That’s what I don’t understand. What do these people—if you can call them that—want of us?”

Vic looked down, frowning.

“I’m not sure I’m right,” he replied after a moment, “but if I am—they wish us to kill them. As many as possible.

“When I found myself here, I wandered nearly to the city before I was molested. When they did appear, and tried to lay hands on me, I warned them back, and finally shot one of them.

“The effect was magical. They seemed unable