His first effort at movement brought realization that he was in the grip of a strange paralysis. His head and neck seemed quite normal in every way, but from the throat downward his body was completely dead as far as any power of voluntary movement was concerned.

He twisted his head stiffly to one side, and saw that Helen was standing there beside him. Just beyond her was the motionless figure of Gil Mapes. Both the gangster and the girl were in the grip of the same strange paralysis. Like Blake, they were standing there rigidly motionless, facing the gold-flecked barrier wall just in front of them.

A moment's painful scrutiny of their position showed Blake that the posts forming the wall of the enclosure at the end toward the cone had been brought in nearly a hundred yards toward them while they slept. The shimmering barrier sheet was now scarcely a yard from their faces, yet they still stood near the thicket where they had battled the headless horrors. Blake saw his coat half-buried in the blue-gray dust near his feet where Helen had discarded the garment to minister to Mapes.

Their unseen captor had obviously made definite preparations for whatever his next purpose with them was to be, for a long wheeled platform had been brought to a position opposite them just outside the shimmering gold-flecked sheet. Blake noted the shattered remains of Mapes' pistol on the ground at one side of the platform. It had apparently been fished from the enclosure and rendered harmless after their captor had seen the weapon's efficient use against the headless ape-things.

Cl.u.s.tered upon the wheeled platform was an a.s.semblage of intricately winding coils, glowing tubes, and other apparatus that conveyed no more meaning to Blake's bewildered gaze than a sight of the interior of a metropolitan power-house would to a Congo savage.

There was only one piece of the apparatus regarding whose probable function Blake could even guess. This was a pair of long slender arms that projected through the shimmering walls into the enclosure, supporting at their end a large thin metal plate located just over the heads of the three Earthlings. Blake was willing to wager that it was this overhead plate that was responsible for the odd paralysis that held them helpless.

Then a figure came slowly into view from where it had been concealed by the apparatus, and Blake forgot all thought of the strange mechanisms as he watched the monstrous thing clamber stiffly from the platform and halt squarely in front of the captives to stare at them through the transparency of the intervening force sheet.

The thing was a curious blending of human and b.e.s.t.i.a.l features. It stood barely five feet in height, yet its great scale-armored skull was at least three times as large as that of a grown man. There was colossal mental power and nameless evil glowing in the dark depths of the two abnormally large eyes that stared fixedly out from under the heavy forehead. The thing had no nose. The mouth opening, surrounded by a rosette of flabby gray skin, was a mere slit. The entire skull and face were covered with small, closely overlapping scales of l.u.s.terless gray.

The head merged directly into a short black torso nearly as wide as the skull itself. From this trunk there writhed a score of long black snake-like tentacles, each terminating in a flexible three-fingered "hand." The trunk was supported by two short thick legs, armored with gray scales, and ending in broad three-toed feet.

"Greetings, Earthlings!" The voice that emanated from the grotesque mouth was surprisingly resonant in tone. "Allow me to present myself. I am Zehru, imperial scientist of Xollar."

The monstrosity seemed amused at the expressions of blank surprise upon the faces of his captives. "I learned your crude language from your brain cells while you slept under the red ray," he explained. "Also I learned many other things regarding your planet, Earth. I am glad to find your world so well adapted to my purpose. Within a few years after my arrival there I shall be its unquestioned ruler."

Blake started to voice the many questions that were surging through his mind, but an imperious gesture of an outflung tentacle stopped him.

"Silence, Earthling!" There was tolerant contempt in Zehru's ringing voice. "I will explain some of the things that puzzle you. There is no reason why I should trouble myself to do so, yet it may while away the tedium of the short wait yet remaining before my apparatus becomes charged to the required point. Listen carefully, Earthling, for at best you will find many of my thoughts beyond the feeble limits of the word forms with which you have provided me.

"The world of Xollar, where you now are, is a planet in the island universe known to your astronomers as the Great Nebula of Andromeda.

Until a short time ago I was one of its ruling scientists. Then I sinned, and so grave was my sin according to the laws of this planet that the Council of Three decreed my death. That death sentence upon Xollar is irrevocable, and no man has yet escaped it no matter where upon the planet he may be when the appointed time for his execution comes. I was given the usual period of grace in which to put my affairs in order. Instead, I have labored unceasingly here in my laboratory, and my labors have borne fruit. I am the first man in Xollarian history to find a means of escaping the dread death penalty.

"Briefly, I discovered a way by which I can flee to your far-distant universe, where not even the powers of the Council of Three can follow me. That way lies through the door of inter-dimensional s.p.a.ce. In s.p.a.ce as you know it, the almost unthinkable distance of a million light years separates Xollar from the dwarf star you call your Sun. Yet, traveling _between_ s.p.a.ce, the two planets nearly touch each other. The same situation of being near neighbors in inter-dimensional s.p.a.ce holds true with Xollar and at least seven other planets located in widely separated parts of your universe.

"Let me try to ill.u.s.trate what I mean by traveling between s.p.a.ce. We will a.s.sume a nearly two-dimensional universe in the form of a circular piece of paper three feet in diameter. There is a dot in the exact center of each side of this paper. To a two-dimensional creature, forced to travel only on the surface of the paper, the distance between the two dots can never be less than thirty-six inches. Yet by cutting _between_ the two surfaces and going directly through the paper the dots are less than one-hundredth of an inch apart.

"Such is the case with Xollar and the planets in your universe which are our immediate neighbors in inter-dimensional s.p.a.ce. In order to reach those planets I had only to develop a method of using sufficient force to cut _between_ the three dimensions of intervening s.p.a.ce. In solving this problem I developed both an inter-dimensional net to bring beings from your universe to mine, and an inter-dimensional gate to permit beings to pa.s.s from here back to worlds in your galaxy.

"You have already seen the workings of the net. It was the device of green fire that brought you here. The use of the net was a vital part of my plans, for without the use of a physical body from some world in your universe I could not hope to live longer than a few minutes after leaving Xollar via the inter-dimensional gate. The inherent characteristics and basic elements of your galaxy and the Andromedan universe are so different in every way that an inhabitant of either star-group cannot exist in the other. Xollar's purple atmosphere is characteristic of Andromedan worlds. Your oxygen-saturated air is typical of worlds in your galaxy. Just as Xollar's purple mists would be immediately fatal to you, so would your clear oxygen-tainted air be quickly fatal to me.

"Accordingly, my only chance of surviving in one of your worlds is to first transfer my Intelligence to the body of one of the dwellers upon that planet. Of the seven planets within reach of my net I found only two that promised to be at all suitable. One was your Earth, the other a minor planet circling the star you call Vega. I brought both you and a net-load of Vegans here to this oxygen-filled enclosure I had already prepared.

"The Vegans were the headless things with the jelly nuclei. I watched your battle with them, and waited to choose as my vehicle the planetary type that proved the stronger. You vanquished the Vegans, so it is in the body of an Earthling that I shall leave Xollar, and it is to the planet Earth that I shall be hurtled through the inter-dimensional gate.

"Aside from the slight difficulty caused by having to keep my body and yours each in its proper element during the operation, the matter of transfer into one of your bodies is a simple one. It involves none of the clumsy brain surgery of your Earthly science. We of Xollar have found that the real Intelligence of a being is an invisible force not at all dependent for existence upon the protoplasm through which it manifests. My Intelligence can function quite as well in your brain cells as in my own.

"I require no a.s.sistant in the transfer." Zehru indicated an intricate piece of apparatus on the platform behind him. It was a ma.s.sive cylinder of fluorescent metal, with two long metallic cables running from its center, each cable ending in a saucer-shaped disk.

"I have only to thrust one cable through the force-wall into your enclosure and place its disk upon one of your heads, then place the other disk upon my own head. The apparatus is entirely automatic. Three seconds after both disks are in place my Intelligence will course into the Earthling brain, driving out his Intelligence and destroying it as mine enters.

"I will, of course, remove the selected body from under the paralyzing plate before I attach the disks. Then when I am safely transferred to the Earthling body I will have only to walk on through the enclosure to the silver arch at the far end and leave Xollar forever.

"That silver arch is the inter-dimensional gate to your Earth. Its operation is slightly different from that of the net. Where the net was capable of reaching under the surface of your planet, a proceeding I tried when two attempts upon the surface proved fruitless, the gate is so adjusted that it will place its pa.s.senger exactly upon the surface of your world. It requires no cooperation from this end. When I step under the arch I merely close a black lever there. Inter-dimensional force immediately catapults me to your Earth. Then the automatic mechanism of the gate will within half a minute of my departure release an explosion that will shatter everything within a radius of a mile here, and so prevent the Council of Three from even guessing the method of my escape."

"But what of the two of us whose bodies you do not need?" Blake protested. "Can you not at least take them through the arch-gate with you back to their home world?"

"Why should I do anything so foolish as that?" Zehru answered callously.

"They might easily be a menace to my first attempts to establish myself upon your planet. Far better to leave them here in their present state of paralysis to be safely destroyed in the explosion of the gate."

Zehru now thrust three of his tentacles into a vat of milky fluid, and withdrew them coated with a silver sheen on the black flesh. The silver glaze seemed to be an insulation against both the oxygen of the enclosure and the paralyzing force of the overhead disk, for the Xollarian promptly thrust the three silver-coated arms through the wall and began handling the bodies of Mapes and Blake in a painstaking process of examination.

Again Blake noted that the shimmering gold-flecked wall closed quickly in and kept its surface unbroken no matter how often objects were thrust through it.

Completely ignoring Helen, Zehru lifted first Mapes, then Blake, his tentacles probing, fingering, exploring. There was enormous power in the Xollarian's grotesque body. He lifted the men as though they were wooden dolls, bringing them close to the shimmering wall to peer at them, then setting them carefully down again on their feet under the disk. Blake wondered idly why their stiff bodies did not topple over when they were left unsupported, then decided that the paralyzing force of the disk probably left the automatic muscular balancing movements unimpaired, affecting only the powers of voluntary movement.

Then, as Zehru set him down after one of the periods of examination, Blake noticed a new and startling change the moment his feet touched the ground. His right leg and right arm were no longer dead!

He hurriedly glanced down at the ground at his feet, and promptly found what seemed to be the reason for his partial freedom from the paralysis.

In setting his body down the last time Zehru had moved Blake slightly.

His right foot now rested upon a corner of the discarded topcoat lying half-buried there in the blue-gray dust.

The heavily rubberized cloth apparently acted as an insulating sheet that prevented the effective grounding of the paralyzing force that streamed down through Blake's body from the overhead disk. Consequently all portions of his body between the coat and the disk were free from the paralysis. For a moment Blake wondered at Zehru's carelessness. Then he realized that the insulating qualities of rubber would naturally be unknown to a Xollarian.

Noting that Zehru was busy at the moment with his work upon Mapes, Blake quickly grasped at the faint chance the presence of the rubberized cloth offered him. Working with infinite slowness and caution, he edged his right foot over an inch at a time, dragging the rest of his body with it.

Luck was with him. Zehru continued, absorbed in his work upon Mapes. The Xollarian's telepathic powers apparently functioned only with the aid of the red ray, for he remained oblivious of Blake's actions. One final cautious dragging movement, and Blake's entire body was upon the cloth, with every muscle again vibrantly alive.

Blake stood there motionless, faking paralysis, while his brain raced in an effort to figure the best use to make of his present advantage. He was still trapped, not daring to reach even a hand beyond the protection of the cloth underfoot. The first essential of any effort at escape would have to be a lunge of sufficient power to take him safely beyond the area of the disk's influence.

Blake's first thought was to hurl himself through the barrier wall upon Zehru, trusting to sheer surprise to overwhelm the Xollarian, but he quickly dismissed that plan. It left too many elements in Zehru's favor.

There was a tube-like weapon thrust in a belt around Zehru's middle and there were probably a dozen other different weapons lying handy to his reach among the apparatus on the platform. The deadly purple mists beyond the wall would alone in all probability overcome Blake before he could batter Zehru down.

By far the best plan was to stage the battle inside the enclosure where Blake would be in his own native element. If he could yank Zehru inside the wall he would have him away from contact with his mechanical weapons and battling in an atmosphere inherently poisonous to him. Under those circ.u.mstances, Blake felt that he might have an even chance in a hand-to-hand combat with the powerful but slow-footed Xollarian.

Once Zehru was eliminated, escape back to Earth should be a simple matter. The silver gate, with its automatic mechanism needing only the closing of a lever, was ready and waiting there in the enclosure behind them.