"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 Space. In Space 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 Space, the two planets nearly touch each other. The same situation of being near neighbors in inter-dimensional Space holds true with Xollar and at least seven other planets located in widely separated parts of your universe.
"Let me try to illustrate what I mean by traveling between Space. We will assume 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 Space. 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 Space. 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 pass 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.