The subject being one of paramount interest, it was a matter of minutes until the full complement of two hundred men and women were in the main saloon, clinging to hastily rigged hand lines, closely packed before the raised platform upon which were King and Czuv, wired together with the peculiar Callistonian harness. To most of the passengers, familiar with the humanity of three planets, the appearance of the stranger brought no surprise; but many of them stared in undisguised amazement at his childish body, his pale, almost colorless skin, his small, weak legs and arms, and his massive head.
"Ladies and gentlemen!" Captain King opened the meeting. "I introduce to you Captain Czuv, of the scout cruiser Bzarvk, of the only human race now living upon the fourth large satellite of Jupiter, which satellite we know as Callisto. I am avoiding their own names as much as possible, because they are almost unpronounceable in English or Interplanetarian. This device that you see connecting us is a Callistonian thought transformer, by means of which any two intelligent beings can converse without language. Our situation is peculiar, and in order that you may understand fully what lies ahead of us, the captain will now speak to you, through me—that is, what follows will be spoken by Captain Czuv, of the Bzarvk, but he will be using my vocal organs."
"Friends from distant Tellus," King's voice went on, almost without a break, "I greet you. I am glad, for your sake as well as our own, that your vessel was able to destroy the hexan ship holding you captive, and whose crew would have killed you all as soon as they had landed your vessel and had read your minds. I regret bitterly that we can do so little for you, for only the representatives of a human civilization being exterminated by a race of highly intelligent monsters can fully realize how desirable it is for all the various races of humanity to assist and support each other. In order that you may understand the situation, it is necessary that I delve at some length into ancient history, but we have ample time. In about ..." he broke off, realizing that the two races had no thought in common in the measure of time.
"One-half time of rotation of Great Planet upon axis?" flashed from Czuv's brain, and "About five hours," King's mind flashed back.
"It will be about five hours before any steps can be taken, so that I feel justified in using a brief period for explanation. In the evolution of the various forms of life upon Callisto, two genera developed intelligence far ahead of all others. One genus was the human, as you and I; the other the hexan. This creature, happily unknown to you of the planets nearer our common sun, is the product of an entirely different evolution. It is a six-limbed animal, with a brain equal to our own—one perhaps in some ways superior to our own. They have nothing in common with humanity, however; they have few of our traits and fewer of our mental processes. Even we who have fought them so long can scarcely comprehend the chambers of horror that are their minds. Even were I able to paint a sufficiently vivid picture with words, you of Earth could not begin to understand their utter ruthlessness and inhumanity, even among themselves. You would believe that I was lying, or that my viewpoint was warped. I can say only that I hope most sincerely that none of you will ever get better acquainted with them."
"Ages ago, then, the human and the hexan developed upon all four of the major satellites of the Great Planet, which you know as Jupiter, and upon the north polar region of Jupiter itself. By what means the two races came into being upon worlds so widely separated in space we know not—we only know it to be the fact. Human life, however, could not long endure upon Jupiter. The various human races, after many attempts to meet conditions of life there by variations in type fell before the hexans; who, although very small in size upon the planet, thrived there amazingly. Upon the three outer satellites humanity triumphed, and many hundreds of cycles ago the hexans of those satellites were wiped out, save for an occasional tribe of savages of low intelligence who lived in various undesirable portions of the three worlds. For ages then there was peace upon Callisto. Here is the picture at that time—upon Jupiter the hexans; upon Io hexans and humans, waging a ceaseless and relentless war of mutual extermination; upon the three outer satellites humanity in undisturbed and unthreatened peace. Five worlds, each ignorant of life upon any other.
"As I have said, the hexans of Jupiter were, and are, diabolically intelligent. Driven probably by their desire to see what lay beyond their atmosphere of eternal cloud, to the penetration of which their eyesight was attuned, they developed the space-ship; and effected a safe landing, first upon the barren, airless moonlet nearest them, and then upon fruitful Io. There they made common cause with the hexans against the humans, and in space of time Ionian humanity ceased to exist. Much traffic and interbreeding followed between the hexans of Jupiter and those of Io, resulting in time in a race intermediate in size between the parent stocks and equally at home in the widely variant air pressures and gravities of planet and satellite. Soon their astronomical instruments revealed the cities of Europa to their gaze, and as soon as they discovered that the civilization of Europa was human, they destroyed it utterly, with the insatiable blood lust that is their heritage.
"In the meantime the human civilizations of Ganymede and Callisto had also developed instruments of power. Observing the cities upon the other satellites, many scientists studied intensively the problem of space navigation, and finally there was some commerce between the two outer satellites at favorable times. Finally, vessels were also sent to Io and to Europa, but none of them returned. Knowing then what to expect, Ganymede and Callisto joined forces and prepared for war. But our science, so long attuned to the arts of peace, had fallen behind lamentably in the devising of more and ever more deadly instruments of destruction. Ganymede fell, and in her fall we read our own doom. Abandoning our cities, we built anew underground. Profiting from lessons learned full bloodily upon Ganymede, we resolved to prolong the existence of the human race as long as possible.
"The hexans were, and are masters of the physical science. They command the spectrum in a way undreamed of. Their detectors reveal etheric disturbances at unbelievable distances, and they have at their beck and call forces of staggering magnitude. Therefore in our cities is no electricity save that which is wired, shielded, and grounded; no broadcast radio; no source whatever of etheric disturbances save light—and our walls are fields of force which we believe to be impenetrable to any searching frequency capable of being generated. Now I am able to picture to you the present.
"We are the last representatives of the human race in the Jovian planetary system. Our every trace upon the surface has been obliterated. We are hiding in our holes in the ground, coming out at night by stealth so that our burrows shall not be revealed to the hexans. We are fighting for time in which our scientists may learn the secrets of power—and fearing, each new day, that the enemy may have so perfected their systems of rays that they will be able to detect us and destroy us, even in our underground and heavily shielded retreats, by means of forces even more incomprehensible than those they are now employing.