"I have thought of it at length. It is disgusting. Compelled to traffic with an alien form of life! Were it not to end in the extinction of those unspeakable hexans, it would be futile to the point of silliness.

I cannot understand them at all. There is ample room upon this planet for all of us. Our races combined are not using one seven-thousandth of its surface. You would think that they would shun all strangers.

Yet for ages have they attacked us, refusing to let us alone, until finally they forced us to prepare means for their destruction. They seem as senselessly savage as the jungle growths, and, but for their very evident intelligence, one would cla.s.s them as such. You would think that, being intelligent and being alien to us, they would not have anything to do with us in any way, peacefully or otherwise.

However, their intrusions and depredations are about to end."

"They certainly are. Vorkulia has endured much--too much--but I am glad that our forefathers did not decide to exterminate them sooner. If they had, we could not have been doing this now."

"There speaks the rashness of youth, Kromodeor. It is a violation of all our instincts to have any commerce with outsiders, as you will learn as soon as you see one of them. Then, too, we will lose heavily. Since we have studied their armaments so long, and have subjected every phase of the situation to statistical a.n.a.lysis, it is certain that we are to succeed--but you also know at what cost."

"Two-sevenths of our force, with a probable error of one in seven,"

replied the younger Vorkul. "And because that figure cannot be improved within the next seven years and because of the exceptional weakness of the hexans due to their unexpectedly great losses upon Callisto, we are attacking at this time. Their spherical vessels are nothing, of course.

It is in the reduction of the city that we will lose men and vessels.

But at that, each of us has five chances in seven of returning, which is good enough odds--much better than we had in that last expedition into the jungle. But by the Mighty Seven, I shall make myself wrap around one hexan, for my brother's sake," and his coils tightened unconsciously.

"Hideous, repulsive monstrosities! Creatures so horrible should not be allowed to live--they should have been tossed over the wall to the jungle ages ago!" Kromodeor curled out an eye as he spoke, and complacently surveyed the writhing cylinder of sinuous, supple power that was his own body.

"Better avoid contact work with them if possible," cautioned Wixill.

"You might not be able to unwrap, and to touch one of them is almost unthinkable. Speaking of wrapping, you know that they are putting on the finals of the contact work in the star this evening. Let's watch them."

They slid to the floor and wriggled away in perfect "step"--undulating along in such nice synchronism that their adjacent sides, only a few inches apart, formed two waving rigidly parallel lines. Deep in the lower part of the fortress they entered a large a.s.sembly room, provided with a raised platform in the center and having hundreds of short, upright posts in lieu of chairs; most of which were already taken by spectators. The two officers curled their tails comfortably around two of the vacant pillars, elevated their heads to a convenient level of sight and directed each an eye or two upon the stage. This was, of course, heptagonal. Its sides, like those of the mighty flying forts themselves, were not straight, but angled inward sufficiently to make the platform a seven-pointed star. The edge was outlined by a low rail, and bulwark and floor were padded with thick layers of a hard but smooth and yielding fabric.

In this star-shaped ring two young Vorkuls were contending for the championship of the fleet in a contest that seemed to combine most of the features of wrestling, boxing, and bar-room brawling, with no holds barred. Four hands of each of the creatures held heavy leather billies, and could be used only in striking with those weapons, the remaining hands being left free to employ as the owner saw fit. Since the sport was not intended to be lethal, however, the eyes and other highly vulnerable parts were protected by metal masks, and the wing ribs were similarly guarded by leathern shields. The guiding fins, being comparatively small and extremely tough, required no protection.

"We're just in time," Kromodeor whistled. "The main bout is nicely on.

See anyone from the flagship? I might stake a couple of korpels that Sintris will paint the symbol upon his wing."

"Most of their men seem to be across the star," Wixill replied, and both beings fell silent, absorbed in the struggle going on in the ring.

It was a contest well worth watching. Wing crashed against mighty wing and the lithe, hard bodies snapped and curled this way and that, almost faster than the eye could follow, in quest of advantageous holds. Above the shrieking wails of the crowd could be heard the smacks and thuds of the eight flying clubs as they struck against the leather shields or against tough and scaly hides. For minutes the conflict raged, with no advantage apparent. Now the fighters were flat upon the floor of the star, now dozens of feet in the air above it, as one or the other sought to gain a height from which to plunge downward upon his opponent; but both stayed upon or over the star--to leave its boundaries was to lose disgracefully.

Then, high in air, the visiting warrior thought that he saw an opening and grappled. Wings crashed in fierce blows, hands gripped and furiously wrenched. Two powerful bodies, tapering smoothly down to equally powerful tails, corkscrewed around each other viciously, winding up into something resembling tightly twisted lamp cord; and the two Vorkuls, each helpless, fell to the mat with a crash. Fast as was Zerexi, the gladiator from the flagship, Sintris was the merest trifle faster.

Like the straightening of a twisted spring of tempered steel that long body uncoiled as they struck the floor, and up under those shielding wings--an infinitesimal fraction of a second slow in interposing--that lithe tail sped. Two lightning loops flashed around the neck of the visitor and tightened inexorably. Desperately the victim fought to break that terrible strangle hold, but every maneuver was countered as soon as it was begun. Beating wings, under whose frightful blows the very air quivered, were met and parried by wings equally capable. Hands and clubs were of no avail against that corded cable of sinew, and Sintris, his head retracted between his wings and his own hands reenforcing that impregnable covering over his head and neck, threw all his power into his tail--tightening, with terrific, rippling surges, that already throttling band about the throat of his opponent. Only one result was possible. Soon Zerexi lay quiet, and a violet beam of light flared from a torch at the ringside, bathing both contenders. At the flash the winner disengaged himself from the loser, and stood by until the latter had recovered the use of his paralyzed muscles. The two combatants then touched wing tips in salute and flew away together, over the heads of the crowd; plunging into a doorway and disappearing as the two officers uncoiled from their "seats" and wriggled out into the corridor.

"Fine piece of contact work," said Wixill, thoughtfully. "I'm glad that Sintris won, but I did not expect him to win so easily. Zerexi shouldn't have gone into a knot so early against such a fast man."

"Oh, I don't know," argued Kromodeor. "His big mistake was in that second body check. If he had blocked the sixth arm with his fifth, taken out the fourth and second with his third, and then gone in with...." and so, quite like two early experts after a good boxing match, the friends argued the fine points of the contest long after they had reached their quarters.

Day after day the vast duplex cone of Vorkulian fortresses sped toward the north pole of the great planet, with a high and constant velocity. Day after day the complex geometrical figure in s.p.a.ce remained unchanged, no unit deviating measurably from its precise place in the formation. Over rapacious jungles, over geysers spouting hot water, over sullenly steaming rivers and seas, over boiling lakes of mud, and high over gigantic volcanoes, in uninterrupted eruptions of cataclysmic violence, the Vorkulian phalanx flew--straight north. The equatorial regions, considerably hotter than the poles, were traversed with practically no change in scenery--it was a world of steaming fog, of jungle, of hot water, of boiling, spurting mud, and of volcanoes.

Not of such mild and sporadic volcanic outbreaks as we of green Terra know, but of gigantic primordial volcanoes, in terrifyingly continuous performances of frightful intensity. Due north the Vorkulian spearhead was hurled, before the rigorous geometrical alignment was altered.

"All captains, attention!" Finally, in a high lat.i.tude, the flagship sent out final instructions. "The hexans have detected us and our long range observers report that they are coming to meet us in force. We will now go into the whirl, and proceed with the maneuvers exactly as they have been planned. Whirl!"

At the command, each vessel began to pursue a tortuous spiral path.

Each group of seven circled slowly about its own axis, as though each structure were attached rigidly to a radius rod, and at the same time spiraled around the line of advance in such fashion that the whole gigantic cone, wide open maw to the fore, seemed to be boring its way through the air.

"Lucky again!" Kromodeor, in the wardroom, turned to Wixill as the two prepared to take their respective watches. "It looks as though the first action would come while we're on duty. I've got just one favor to ask, if you have to economize on power, let Number One alone, will you?"

"No fear of that," Wixill hissed, with the Vorkulian equivalent of a chuckle. "We have abundance of power for all of your projector officers.

But don't waste any of it, or I'll cut you down five ratings!"

"You're welcome. When I shine old Number One on any hexan work, one flash is all we'll take. See you at supper," and, leaving his superior at the door of the power room, Kromodeor wriggled away to his station upon the parallel horizontal bars before his panel.

Making sure that his tail coils were so firmly clamped that no possible lurch or shock could throw him out of position, he set an eye toward each of his sighting screens, even though he knew that it would be long before those comparatively short range instruments would show anything except friendly vessels. Then, ready for any emergency, he scanned his one "live" screen--the one upon which were being flashed the pictures and reports secured by the high-powered instruments of the observers.

With the terrific acceleration employed by the hexan spheres, it was not long until the leading squadron of fighting globes neared the Vorkulian war-cone. This advance guard was composed of the new, high-acceleration vessels. Their crews, with the innate blood-l.u.s.t and savagery of their breed, had not even entertained the thought of accommodating their swifter pace to that of the main body of the fleet.

These vast, slow-moving structures were no more to be feared than those similar ones whose visits they had been repulsing for twenty long Jovian years--by the time the slower spheres could arrive upon the scene there would be nothing left for them to do. Therefore, few in number as were the vessels of the vanguard, they rushed to the attack. In one blinding salvo they launched their supposedly irresistible planes of force--dazzling, scintillating planes under whose fierce power the studying, questing, scouting fortresses previously encountered had fled back southward; cut, beaten, and crippled. These spiraling monsters, however, did not pause or waver in their stolidly ordered motion.

As the hexan planes of force flashed out, the dull green metal walls broke into a sparkling green radiance, against which the t.i.tanic bolts spent themselves in vain. Then there leaped out from the weird brilliance of the walls of the fortresses great shafts of pale green luminescence--tractor ray after gigantic tractor ray, which seized upon the hexan spheres and drew them ruthlessly into the yawning open end of that gigantic cone.

Then, in each group of seven, similar great streamers of energy reached out from fortress to fortress, until each group was welded into one mighty unit by twenty-one such bands of force. The unit formed, a ray from each of its seven component structures seized upon a designated sphere, and under the combined power of those seven tractors, the luckless globe was literally snapped into the center of ma.s.s of the Vorkulian unit There seven dully gleaming red pressor rays leaped upon it, backed by all the power of seven gigantic fortresses, held rigidly in formation by the unimaginable ma.s.s of the structures and by their twenty-one prodigious tractor beams. Under that awful impact, the screens and walls of the hexan spheres were exactly as effective as so many structures of the most tenuous vapor. The red glare of the vortex of those beams was lightened momentarily by a flash of brighter color, and through the foggy atmosphere there may have flamed briefly a drop or two of metal that was only liquefied. The red and green beams snapped out, the peculiar radiance died from the metal walls, and the gigantic duplex cone of the Vorkuls bored serenely northward--as little marked or affected by the episode as is a darting swift who, having snapped up a chance insect in full flight, darts on.

"Great Cat!" Far off in s.p.a.ce, Brandon turned from his visiray screen and wiped his brow. "Czuv certainly chirped it, Perce, when he called those things flying fortresses. But who, what, why, and how? We didn't see any apparatus that looked capable of generating or handling those beams--and of course, when they got started, their screens cut us off at the pockets. Wish we could have made some sense out of their language--like to know a few of their ideas--find out whether we can't get on terms with them some way or other. Funny-looking wampuses, but they've got real brains--their think-tanks are very evidently full of bubbles. If they have it in mind to take us on next, old son, it'll be just ... too ... bad!"

"And then some," agreed Stevens. "They've got something--no fooling. It looks like the hexans are going to get theirs, good and plenty, pretty soon--and then what? I'd give my left lung and four front teeth for one long look at their controls in action."

"You and me both--it's funny, the way those green ray-screens stick to the walls, instead of being spherical, as you'd expect ... should think they'd _have_ to radiate from a center, and so be spherical," Brandon cogitated. "However, we've got nothing corkscrewy enough to go through them, so we'll have to stand by. We'll stay inside whenever possible, look on from outside when we must, but all the time picking up whatever information we can. In the meantime, now that we've got our pa.s.sengers, old Doctor Westfall prescribes something that he says is good for what ails us. Distance--lots of distance, straight out from the sun--and I wouldn't wonder if we'd better take his prescription."

The two Terrestrial observers relapsed into silence, staring into their visiray plates, searching throughout the enormous volume of one of those great fortresses in another attempt to solve the mystery of the generation and propagation of the incredible manifestations of energy which they had just witnessed. Scarcely had the search begun, however, when the visirays were again cut off sharply--the rapidly advancing main fleet of the hexans had arrived and the scintillant Vorkulian screens were again in place.

True to hexan nature, training and tradition, the fleet, hundreds strong, rushed savagely to the attack. Above, below, and around the far-flung cone the furious globes dashed, attacking every Vorkulian craft viciously with every resource at their command; with every weapon known to their diabolically destructive race. Planes of force stabbed and slashed, concentrated beams of annihilation flared fiercely through the reeking atmosphere, gigantic aerial bombs and torpedoes were hurled with full radio control against the unwelcome visitor--with no effect.

Bound together in groups of seven by the mighty, pale-green bands of force, the Vorkulian units sailed calmly northward, spiraling along with not the slightest change in formation or velocity. The frightful planes and beams of immeasurable power simply spent themselves harmlessly against those sparklingly radiant green walls--seemingly as absorbent to energy as a sponge is to water, since the eye could not detect any change in the appearance of the screens, under even the fiercest blasts of the hexan projectors. Bombs, torpedoes, and all material projectiles were equally futile--they exploded harmlessly in the air far from their objectives, or disappeared at the touch of one of those dark, dull-red pressor rays. And swiftly, but calmly and methodically as at a Vorkulian practice drill, the heptagons were destroying the hexan fleet. Seven mighty green tractors would lash out, seize an attacking sphere, and snap it into the center of ma.s.s of the unit of seven. There would be a brief flash of dull red, a still briefer flare of incandescence, and the impalpable magnets would leap out to seize another of the doomed globes.

It was only a matter of moments until not a hexan vessel remained; and the Vorkulian juggernaut spiraled onward, now at full acceleration, toward the hexan stronghold dimly visible far ahead of them--a vast city built around Jupiter's northern pole.

At the controls of his projector, Kromodeor spun a dial with a many-fingered, flexible hand and spoke.

"Wixill, I am being watched again--I can feel very plainly that strange intelligence watching everything I do. Have the tracers located him?"

"No, they haven't been able to synchronize with his wave yet. Either he is using a most minute pencil or, what is more probable, he is on a frequency which we do not ordinarily use. However, I agree with you that it is not a malignant intelligence. All of us have felt it, and none of us senses enmity. Therefore, it is not a hexan--it may be one of those strange creatures of the satellites, who are, of course, perfectly harmless."

"Harmless, but unpleasant," returned Kromodeor. "When we get back I'm going to find his beam myself and send a discharge along it that will end his spying upon me. I do not...."

A wailing signal interrupted the conversation and every Vorkul in the vast fleet coiled even more tightly about his bars, for the real battle was about to begin. The city of the hexans lay before them, all her gigantic forces mustered to repel the first real invasion of her long and warlike history. Mile after mile it extended, an orderly labyrinth of spherical buildings arranged in vast interlocking series of concentric circles--a city of such size that only a small part of it was visible, even to the infra-red vision of the Vorkulians. Apparently the city was unprotected, having not even a wall. Outward from the low, rounded houses of the city's edge there reached a wide and verdant plain, which was separated from the jungle by a narrow moat of shimmering liquid--a liquid of such dire potency that across it, even those frightful growths could neither leap nor creep.

But as the Vorkulian phalanx approached--now shooting forward and upward with maximum acceleration, screaming bolts of energy flaming out for miles behind each heptagon as the full power of its generators was unleashed--it was made clear that the homeland of the hexans was far from unprotected. The verdant plain disappeared in a blast of radiance, revealing a transparent surface, through which could be seen ma.s.ses of machinery filling level below level, deep into the ground as far as the eye could reach; and from the bright liquid of the girdling moat there shot vertically upward a coruscantly refulgent band of intense yellow luminescence. These were the hexan defences, heretofore invulnerable and invincible. Against them any ordinary warcraft, equipped with ordinary weapons of offense, would have been as pitifully impotent as a naked baby attacking a battleship. But now those defenses were being challenged by no ordinary craft; it had taken the mightiest intellects of Vorkulia two long lifetimes to evolve the awful engine of destruction which was hurling itself forward and upward with an already terrific and constantly increasing speed.

Onward and upward flashed the gigantic duplex cone, its entire whirling ma.s.s laced and latticed together--into one mammoth unit by green tractor beams and red pressors. These tension and compression members, of unheard-of power, made of the whole fleet of three hundred forty-three fortresses a single stupendous structure--a structure with all the strength and symmetry of a cantilever truss! Straight through that wall of yellow vibrations the vast truss drove, green walls flaming blue defiance as the absorbers overloaded; its doubly braced tip rearing upward, into and beyond the vertical as it shot through that searing yellow wall. Simultaneously from each heptagon there flamed downward a green shaft of radiance, so that the whole immense circle of the cone's mouth was one solid tractor beam, fastening upon and holding in an unbreakable grip mile upon mile of the hexan earthworks.

Practically irresistible force and supposedly immovable object!

Every loose article in every heptagon had long since been stored in its individual shockproof compartment, and now every Vorkul coiled his entire body in fierce clasp about mighty horizontal bars: for the entire kinetic energy of the untold millions of tons of ma.s.s comprising the cone, at the terrific measure of its highest possible velocity, was to be hurled upon those unbreakable linkages of force which bound the trussed aggregation of Vorkulian fortresses to the deeply buried intrenchments of the hexans. The gigantic composite tractor beam snapped on and held. Inconceivably powerful as that beam was, it stretched a trifle under the incomprehensible momentum of those prodigious ma.s.ses of metal, almost halted in their terrific flight. But the war-cone was not quite halted; the calculations of the Vorkulian scientists had been accurate. No possible artificial structure, and but few natural ones--in practice maneuvers entire mountains had been lifted and hurled for miles through the air--could have withstood the incredible violence of that lunging, twisting, upheaving impact. Lifted bodily by that impalpable hawser of force and cruelly wrenched and twisted by its enormous couple of angular momentum, the hexan works came up out of the ground as a waterpipe comes up in the teeth of a power shovel. The ground trembled and rocked and boulders, fragments of concrete masonry, and ma.s.ses of metal flew in all directions as that city-encircling conduit of diabolical machinery was torn from its bed.

A portion of that conduit fully thirty miles in length was in the air, a twisted, flaming inferno of wrecked generators, exploding ammunition, and broken and short-circuited high-tension leads before the hexans could themselves cut it and thus save the remainder of their fortifications. With resounding crashes, the structure parted at the weakened points, the furious upheaval stopped and, the tractor beams shut off, the shattered, smoking, erupting ma.s.s of wreckage fell in clashing, grinding ruin upon the city.

The enormous duplex cone of the Vorkuls did not attempt to repeat the maneuver, but divided into two single cones, one of which darted toward each point of rupture. There, upon the broken and unprotected ends of the hexan cordon, their points of attack lay: theirs the task to eat along that annular fortress, no matter what the opposition might bring to bear--to channel in its place a furrow of devastation until the two cones, their work complete, should meet at the opposite edge of the city. Then what was left of the cones would separate into individual heptagons, which would so systematically blast every hexan thing into nothingness as to make certain that never again would they resume their insensate attacks upon the Vorkuls. Having counted the cost and being grimly ready to pay it, the implacable attackers hurled themselves upon their objectives.