Can the Daredevil of the Spaceways solve the secret of the invisible mastermind of crime?

The Interplanet Lines freighter Saturn Maid had just entered its parking orbit about Callisto, the jungle moon of Jupiter. Present on the bridge was Captain Nargo, a fat, dark-skinned, moon-faced Mercurian with the bright gold eyes of his race. He was there to make certain that his pilot entered orbit properly. Satisfied, he turned to his communications officer and was about to tell him to signal up the fleet of tugs which would unload the Saturn Maid of her valuable cargo, when he suddenly froze.

Someone was pressing the business end of a proton needle in the small of his back�

"This is The Blur speaking," a soft voice whispered in his ear. "Kindly instruct your officers to disarm themselves, and I assure you that no one will be harmed."

"Devils of the Darkside�!" the plump Mercurian choked furiously. Then he fell silent. Whoever the mystery mastermind known only as "The Blur" might be, he was the most cunning and successful corsair of the spaceways since the legendary days of Star Pirate himself. Although, unlike Star Pirate, The Blur did not hesitate to stain his hands with the blood of those foolish enough to get in his way.

"Mr. Urgon," the Captain said in strangled tones to the pilot, a red-faced Jovian giant, "you will remove your sidearm and lay it on the control console. You other gentlemen will do the same."

The burly Jovian stared in surprise. "But, Captain�!"

"Do as�I say, Mr. Urgon," growled the Mercurian officer in tones that would accept of no demur. Baffled, his officers disarmed themselves. The pressure of the proton needle left the small of Nargo's back. With furious eyes he watched as The Blur crossed the bridge to scoop up the weapons. As expected, he saw nothing but the slightest mist or haze where the figure of a man should have been fully visible�The Blur was aptly named, he thought bitterly to himself.

"Captain, we are being approached by an unmarked cruiser!" yelped a young ensign. The Captain turned to stare at the forward televisor screen and saw a lean, rakish craft.�It was painted dead black, and something about its slim, wolfish lines sent a cold shudder up the Mercurian's spine.

"That is my ship," The Blur whispered in his ear. "Instruct your men that the forward airlock doors be opened."

"Open the forward airlock doors," Nargo growled, fat cheeks quivering with frustrate fury.

The young ensign gave him a startled glance. "But, Captain�?"

"Do as you're told, boy!" snapped the Captain. "It may have escaped your notice, lad, but we are being pirated, curse the luck! There's a gun at my back even as I speak. Open those airlock doors, and be quick about it!" And with bitterness in his golden eyes, the Mercurian watched as a dozen unknown men with opaqued space helmets began transferring crate after heavy and ponderous crate to the nameless corsair craft. Those crates, he knew, held costly ingots of pure iridium, vanadium, chromium and ylemium from the metal refineries on Titan. The refined ore, almost one hundred percent pure, was worth an immense fortune.

"You have been very cooperative, Captain," hissed that hated voice in his ear. "Therefore, neither you nor any of your officers or crew have suffered injury. Be cooperative a brief while longer, and we will no longer interfere with your voyage ..."

"Go to the Devil, sir!" growled the Mercurian.

A soft chuckle was his only answer.

Moments later, the black cruiser drifted away from its linkage with the Saturn Maid, and vanished�becoming as invisible to the human eye as had been its mysterious master.

Within the hour, System-wide news services alerted a startled citizenry that The Blur had struck again!

The chairman of Interplanet Lines was a large, red-faced man named Pendleton whose hair was growing thin on top and whose temper was usually belligerent. As at the moment, for instance.

He glared accusingly across the gleaming expanse of his huge desk, carved from a heavy slab of costly Venusian goldenwood, at the Space Patrol officer who had just entered the executive suite. This was a granite-jawed veteran with thin lips and eyes like twin gimlets. His name was Brannigan. At the moment he was perspiring freely and striving to hold on to his own temper.

"�I assure you, Mr. Pendleton, that the Patrol is doing everything in its power to catch this crook who calls himself The Blur and to bring him to justice! That's why we have called upon persons such as yourself to cooperate with us�"

"Cooperate!" said Pendleton, with a rude snort. "Brannigan, everybody at Interplanet has cooperated fully with requests from the Patrol since first this madman ran amok and began raiding our freighters! You requested that we keep our ore shipments secret, and we kept them secret. You requested that we permit no passengers aboard our freighters, and passengers were forbidden, save for our own employees. You requested that all officers go armed in space, and we armed them all. And none of these measures did any good! Do you know how many credits that shipment of rare metals The Blur pirated from the Saturn Maid was worth, man? More credits than you'll earn in your entire career! And this is the sixth of these outrages this maniac has perpetrated against Interplanet!"

"I know, sir, but�!"

"But nothing!" growled Pendleton. "I've had enough of you and your cautious half-measures. The time has come to bring into play extraordinary resources�the extraordinary abilities and skills of a truly extraordinary man.�I refer to none other than�Star Pirate!"

Brannigan flushed and bit his lip. That mischievous, devil-may-care rogue of the spaceways had long been a thorn in the Patrol officer's side. In the days when he had been an outlaw, a thief and a living legend, he had outsmarted, outwitted and outflown Brannigan with merciless ease; then, when he grew bored with such easy victories and was offered an official pardon from the System Council, following his heroic endeavors in the affair of the Solar Queen, and turned his brilliant intelligence, his matchless skills as a space pilot and his intrepid bravery to the service of justice, he proved better at crime-fighting than Brannigan, and had solved more than one mystery crime that had left the Patrol officer helplessly baffled.

"You mustn't do that, sir!" Brannigan protested. "Whatever people think, the boy's nothing less than a cunning criminal�pardon or no pardon! Oh, he's got everybody fooled by pretending to work on the side of the law�but�I know better! And someday that clever young devil will trip himself up, and I'll have him at last! You know the old saying, sir�a leopard cannot change his spots. Once a crook, always a crook!"

The executive looked unconvinced. "And I'll remind you of another old saying," he said tartly. "Set a thief to catch a thief."

"But he's a common criminal�!"

"Rather an uncommon one, I'd say," snapped Pendleton sharply. "For seven years he ran you and the Patrol ragged. Ship after ship fell to him; he always showed you his heels and got away with the loot, and never once did he so much as spill a drop of blood in accomplishing this thievery. True?"

Brannigan dug out his handkerchief and swabbed his streaming brow. "True enough, sir, but�"

"The entire resources of the Patrol were hurled against him, and you couldn't even locate his secret base ... what does he call it, 'Haven'? As a matter of fact, even now that he works on the side of the law, it's my understanding that you of the Patrol still don't know where Haven is!"

"That's true enough, sir, but you don't�"

"Enough of this talk!" Pendleton said harshly. "You're a good man, no doubt, Brannigan, in your way. But you go by the rules . . . and what we need right now is someone who's not afraid to throw away the book and maybe even bend a law or two, just a little, in order to get the job done."

"But, sir, I�"

"I've met your chief, Carew, a time or two. An excellent officer, a shrewd judge of men, I'd say. I understand he trusts this Star Pirate implicitly. He's nobody's fool, Carew; fine old family. And if he trusts Star Pirate, then I trust Star Pirate!"

He turned to thumb his desktop televisor to life. The sweet, heartshaped face of a lovely girl with honey-blond curls and eyes as blue as April skies melted into view.

"Yes, Mr. Pendleton?"

"Get me Commander Carew at the Patrol base on Pallas, please, Robin.

Person-to-person; I'll deal with underlings no longer ..."

Between the orbits of Mars and Jupiter stretches that bewildering zone of shattered moonlets and whirling rocks known as the Asteroid Belt. In their unnumbered hundreds of thousands, the fragments of "Aster"�that lost world of space�circle in orbits and counterorbits of such complexity that even computers are often helpless to deduce their periodicity.

Some of the larger asteroids�Pallas, for example, where the Patrol maintains its regional headquarters, and Ceres, where the crops of corn and wheat and barley are grown that feed the Belt and its peoples, and a few others�are large enough to have sufficient gravitational pull to hold breathable atmospheres. The rest are airless rocks, sterile, architectural wizardry of time-lost Aster, it may be. Little is known for certain, although much is conjectured, about the Lost Planet which was (it is theorized) torn asunder in the grip of intolerable gravity tides in a relentless tug of war which took place many millions of years ago between the giant planets, Jupiter and Saturn and Uranus on the one hand, and the inner worlds and the mighty Sun itself. In that contest. Aster was destroyed ... but still Its weird, enigmatic ruins thrust their mystery against the cold mockery of the uncaring stars, on lost, unknown, unvisited moonlets that whirl giddily forever through the endless and cold night of space.

Haven is one of these, save that, unlike most of the asteroids, this miniature worldlet is warm and fertile, with a breathable atmosphere and near-Earth gravity. This was the result of the fact that, even though little more than a mile in width, the core of Haven is composed entirely of the very heaviest of metals. This lends Haven mass, and mass means gravity, and gravity means the ability for a body in space to hold air and moisture, which would otherwise be uselessly dissipated into the vacuum.

Star Pirate had discovered Haven and its strange ruins years before. Had not the twists and turns of fortune made of him, for a time�but only for a time�an outlaw and a buccaneer of the spaceways, his keen, searching intelligence and scholarly gifts might have made of him a space archaeologist. For his true interests lay with the immeasurable reaches of antiquity, the ancient past, of Earth and every other world.

Thus, as a youth, he had found Haven. Fascinated by its ruins and their indecipherable inscriptions, he had made his first base on the tiny moonlet. Years later, when he was being hounded from world to world by the Patrol, he remembered the tiny, uncharted fragment of immemorial Aster, and made of it his secret base. For Haven had this additional factor, beyond its warmth and atmosphere�it lay at the heart of a deadly whirling vortex of meteor swarms which were sudden death to any ship that did not know the tricks of safe passage through the vortex�which he had learned with infinite labor, and at the expensive loss of many radio-directed drone vessels.

Now it was home to him, who had no other home.

When Star Pirate concluded his conversation and Commander Carew's image had faded from the groundglass viewscreen, the lithe redhead turned to order Phath to get the Jolly Roger ready for space, but the white-skinned Venusian (who had shamelessly eavesdropped on their talk) was already lugging provisions into the cargo hold of the trim little speedster, and grinning at the prospect of some action for a change. Star had his weird ancient stone hieroglyphics to keep him busy between adventures, but Phath had nothing else but cooking their meals to occupy himself with, and he sometimes missed the good old days when the two of them had lived a wild career of outlawry and space piracy.

Once aboard and vacuum-sealed, Phath took the controls.

"Where to, Chief? Callisto?" Star shook his head slowly.

"We'll go there later; right now, head for Mars," he said.

"Mars?"

"Mars."

The Venusian shrugged. "Okay, Mars it is." Power surged from the rocket engines and the trim little speedster, the Jolly Roger, lifted on a plume of flame from the twilit, jungle-clad surface of the tiny moonlet. Phath switched on the computer pilot, which alone had reflexes swift enough to read the radio signals flashed from secret beacons on the whirling meteors, and which alone could safely pilot their craft through the deathly storm of churning fragments of stone and metal.

Phath joined Star Pirate in the cozy little lounge and handed him a steaming mug of good Venusian coffee. "This guy. The Blur, has a ship that just plain disappears, right, chief?" he inquired.

"That seems to be the case," admitted the redhead. "But how�and why�nobody knows."

The Venusian shrugged. "Same way The Blur goes invisible, don't you think, Star?"

"It's not just a matter of becoming invisible, Phath," said the other, sipping the delicious hot brew. "Visible or un, nobody searches for a moving spaceship with eyes alone� they move too fast. But they can't elude magno-detectors. Spaceships have hulls, and hulls are made of steel�"

"Which show up on magno-detectors," grinned Phath. "Yon're right, chief: spaceships are made of steel ... excepting when they aren't.�

Star Pirate made a noncommittal sound. Both he and Phath knew that the Jolly Roger did not contain an atom of ferrous metal, but was constructed from an alloy of noble metals so as to be completely undetectable in space. It was one of the many secrets of Star Pirate, and one which had, back in the old wild, lawless days, enabled him to come and go as he pleased, thumbing his nose at the Patrol.

But there were limits, even to such a trick. The Jolly Roger was a tiny two-man scout, while the lean, black, wolfish cruiser of The Blur was capacious enough to house a crew of at least twelve, as counted by eyewitnesses aboard the Saturn Maid, and to carry half a billion credits worth of ingots of iridium, chromium and vanadium�

He paused, struck by a sudden thought. It was as if the first ray of light had just penetrated the darkness which had up till now clung about this mystery. And Star grinned, that impish, reckless grin of his that Phath knew so well.

"By Yakdar's brazen backside, you're on to something already, aren't you, chief!" yelped the Venusian admiringly.

"None of your heathen Swamp Country curses aboard my ship," said Star Pirate with a pretense of sternness. "I'm taking a nap in my cabin; let me know when we get to Mount Mern."

Within the fifteen-foot-thick stone walls of the ancient Martian monastery, the air was purified, thickened, enriched with oxygen, and humidified. A fire roared on�the grate of the vast hearth, and warmed the empty room. The greenskinned savant served them fine old wine, curious Drylands fruits, native cheese, and succulent sausage meat.

"You will have a problem, lad, else you would not bother to intrude upon my studies," said Dr. Zoar. Star grinned sheepishly and admitted that this was so. The scientific part of his schooling had been left to the hands of the green dwarf, who possessed an intellect that was among the very finest in the system, and he had a healthy respect for Zoar's mind. He discussed The Blur with the diminutive Martian sage, and the problem of invisibility.

Zoar scowled over the problem, munching his portion of cheese and fruit and meat. Finally, the little Martian shrugged.

"So science has never conquered the problem!" he rasped. "Who cares? Of what possible utility would such a solution be? That is to say, how would the power to become invisible be of any use to men?"

"I don't know," admitted Star with a grin, "but it sure helps The Blur!"

Phath uttered a bark of laughter, almost strangling on a mouthful of sausage. Even Zoar permitted himself a rare grin. Then Star explained.

"If we know how he did it, we'd be a bit closer�perhaps�to learning who he is," said the redhead. Zoar chewed some cheese, ruminating, unable to find a flaw in Star's argument .

"You know what angstroms are?" he demanded suddenly.

"The measure of electromagnetic energy," said the Earthling.

"You know the angstroms which measure the part of the electromagnetic spectrum devoted to visible light?�

"I do," said Star Pirate. Zoar nodded, satisfied, then poured them all another cup of black Martian wine.

"And does your knowledge of the history of recent centuries extend to the principles of radio-jamming? Of broadcasting on the same frequency in order to blanket, to negate, to wipe out, the original broadcast?" inquired the diminutive sage.

The light of cognition illuminated the space-tanned features of the young redhead in the gray zippersuit. He nodded dumbly.

"Excellent!" said Dr. Zoar, reaching for the cold stone bottle of wine. "Do have a drop or two more . . . I am delighted to learn that your, ah, association with our webfooted friend here has not, as I might very well have feared, dimmed your intelligence."

Phath glowered, scowled, but said nothing. For one thing, his mouth was full of sausage and cheese at the moment. For another, there was nothing much to be said. He and Zoar had never been able to agree on anything, except for their mutual devotion to the redheaded youth who was their leader.

"And is there another problem with which I may help, perchance, with my feeble wits?" purred Dr. Zoar. He was feeling fine, having already solved the mystery of The Blur's invisibility�at least to his own satisfaction.

Star Pirate cleared his throat, and mentioned the puzzle of the utter disappearance of the dead-black cruiser, once it was finished robbing a cargo ship off Callisto. According to the magno-detectors of the Callistan Port Authority, the pirate craft had neither landed in the fungus-forests of that jungle moon, nor had it journeyed into deep space. It had simply vanished from human knowledge.

"Nonsense," snapped Zoar, helping himself to another noggin of the excellent wine. "There is an answer to every question, elsewise that question could not be asked. All that is required is the application of human intelligence ... of knowledge . . .ah! Yes; of course; or, at least, perhaps. For I cannot be certain, without investigation. Tell me, boy�what is unique about Callisto, moon of Jupiter?"

Star Pirate wrinkled his brow, frowning in thought.

"Well," he said at length, "for one thing, it's the largest known moon in the System, large enough to be counted as a planet, like Mercury, if it was in free orbit around the Sun and not in a captive orbit about Jupiter."

"True enough," grunted Dr. Zoar. "But what else?"

Star scowled, rubbing his brow. "Well, it has an atmosphere, but, then, so have lo and Ganymede, and�

"No, not that. Think, boy! Think!" rapsed the old Martian savant.

Star racked his brain, somewhat befuddled by the old strong Martian wine, but not to any great degree. Suddenly his brow cleared and he grinned his famous grin, and uttered a brief sentence of seven words, which made Phath blink incredulously, but Zoar grin with delight.

"Ah! Splendid!" crowed the old savant. "It heartens me that your deplorable relationship with this web-footed swamp-lizard has not�as I feared it might do, by now�sapped your Intellectual vigor! Well, my boy, I believe that you are now in possession of all the data you require in order to bring the depredations of this bandit of the spaceways to an end, so�I will bid you and your, um, confederate, farewell, and return to my studies ..."

They waded back across the stony plateau, leaning against the bitter wind, masked against the dry air, all the way to where the Jolly Roger awaited their coming. Star Pirate had a pretty fair notion that he now held the keys to this mystery in his hands, but, as for Patth,�the milk-pale Venusian was completely in the dark.

The Interplanet Lines freighter Uranus Gal paused briefly at Titan to take aboard a large shipment of semi-precious metal ore in purified ingot form, before breaking orbit and directing its flight to Callisto.

The only persons aboard who were not either officers or crewmen were two company officials, a secretary in the employment of Interplanet and one of the Interplanet scientists, who had been studying radionic energy waves in the gulfs beyond Saturn.

The purser, however, was a new man, unknown to the crew. He had curly red hair, mischievous green eyes, an impish grin, and had found it remarkably easy to make friends aboard ship.

In the course of time, the Uranus Gal arrived in parking orbit around Callisto, and the Captain, a yellowskinned Uranian called Quolk, prepared to instruct his communications officer to call up the tugs which would carry down to the surface of the jungle moon his cargo of semiprecious metals.

There occurred, however, an interruption in these plans. In the form of the muzzle of a proton needle, thrust against the spine of Captain Quolk by a hand unseen.

A cold voice whispered in his ear: "This is The Blur speaking. Place your weapon on the console and instruct your officers to similarly disarm themselves, and�I will guarantee to you that none of your people will be hurt. Disobey, and�I refuse to become responsible for the consequences."

Quolk stiffened, glared, then subsided, grumbling. He plucked his proton needle from its holster and placed it atop the control console. Then, just as he was about to raise his voice and instruct the others on the bridge to do the same, an unexpected voice spoke from the rear.

"This, friend Blur, is the pressure of a proton needle planted in your own back," the voice said pleasantly. "Now, unless you would enjoy having a sizeable portion of your backbone reduced to drifting atoms�which I really do not think you would enjoy at all�I suggest that you drop your needier on the floor. And if you happen to bear any other weapon, drop that one, too. Because, in the ancient turn of phrase, Blur, the jig is up."

There ensued a few moments of utter silence. Then there came to the ears of all in the vicinity the thud of a handgun dropped to the flooring. Moments later, the weapon melted into visibility.

With one foot. Star Pirate kicked it well away from where he stood behind The Blur.

He twisted the vernier on the power unit he wore, this way and that, until suddenly sparks sizzled and a shadowy figure came slowly into view, standing between him and the Uranian, Captain Quolk. It was slight, bent, and draped in a veil of dark cloth.

"Star Pirate,�I believe," whispered the veiled figure, with a slight bow of the head.

Star nodded slightly�not for one moment relaxing the pressure of the proton needle he held firmly against the spine of The Blur.

"Professor Jonas Pertinax,�I believe," he said, and it was observed by Captain Quolk and one or another of the officers on the bridge that the dark-veiled figure, now fully visible, flinched violently.

"How did you ... know my name?" hissed the veiled one. Star Pirate laughed, and reached out and twitched away the veil, revealing a balding, elderly Earthling with rheumy blue eyes, a large nose, and not much chin.

"You were listed as present on several of the trips made by Interplanet freighters when they were raided by The Blur," he said. "And your speciality is in the field of electromagnetic radiation. It did not take very much detective work to discover that on three different occasions you contested in court Interplanet's claim to certain patents resulting from your work�"

"For which�I was inadequately paid," hissed the balding scientist in venomous tones. "I decided to use my genius�which they valued so little!�to reduce Interplanet to beggary. The which�I would have done, had not you come meddling into affairs which have naught to do with you�"

"Captain Quolk, an unmarked cruiser is suddenly in the vicinity, and is closing upon us with magnetic grappling beams," cried an ensign.

"Quite all right," declared the yellow-skinned Uranian. "Bosun, conduct Professor Pertinax to the brig, and lock him up. But first�I want the prisoner subjected to a strip-search, in case he has any of his nasty little gadgets on him!"

Star laughed and slapped Pertinax between the shoulders, where he appeared to have a natural hump. "Oh,�I doubt if you'll find anything other than this�it's the instrument which made him seem invisible to us."

"Is it really?" asked the Uranian, curiously. "How does the thing work?"

"Quite simply, really," said the Pirate. "it broadcasts a jamming frequency in the same wavelengths as visible light, but in a globular and heterodyning field, which in effect bends light around the figure wearing it, so that it vanishes to our sight. Clever, but not all that mysterious."

Stripped of his invisibility projector, The Blur was led off between burly men-at-arms. Quolk turned to his "purser" with rare good humor in his beaming smile.

"And what will we do about yonder black wolf?" he boomed, gesturing at the corsair ship.

"Nothing. When the airlocks do not open, The Blur's men will guess something has gone wrong, and will flee to their base," said Star. "What they will not guess, is that my own ship is waiting�and that�I already know where they are going!"

The Uranian bent upon the redhaired youth a stern but admiring gaze. "You are quite a remarkable young man," he said softly.

"Not at all, actually," grinned Star. "Callisto is famous and unique for more than one reason. One of these is that it is the only moon in the System�actually, it's big enough to be considered a planet, and would be, if, like Mercury, it circled the Sun and not another planet�the only moon in the System,�I say, that has a moon of its own. This miniature moonlet is known as Callisto-Alpha. It's less than half a mile wide, and nobody ever remembers it's there ... except for a certain old Martian scientist�I happen to know. Well, that's the site of the secret base of The Blur's raiders. It has to be: there's nowhere else to go; if you don't land on Callisto, or go off into deep space, you have to land on Callisto-Alpha, to unload your ingots of rhodium and vanadium and�"

"Why did The Blur concentrate on metals like that, anyway, I wonder?" muttered Captain Quolk. Star Pirate grinned again.

"I can even answer that one, too, I think! He wanted to get a sufficiency of non-ferrous metals to build an indetectable space-cruiser that wouldn't show up on a magno-detector! This would give The Blur and his gang of outlaws the freedom to roam the spaceways at will, leaving the Space Patrol helpless to pursue them. They could have preyed upon the shipping of world after world, bringing Interplanet Lines to its knees. And when we investigate The Blur's base on Callisto-Alpha, I'll bet you fifty credits we find a space-cruiser made of noble metals, and about half-built!"

Captain Quolk heaved a hearty sigh of relief.

"Young fellow, you are a remarkable person. And if you don't mind accompanying me to my quarters, I have been hoarding a cask of century-old Martian fire-brandy for just such an occasion as this one has proved to be ..."

"Lead the way, sir," said Star Pirate, with a smile.