by Unknown
Had the murdered man really bumped into an invisible airship, or hadhe only thought he had? Had those devils learned to apply the gas tothe surfaces of airplanes? There was no reason why they should nothave done so.
But surely the utmost ingenuity of man had not contrived to render amodern plane, with its metalwork and machinery, absolutelytransparent?
* * * * *
And, again, how was it possible to have silenced the sound of engines,the whir of a propeller, so that there should be no auditoryindication whatever of a plane's presence?
Dick looked all about him. Nothing was in the air--he could have swornit. He replaced the soaring lever and banked in a close circle, hisglance piercing the night. No, there was nothing.
Crash! Boom! The plane rocked violently, tossing upon gusts of air. Ahuge, gaping hole of blackness had suddenly appeared in the middle ofthe White House lawn. The tents were flat upon the ground. Through therising smoke clouds Dick saw tongues of flame.
No shell that, but a bomb, and dropped from the skies less than fivehundred feet from where Dick hovered. Yet there was nothing visible inthe skies save the round orb of the moon.
A rush of wind past Dick's face! One of the vanes of the helicoptercrumpled and fluttered away into the night. Dick needed no furtherpersuasion. The dead soldier had not lied.
Von Kettler had begun the fulfillment of his threat!
CHAPTER V - The Enemy Strikes
As Dick's airship veered and side-slipped, he kicked hard on the leftrudder and brought the nose around. Furiously he sprayed the air witha leaden hail from his quick-firer. He heard a rush of wind go pasthim, and realized that his unseen antagonist had all but rammed him.
Yet nothing was visible at all, save the moon and the empty sky. Hehad heard the rush of the prop-wash, but he had seen nothing, heardnothing else. Incredible as it seemed, the pilot was flying a planethat had attained not merely invisibility but complete absence of allsound.
Dick side-slipped down, pancaked, and crashed. He emerged from a planewrecked beyond hope of early repair, yet luckily with no injury beyonda few minor bruises. He rushed toward the hangar, to encounter a bevyof scared mechanics.
"Another plane! Rev one up quick!" he shouted.
Planes were already being wheeled out, pilots in flying suits andgoggles were striding beside them. Dick ordered one of them away,stepped into his plane, and in a moment was in the air again.
In the minute or two that had elapsed since the encounter, the enemyhad been active. Crash after crash was resounding from various partsof Washington. Buildings were rocking and toppling, débris strewed thestreets, fires were springing up everywhere. A thousand feet aloft,Dick could see the holocaust of destruction that was being wrought bythe infernal missiles.
Bombs of such power had been the unattained ambition of everygovernment of the world--and it had been left to the men of theInvisible Emperor to attain to them. Whole streets went into ruin ateach discharge and from everywhere within the city the wailing cry ofthe injured went up, in a resonant moan of pain.
In the central part of the city, the district about F Street and thegovernment buildings, nothing was standing, except those buildingsfashioned of structural steel, and these showed twisted girders likethe skeletons of primeval monsters, supporting sections of saggingfloors. Houses, hotels had melted into shapeless heaps of rubble,which filled the streets to a depth of a dozen yards, buryingeverything beneath them. Yet here and there could be seen the forms ofdead pedestrians, motor-cars emerging out of the débris, lying inevery conceivable position; horses, horribly mangled, were shriekingas they tried to free themselves. And yet, despite this ruin, thegeneral impression upon Dick's mind, as he beat to and fro, signalingto his flight to spread, was that of a vast, empty desolation.
* * * * *
Further away: where the ruin had not yet fallen, thousands of humanbeings were milling in a mass, those upon the fringes of the crowdperpetually breaking away, other swarms approaching them, so that theentire agglomeration resembled a seething whirlpool turning slowlyupon itself.
Then of a sudden the strains of the national anthem floated up toDick's ears. A band was playing in the White House grounds. The tunewas ragged, and the drum came in a fraction of a second late, but animmense pride and elation filled Dick's soul.
"They'll never beat us!" he thought, intensely, "with such a spiritas that!"
He had signaled his flight to spread, and search the air. He could seethe individual ships darting here and there over the immensity of thecity, but none knew better than he how fruitless their effort was. Andthe marauders had not ceased their deadly work.
A bomb dropped near the Washington Monument, sending up a huge spoutof dust that veiled it from his eyes. Instinctively Dick shot towardthe scene. Slowly the dust subsided, and then a yell of exultationbroke from Dick's lips. The noble shaft still stood, a slim taperpointing to the skies.
It was an omen of ultimate success, and Dick took heart. No, they'dnever beat the grim, unconquerable tenacity of the American people.
Yet the damage was proceeding at a frightful rate. A bomb droppedsquarely on the Corcoran Gallery and resolved it into a heap of sillystones. A bomb fell in the middle of Pennsylvania Avenue, and thehouses on either side collapsed like houses of cards, falling into asulphurous, fiery pit. And still there was nothing visible but the skyand the moon.
* * * * *
Dick gritted his teeth and swore as he circled over the site ofdestruction, out of which tiny figures were struggling. He heard theclang of the fire bells as the motor trucks came roaring toward thescene. Then crash! again. Five blocks northward another dense cloud ofdust arose, and the new area of destruction, spreading as swiftly asripples over a pond, joined the former one, leaving a huge, irregularopen space, piled up with masonry and brick in a number of flat-toppedpyramids.
Into this, houses went crashing every moment, with a sound like theclatter of falling crockery, but infinitely magnified.
"The devils! The swine!" shouted Dick. "And we gave Von Kettler theprivileges of an ambassador!"
And Fredegonde was the sister of this devil! The remembrance of thatstruck a cold chill to Dick's heart again. He tried to blot out herpicture from his mind, but he still saw her as she had appeared thatday after the air ride, flushed, smiling, radiant in her dark beauty.
A murderess and a spy! He cursed her as he banked and circled back. Hewas helpless. He could do nothing. And all Washington would bedestroyed by morning, if the supply of bombs kept up. But there wasmore to come. Suddenly Dick became aware that two of his flight, atwidely separated distances, were going down in flames. Flaming comets,they dropped plump into the destruction below. Another caught fire andwas going down. No need to question what was happening.
The invisible enemy was attacking his flight and picking off his menone by one!
He drove furiously toward two of his planes whose erratic movementsshowed that they were being attacked. As he neared them he saw onecatch fire and begin its earthward swoop. Then the fuselage crackledbeside him, and his instrument board dissolved into ruin.Instinctively he went round in a tight bank and loosed hismachine-gun. Nothing there! Nothing at all! Yet his right wing wentragged, and his own furious blasts into the sky, their echoes drownedby the roar of his propeller, were productive of nothing.
* * * * *
He shot past the uninjured plane, signalling it to descend. He wasn'tgoing to let his men ride aloft to helpless butchery. Nothing could bedone until some means was discovered of counteracting the enemy'sterrific advantage.
He darted across the heart of the city to where another of the flightwas circling, waggling his wings to indicate to it to descend. Then onto the next plane and the next, shepherding them. Thank God theyunderstood! They were bunching toward the hangar. Yet another tookfire and dropped, a burning wreck. Half his flight out of commission,and not an enemy visible!
He was aloft alone now, courting death--instant, invisible death. Hewouldn't desce
nd until that carnival of murder was at an end. But itwas not at an end. Another crash, far up Pennsylvania Avenue, showedan attempt upon the Capitol. Again--again, and a smoking hell wreathedthe noble buildings so that it was no longer possible to see them. Alull, and then a crash nearer the city's heart. Crash! Crash!
Invisible though the enemy was, it was easy to trace the movements ofthis particular plane by the successive areas of destruction that itleft behind it. It was coming back over Pennsylvania Avenue, droppingits bombs at intervals. It was methodically wiping out an entiresection of Washington.
Dick drove his plane toward it. There was one chance in a thousandthat, if he could accurately gauge the progress of his invisibleantagonist, he could crash him and go down with him to death. If hecould get close enough to feel his prop-wash! A wild chance, butDick's mind was keyed up to desperation. He shot like an arrow towardthe scene, with a view to intercepting the murderer.
Then of a sudden he became aware of a curious phenomenon. A black beamwas shooting across the sky. A black searchlight! It came from theflat top of a large hotel that had somehow escaped the universaldestruction, and, with its gaunt skeleton of structural steel showingin squares, towered out of the ruin all about it like an island.
* * * * *
It was from here that the black beam started. It spread fanwise acrossthe sky. But it was not merely blackness. It was utter andimpenetrable darkness, cleaving the sky like a knife. Where itpassed, the rays of the moon were extinguished as fire is extinguishedby water.
A beam of absolute blackness, that pierced the air like a wideningcone, and made the night seem, by contrast, of dazzling brightnessalong either dark border.
High into the air that dark beam shot, moving to and fro in the sky.Dick, darting toward the spot where he hoped to find his invisibleenemy, found himself caught in it.
In utter, inextinguishable darkness! Like a trapped bird he fluttered,hurling himself this way and that till suddenly he found himselfblinking in the dazzling light of the moon again, and the black beamwas overhead.
Crash! Another widening sphere of ruin as the invisible marauderdropped a bomb. Dick cursed bitterly. Trapped in that black beam, hehad lost his direction. The invisible plane had shot past the pointwhere he had hoped to intercept it.
He flung his soaring lever, and hung suspended in the air. An easymark for the enemy, if he chose to take the opportunity. No matter.Death was all that Dick craved. He had seen half his flight wiped out,and a hundred thousand human beings hurled to destruction. He wantedto die.
Then suddenly a wild shout came to his ears, as if all Washington hadgone mad with triumph. And Dick heard himself shouting too, before heknew it, almost before he knew why.
* * * * *
For overhead, where the inky finger searched the sky, a luminous shapeappeared, a silvery cigar, riding in the void. The finger missed it,and again there was only the moonlight. It caught it again--and againthe whole devastated city rang with yells of derision, hate, and angeras the black beam held it.
It held it! To and fro that silvery cigar scurried in a franticattempt to avoid detection, and remorselessly the black beam held itdown.
It held it down, and it outlined it as clearly as a figure on themoving picture screen. Then suddenly there came a flash, followed by adull detonation, and a black cloud appeared, spreading into a flowerof death near the cigar, and at the edge of the black beam. The cheersgrew frantic. The anti-aircraft battery in the White House grounds hadgrasped the situation, and was opening fire.
To and fro, like a trapped beast, the cigar-shaped airplane fled. Onceit seemed to escape. It faded from the edge of the black finger--fadedinto nothingness amid a roar of execretion. Then it was caught andheld.
Truncated, bounded by an arc of sky, the black finger followed themurderer in his flight remorselessly. And all around him theanti-aircraft guns were placing a barrage of death.
He was trapped. No need for Dick to rush in to battle. To do so mightcall off that deadly barrage that held the murderer in a ring ofdeath. Hovering, Dick watched. And then, perhaps panic-stricken,perhaps rendered desperate, perhaps through sheer, wanton courage thatmight have commanded admiration under nobler circumstances, theairship turned and drove straight in the direction of the battery,dropping another bomb as she did so.
* * * * *
It fell in a crowded street, swarming with spectators who hadclambered upon the fallen débris, and it wrought hideous destruction.But this time there was hardly a cry--no unison of despair such as hadcome to Dick's ears before. The suspense was too tense. All eyeswatched the airship as, seeming to bear a charmed life, she drove forthe White House itself, through a ring of shells that widened andcontracted alternately, with the object of placing a last bombsquarely upon the building before going down in death. And all thewhile the black searchlight held it.
Dick Rennell was to experience many thrilling moments afterward, butthere was never a period, measurable by seconds, yet seeming to extendthrough all eternity--never a period quite so fraught with suspenseas, hovering there, he watched the flight of that silvery planespeeding straight toward the executive mansion while all around it theshells bloomed and spread. It was over the White House grounds. Thearchies had failed; they were being outmaneuvered, they could not beswung in time to follow the trajectory of the plane. Dick held hisbreath.
Then suddenly the silvery ship dissolved in a blaze of fire, a showerof golden sparks such as fly from a rocket, and simultaneously thelast bomb that she was to drop broke upon the ground below.
Down she plunged, instantly invisible as she escaped the finger of theblack beam; but she dropped into the vortex of ruin that she herselfhad created. Into a pit of blazing fire, criss-crossed by fallingtrees, that had engulfed the battery and a score of men.
Then suddenly Dick understood. He flung home the soaring lever,banked, and headed, not for the White House, but for the flat roof ofthe hotel from which the black searchlight was still projecting itselfthrough the skies. He hovered above, and dropped, light as a feather,upon the rooftop.
* * * * *
There was only one person there--an old man dressed in a shabby suit,kneeling before a great block of stone that had been dislodged upwardfrom the parapet and formed a sort of table. Upon this table the oldman had placed a large, square box, resembling an exaggerated kodak,and it was from the lens of this box that the black beam wasprojecting.
Dick sprang from his cockpit as the old man rose in alarm. He ran tohim and caught him by the arm.
"Luke Evans!" he cried. "Thank God you've come back in time to saveAmerica!"
CHAPTER VI - The Gas
In the Blue Room of the White House the Council listened to old LukeEvans's exposition of his invention with feelings ranging fromincredulity to hope.
"I've been at work all the time," said the old man, "not far fromhere. I knew the day would come when you'd need me. I put my prideaside for the sake of my country."
"Tell us in a few words about this discovery of yours, Mr. Evans,"said Colonel Stopford.
Luke Evans placed the square black case upon the table. "It's simple,like all big things, sir," he answered. "The original shadow-breakingdevice that I invented was a heavy, inert gas, invisible, but almostas viscous as paint. Applied to textiles, to inorganic matter, toanimal bodies, it adheres for hours. Its property is to render suchsubstances invisible by absorbing all the visible light rays that fallupon it, from red to violet. Light passes through all substances thatare coated with this paint as if they did not exist."
"And this antidote of yours?" asked Colonel Stopford.
"Darkness," replied Luke Evans. "A beam of darkness that meansabsolute invisibility. It can be shot from this apparatus"--heindicated the box upon the table. "This box contains a minute portionof a gas which exists in nature in the form of a black, crystallinepowder. The peculiar property of this powder is that it is thesolidified form of a gas more volatile than any that is known. Sovolatile is it that, when the ordi
nary atmospheric pressure of fifteenpounds to the square inch is removed, the powder instantly changes tothe gaseous condition."
"By pressing this lever"--Evans pointed at the box--"a vacuum iscreated. Instantly the powder becomes a gas, which shoots forththrough this aperture with the speed of a projectile, taking the formof a beam of absolute blackness. Or it can be discharged fromcylinders in such a way as to extend over a large area within a fewminutes."
"But how does this darkness make the invisible airships luminous?"asked Stopford. "Why does not your darkness destroy all light?"
"In this way, sir," replied the old inventor. "The shadow-breaking gaswith which the airships are painted confers invisibility because itabsorbs sunlight. But it does not absorb the still more rapid waves,or oscillations which manifest themselves as radio-activity. On thecontrary, it gathers and reflects these.
"Now Roentgen, the discoverer of the X-ray, observed that if X-raysare allowed to enter the eye of an observer who is in completedarkness, the retina receives a stimulus, and light is perceived, dueto the fluorescent action of the X-rays upon the eyeball.
"Consequently, by creating a beam of complete darkness, I bring intoclear visibility the fluorescent gas that coats the airships; in otherwords, the airships become visible."
"If a light ray is nullified upon entering the field of darkness, willit emerge at the other edge as a perfect light ray again?" askedStopford.
"It will emerge unchanged, since the black beam destroys light byslightly slowing down the vibrations to a point where they are notperceived as light by the human eye. On emerging from the beam,however, these vibrations immediately resume their natural frequency.To give you a homely parallel, the telephone changes sound waves toelectric waves, and re-converts them into sound waves at the otherend, without any appreciable interruption."
"Then," said Stopford, "the logical application of your method is toplunge every city in the land into darkness by means of this gas?"