A
nd, again, how was it possible to have silenced the sound of engines, the whir of a propeller, so that there should be no auditory indication whatever of a plane's presence?
Dick looked all about him. Nothing was in the air—he could have sworn it. He replaced the soaring lever and banked in a close circle, his glance piercing the night. No, there was nothing.
Crash! Boom! The plane rocked violently, tossing upon gusts of air. A huge, gaping hole of blackness had suddenly appeared in the middle of the White House lawn. The tents were flat upon the ground. Through the rising 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 in the skies save the round orb of the moon.
A rush of wind past Dick's face! One of the vanes of the helicopter crumpled and fluttered away into the night. Dick needed no further persuasion. The dead soldier had not lied.
Von Kettler had begun the fulfillment of his threat!
A
s Dick's airship veered and side-slipped, he kicked hard on the left rudder and brought the nose around. Furiously he sprayed the air with a leaden hail from his quick-firer. He heard a rush of wind go past him, and realized that his unseen antagonist had all but rammed him.
Yet nothing was visible at all, save the moon and the empty sky. He had heard the rush of the prop-wash, but he had seen nothing, heard nothing else. Incredible as it seemed, the pilot was flying a plane that had attained not merely invisibility but complete absence of all sound.
Dick side-slipped down, pancaked, and crashed. He emerged from a plane wrecked beyond hope of early repair, yet luckily with no injury beyond a few minor bruises. He rushed toward the hangar, to encounter a bevy of scared mechanics.
"Another plane! Rev one up quick!" he shouted.
Planes were already being wheeled out, pilots in flying suits and goggles 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 enemy had been active. Crash after crash was resounding from various parts of Washington. Buildings were rocking and toppling, débris strewed the streets, fires were springing up everywhere. A thousand feet aloft, Dick could see the holocaust of destruction that was being wrought by the infernal missiles.
Bombs of such power had been the unattained ambition of every government of the world—and it had been left to the men of the Invisible Emperor to attain to them. Whole streets went into ruin at each discharge and from everywhere within the city the wailing cry of the injured went up, in a resonant moan of pain.
In the central part of the city, the district about F Street and the government buildings, nothing was standing, except those buildings fashioned of structural steel, and these showed twisted girders like the skeletons of primeval monsters, supporting sections of sagging floors. Houses, hotels had melted into shapeless heaps of rubble, which filled the streets to a depth of a dozen yards, burying everything beneath them. Yet here and there could be seen the forms of dead pedestrians, motor-cars emerging out of the débris, lying in every conceivable position; horses, horribly mangled, were shrieking as they tried to free themselves. And yet, despite this ruin, the general impression upon Dick's mind, as he beat to and fro, signaling to his flight to spread, was that of a vast, empty desolation.
F
urther away: where the ruin had not yet fallen, thousands of human beings were milling in a mass, those upon the fringes of the crowd perpetually breaking away, other swarms approaching them, so that the entire agglomeration resembled a seething whirlpool turning slowly upon itself.
Then of a sudden the strains of the national anthem floated up to Dick's ears. A band was playing in the White House grounds. The tune was ragged, and the drum came in a fraction of a second late, but an immense pride and elation filled Dick's soul.
"They'll never beat us!" he thought,intensely, "with such a spirit as that!"
He had signaled his flight to spread, and search the air. He could see the individual ships darting here and there over the immensity of the city, but none knew better than he how fruitless their effort was. And the marauders had not ceased their deadly work.
A bomb dropped near the Washington Monument, sending up a huge spout of dust that veiled it from his eyes. Instinctively Dick shot toward the scene. Slowly the dust subsided, and then a yell of exultation broke from Dick's lips. The noble shaft still stood, a slim taper pointing to the skies.
It was an omen of ultimate success, and Dick took heart. No, they'd never beat the grim, unconquerable tenacity of the American people.
Yet the damage was proceeding at a frightful rate. A bomb dropped squarely on the Corcoran Gallery and resolved it into a heap of silly stones. A bomb fell in the middle of Pennsylvania Avenue, and the houses on either side collapsed like houses of cards, falling into a sulphurous, fiery pit. And still there was nothing visible but the sky and the moon.
D
ick gritted his teeth and swore as he circled over the site of destruction, out of which tiny figures were struggling. He heard the clang of the fire bells as the motor trucks came roaring toward the scene. Then crash! again. Five blocks northward another dense cloud of dust arose, and the new area of destruction, spreading as swiftly as ripples over a pond, joined the former one, leaving a huge, irregular open space, piled up with masonry and brick in a number of flat-topped pyramids.
Into this, houses went crashing every moment, with a sound like the clatter of falling crockery, but infinitely magnified.
"The devils! The swine!" shouted Dick. "And we gave Von Kettler the privileges of an ambassador!"
And Fredegonde was the sister of this devil! The remembrance of that struck a cold chill to Dick's heart again. He tried to blot out her picture from his mind, but he still saw her as she had appeared that day 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. He was helpless. He could do nothing. And all Washington would be destroyed by morning, if the supply of bombs kept up. But there was more to come. Suddenly Dick became aware that two of his flight, at widely separated distances, were going down in flames. Flaming comets, they dropped plump into the destruction below. Another caught fire and was going down. No need to question what was happening.
The invisible enemy was attacking his flight and picking off his men one by one!
He drove furiously toward two of his planes whose erratic movements showed that they were being attacked. As he neared them he saw one catch fire and begin its earthward swoop. Then the fuselage crackled beside him, and his instrument board dissolved into ruin. Instinctively he went round in a tight bank and loosed his machine-gun. Nothing there! Nothing at all! Yet his right wing went ragged, and his own furious blasts into the sky, their echoes drowned by the roar of his propeller, were productive of nothing.
H
e shot past the uninjured plane, signalling it to descend. He wasn't going to let his men ride aloft to helpless butchery. Nothing could be done until some means was discovered of counteracting the enemy's terrific advantage.
He darted across the heart of the city to where another of the flight was circling, waggling his wings to indicate to it to descend. Then on to the next plane and the next, shepherdingthem. Thank God they understood! They were bunching toward the hangar. Yet another took fire 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. He wouldn't descend until that carnival of murder was at an end. But it was not at an end. Another crash, far up Pennsylvania Avenue, showed an attempt upon the Capitol. Again—again, and a smoking hell wreathed the noble buildings so that it was no longer possible to see them. A lull, and then a crash nearer the city's heart. Crash! Crash!
Invisible though the enemy was, it was easy to trace the movements of this particular plane by the successive areas of destruction that it left behind it. It was coming back over Pennsylvania Avenue, dropping its bombs at intervals. It was methodically wiping out an entire section of Washington.
Dick drove his plane toward it. There was one chance in a thousand that, if he could accurately gauge the progress of his invisible antagonist, he could crash him and go down with him to death. If he could get close enough to feel his prop-wash! A wild chance, but Dick's mind was keyed up to desperation. He shot like an arrow toward the scene, with a view to intercepting the murderer.
Then of a sudden he became aware of a curious phenomenon. A black beam was shooting across the sky. A black searchlight! It came from the flat top of a large hotel that had somehow escaped the universal destruction, and, with its gaunt skeleton of structural steel showing in squares, towered out of the ruin all about it like an island.
I
t was from here that the black beam started. It spread fanwise across the sky. But it was not merely blackness. It was utter and impenetrable darkness, cleaving the sky like a knife. Where it passed, the rays of the moon were extinguished as fire is extinguished by water.
A beam of absolute blackness, that pierced the air like a widening cone, and made the night seem, by contrast, of dazzling brightness along 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 invisible enemy, 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 himself blinking in the dazzling light of the moon again, and the black beam was overhead.
Crash! Another widening sphere of ruin as the invisible marauder dropped a bomb. Dick cursed bitterly. Trapped in that black beam, he had lost his direction. The invisible plane had shot past the point where he had hoped to intercept it.
He flung his soaring lever, and hung suspended in the air. An easy mark 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 wanted to die.
Then suddenly a wild shout came to his ears, as if all Washington had gone mad with triumph. And Dick heard himself shouting too, before he knew it, almost before he knew why.
F
or overhead, where the inky finger searched the sky, a luminous shape appeared, a silvery cigar, riding in the void. The finger missed it, and again there was only the moonlight. It caught it again—and again the whole devastated city rang with yells of derision, hate, and anger as the black beam held it.
It held it! To and fro that silvery cigar scurried in a frantic attempt to avoid detection, and remorselessly the black beam held it down.
It held it down, and it outlined it as clearly as a figure on the moving picture screen. Then suddenly there came a flash, followed by a dull detonation, and a black cloud appeared, spreading into a flower of death near the cigar, and at the edge of the black beam. The cheers grew frantic. The anti-aircraft battery in the White House grounds had grasped the situation, and was opening fire.
To and fro, like a trapped beast, the cigar-shaped airplane fled. Once it seemed to escape. It faded from the edge of the black finger—faded into nothingness amid a roar of execretion. Then it was caught and held.
Truncated, bounded by an arc of sky, the black finger followed the murderer in his flight remorselessly. And all around him the anti-aircraft guns were placing a barrage of death.
He was trapped. No need for Dick to rush in to battle. To do so might call off that deadly barrage that held the murderer in a ring of death. Hovering, Dick watched. And then, perhaps panic-stricken, perhaps rendered desperate, perhaps through sheer, wanton courage that might have commanded admiration under nobler circumstances, the airship turned and drove straight in the direction of the battery, dropping another bomb as she did so.
I
t fell in a crowded street, swarming with spectators who had clambered upon the fallen débris, and it wrought hideous destruction. But this time there was hardly a cry—no unison of despair such as had come to Dick's ears before. The suspense was too tense. All eyes watched the airship as, seeming to bear a charmed life, she drove for the White House itself, through a ring of shells that widened and contracted alternately, with the object of placing a last bomb squarely upon the building before going down in death. And all the while the black searchlight held it.
Dick Rennell was to experience many thrilling moments afterward, but there was never a period, measurable by seconds, yet seeming to extend through all eternity—never a period quite so fraught with suspense as, hovering there, he watched the flight of that silvery plane speeding straight toward the executive mansion while all around it the shells bloomed and spread. It was over the White House grounds. The archies had failed; they were being outmaneuvered, they could not be swung in time to follow the trajectory of the plane. Dick held his breath.
Then suddenly the silvery ship dissolved in a blaze of fire, a shower of golden sparks such as fly from a rocket, and simultaneously the last bomb that she was to drop broke upon the ground below.
Down she plunged, instantly invisible as she escaped the finger of the black beam; but she dropped into the vortex of ruin that she herself had created. Into a pit of blazing fire, criss-crossed by falling trees, 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 of the hotel from which the black searchlight was still projecting itself through the skies. He hovered above, and dropped, light as a feather, upon the rooftop.
T
here was only one person there—an old man dressed in a shabby suit, kneeling before a great block of stone that had been dislodged upward from the parapet and formed a sort of table. Upon this table the old man had placed a large, square box, resembling an exaggerated kodak, and it was from the lens of this box that the black beam was projecting.
Dick sprang from his cockpit as the old man rose in alarm. He ran to him and caught him by the arm.
"Luke Evans!" he cried. "Thank God you've come back in time to save America!"
I
n the Blue Room of the White House the Council listened to old Luke Evans's exposition of his invention with feelings ranging from incredulity to hope.
"I've been at work all the time," said the old man, "not far from here. I knew the day would come when you'd need me. I put my pride aside 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-breaking device that I invented was a heavy, inert gas, invisible, but almost as viscous as paint. Applied to textiles, to inorganic matter, to animal bodies, it adheres for hours. Its property is to render such substances invisible by absorbing all the visible light rays that fall upon it, from red to violet. Light passes through all substances that are 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 means absolute invisibility. It can be shot from this apparatus"—he indicated the box upon the table. "This box contains a minute portion of a gas which exists in nature in the form of a black, crystalline powder. The peculiar property of this powder is that it is the solidified form of a gas more volatile than any that is known. So volatile is it that, when the ordinary atmospheric pressure of fifteen pounds to the square inch is removed, the powder instantly changes to the gaseous condition."
"By pressing this lever"—Evans pointed at the box—"a vacuum is created. Instantly the powder becomes a gas, which shoots forth through this aperture with the speed of a projectile, taking the form of a beam of absolute blackness. Or it can be discharged from cylinders in such a way as to extend over a large area within a few minutes."
"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 gas with which the airships are painted confers invisibility because it absorbs sunlight. But it does not absorb the still more rapid waves, or oscillations which manifest themselves as radio-activity. On the contrary, it gathers and reflects these.
"Now Roentgen, the discoverer of the X-ray, observed that if X-rays are allowed to enter the eye of an observer who is in complete darkness, the retina receives a stimulus, and light is perceived, due to the fluorescent action of the X-rays upon the eyeball.
"Consequently, by creating a beam of complete darkness, I bring into clear visibility the fluorescent gas that coats the airships; in other words, the airships become visible."
"If a light ray is nullified upon entering the field of darkness, will it emerge at the other edge as a perfect light ray again?" asked Stopford.
"It will emerge unchanged, since the black beam destroys light by slightly slowing down the vibrations to a point where they are not perceived 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 to electric waves, and re-converts them into sound waves at the other end, without any appreciable interruption."
"Then," said Stopford, "the logical application of your method is to plunge every city in the land into darkness by means of this gas?"
"That is so, sir, and then we shall have the advantage of invisibility, andthe enemy ships will be in fluorescence."
"Damned impracticable!" muttered Stopford.
"You seriously propose to darken the greater part of eastern North America?" asked the Secretary for War.
"The gas can be produced in large quantities from coal tar besides existing in crystalline deposits," replied Luke Evans. "It is so volatile that I estimate that a single ton will darken all eastern North America for five days. Whereas the concentration would be made only in specific areas liable to attack. The gas is distilled with great facility from one of the tri-phenyl-carbinol coal-tar derivatives."
Vice-president Tomlinson was a pompous, irascible old man, but it was he who hit the nail on the head.
"That's all very well as an emergency measure, but we've got to find the haunt of that gang and smash it!"
An orderly brought in a telegraphic dispatch and handed it to him. The Vice-president opened it, glanced through it, and tried to hand it to the Secretary of State. Instead, it fluttered from his nerveless fingers, and he sank back with a groan. The Secretary picked it up and glanced at it.
"Gentlemen," he said, trying to control his voice, "New York was bombed out of the blue at sunrise this morning, and the whole lower part of the city is a heap of ruins."
I
n the days that followed it became clear that all the resources of America would be needed to cope with the Invisible Empire. Not a day passed without some blow being struck. Boston, Charleston, Baltimore, Pittsburg in turn were devastated. Three cruisers and a score of minor craft were sunk in the harbor of Newport News, where they were concentrating, and thenceforward the fleet became a fugitive force, seeking concealment rather than an offensive. Trans-Atlantic sea-traffic ceased.
Meanwhile the black gas was being hurriedly manufactured. From cylinders placed in central positions in a score of cities it was discharged continuously, covering these centers with an impenetrable pall of night that no light would penetrate. Only by the glow of radium paint, which commanded fabulous prices, could official business be transacted, and that only to a very small degree.
Courts were closed, business suspended, prisoners released, perforce, from jails. Famine ruled. The remedy was proving worse than the disease. Within a week the use of the dark gas had had to be discontinued. And a temporary suspension of the raids served only to accentuate the general terror.
There were food riots everywhere, demands that the Government come to terms, and counter-demands that the war be fought out to the bitter end.
Fought out, when everything was disorganized? Stocks of food congested all the terminals, mobs rioted and battled and plundered all through the east.
"It means surrender," was voiced at the Council meeting by one of the members. And nobody answered him.
Three days of respite, then, instead of bombs, proclamations fluttering down from a cloudless sky. Unless the white flag of surrender was hoisted from the summit of the battered Capitol, the Invisible Emperor would strike such a blow as should bring America to her knees!
I
t was a twelve-hour ultimatum, and before three hours had passed thousands of citizens had taken possession of the Capitol and filled all the approaches. Over their heads floated banners—the Stars and Stripes, and, blazoned across them the words, "No Surrender."
It was a spontaneous uprising of the people of Washington. Hungry, homeless in the sharpening autumn weather, and nearly all bereft of members oftheir families, too often of the breadwinner, now lying deep beneath the rubble that littered the streets, they had gathered in their thousands to protest against any attempt to yield.
Dick, flying overhead at the apex of his squadron, felt his heart swell with elation as he watched the orderly crowds. This was at three in the afternoon: at six the ultimatum ended, the new frightfulness was to begin.
At five, Vice-president Tomlinson was to address the crowds. The old man had risen to the occasion. He had cast off his pompousness and vanity, and was known to favor war to the bitter end. Dick and his squadron circled above the broken dome as the car that carried the Vice-president and the secretaries of State and for War approached along the Avenue.
Rat-tat, rat-a-tat-tat!
Out of the blue sky streams of lead were poured into the assembled multitudes. Instantly they had become converted into a panic-stricken mob, turning this way and that.
Rat-a-tat-tat. Swaths of dead and dying men rolled in the dust, and, as wheat falls under the reaper's blade, the mob melted away in lines and by battalions. Within thirty seconds the whole terrain was piled with dead and dying.
"My God, it's massacre! It's murder!" shouted Dick.
T
hey had not even waited for the twelve hours to expire. To and fro the invisible airplanes shot through the blue evening sky, till the last fugitives were streaming away in all directions like hunted deer, and the dead lay piled in ghastly heaps everywhere.
Out of these heaps wounded and dying men would stagger to their feet to shake their fists impotently at their murderers.
In vain Dick and his squadron strove to dash themselves into the invisible airships. The pilots eluded them with ease, sometimes sending a contemptuous round of machine-gun bullets in their direction, but not troubling to shoot them down.
Two small boys, carrying a huge banner with "No Surrender" across it, were walking off the ghastly field. Twelve or fourteen years old at most, they disdained to run. They were singing, singing the National Anthem, though their voices were inaudible through the turmoil.
Rat-tat! Rat-tat-a-tat! The fiends above loosed a storm of lead upon them. Both fell. One rose, still clutching the banner in his hand and waved it aloft. In a sudden silence his childish treble could be heard:
My country, 'tis of theeSweet land of lib-er-ty—
My country, 'tis of theeSweet land of lib-er-ty—
The guns rattled again. Clutching the blood-stained banner, he dropped across the body of his companion.
Suddenly a broad band of black soared upward from the earth. Those in charge of the cylinders placed about the Capitol had released the gas.
A band of darkness, rising into the blue, cutting off the earth, making the summit of the ruined Capitol a floating dome. But, fast as it rose, the invisible airships rose faster above it.
A last vicious volley! Two of Dick's flight crashing down upon the piles of dead men underneath! And nothing was visible, though the darkness rose till it obliterated the blue above.
A
t dawn the Council sat, after an all-night meeting. Vice-president Tomlinson, one arm shattered by a machine-gun bullet, still occupied the chair at the head of the table.
Outside, immediately about the White House, there was not a sound. Washington might have been a city of the dead. The railroad terminals, however, were occupied by a mob of people, busily looting. There was great disorder. Organized government had simply disappeared.
Each man was occupied only with obtaining as much food as he could carry, and taking his family into ruraldistricts where the Terror would not be likely to pursue. All the roads leading out of Washington—into Virginia, into Maryland, were congested with columns of fugitives that stretched for miles.
Some, who were fortunate enough to possess automobiles, and—what was rarer—a few gallons of gas, were trying to force their way through the masses ahead of them; here and there a family trudged beside a pack-horse, or a big dog drew an improvised sled on wheels, loaded with flour, bacon, blankets, pillows. Old men and young children trudged on uncomplaining.
The telegraph wires were still, for the most part, working. All the world knew what was happening. From all the big cities of the East a similar exodus was proceeding. There was little bitterness and little disorder.
It was not the airship raids from which these crowds were fleeing. Something grimmer was happening. The murderous attack upon the populace about the Capitol had been merely an incident. This later development was the fulfilment of the Invisible Emperor's ultimatum.
Death was afield, death, invisible, instantaneous, and inevitable. Death blown on the winds, in the form of the deadliest of unknown gases.
I
n the Blue Room of the White House a score of experts had gathered. Dick, too, with the chiefs of his staff, Stopford, and the army and naval heads. Among them was the chief of the Meteorological Bureau, and it was to him primarily that Tomlinson was reading a telegraphic dispatch from Wilmington, South Carolina:
"The Invisible Death has reached this point and is working havoc throughout the city, spreading from street to street. Men are dropping dead everywhere. A few have fled, but—"
The sudden ending of the dispatch was significant enough. Tomlinson picked up another dispatch from Columbia, in the same State:
"Invisible Death now circling city," he read. "Business section already invaded. All other telegraphists have left posts. Can't say how long—"
And this, too, ended in the same way. There were piles of such communications, and they had been coming in for eighteen hours. At that moment an orderly brought in a dozen more.
Tomlinson showed the head of the Meteorological Bureau the chart upon the table. "We've plotted out a map as the wires came in, Mr. Graves," he said. "The Invisible Death struck the southeast shore of the United States yesterday afternoon near Charleston. It has spread approximately at a steady rate. The wind velocity—?"
"Remains constant. Seventy miles an hour. Dying down a little," answered Graves.
"The death line now runs from Wilmington, South Carolina, straight to Augusta, Georgia," the Vice-president pursued. "Every living thing that this gas has encountered has been instantly destroyed. Men, cattle, birds, vermin, wild beasts. The gas is invisible and inodorous. These gentlemen believe it may be a form of hydrocyanic acid, but of a concentration beyond anything known to chemistry, so deadly that a billionth part of it to one of air must be fatal, otherwise it could not have traveled as it has done. Warnings have been broadcasted, but there are no stocks of chemicals that might counteract it. Flight is the only hope—flight at seventy miles an hour!"
H
is voice shook. "This gas has been loosed, as you told us, upon the wings of the hurricane that came through the Florida Strait. What are the chances of its reaching Washington?"
"Mr. Vice-president, if the wind continues, and this gas has sufficient concentration, it should be in Washington within the next eight hours." Graves replied. "If the wind changes direction, however, this gas will probably be blown out to sea, or into the Alleghanies, where it will probably be dissipated among the hills, or by the foliage on the mountains. I'm not a chemist—"
"No, sir, and I am not consulting you as one," answered old Tomlinson. "A death belt several hundred miles in length and three or four hundred deep has already been cut across this continent. We are faced with wholesale, unmitigated murder, on such a scale as was never known before. But we are an integral part of America, and Washington has no more right to expect immunity than our devastated Southern States. The question we wish to put to you is, can you trace the exact course taken by the hurricane?"
"I can, Mr. Vice-president," answered Graves. "It originated somewhere in the West Indian seas, like all these storms. We've been getting our reports almost as usual. Our first one came from Nassau, which was badly damaged. The storm missed the Florida coast, as many of them do, and struck the coast of South Carolina—in fact, we received a report from Charleston, which must have almost coincided with your first report of the gas."
"If the storm missed the Florida coast, it follows that the gas was not discharged from any point on the American continent," said Tomlinson. "From some point off Florida—from some island, or from a plane or from a ship at sea."
"Not from a ship at sea, Mr. Vice-president," interposed the head of the Chemical Bureau. "To discharge gas on such an extensive scale would require more space than could be furnished by the largest vessel, in my opinion."
"In all probability the gas was 'loaded,' so to say, onto the gale somewhere in the Bahamas," said Graves. "That seems to me the most likely explanation."
V
ice-president Tomlinson nodded, and picked up one of the latest telegraphic dispatches, as if absently.
"Gentlemen," he said, "the Invisible Death has already reached Charlotte."
He picked up another. "Reported Abaco Island, Bahamas, totally wrecked by storm. All communication has ceased," he read. He turned to Dick and spoke as if inspired. "Captain Rennell, there is your destination," he thundered. "They've betrayed themselves. We've got them now. You understand?"
"By God, sir! It's from Abaco Island, then, that those devils have been carrying on their game of wholesale murder!"
Suddenly a contagion of enthusiasm seemed to sweep the whole assemblage. Every man was upon his feet in an instant, white, quivering, lips opened for speech that trembled there and did not come.
It was Secretary Norris spoke. "The Vice-president has hit the mark," he said, with a dramatic gesture of his arm. "Yes, they've betrayed themselves. Their headquarters are on Abaco Island. It's one of the largest in the Bahamas." He turned to the Secretary for the Navy. "You can rush the fleet there, sir?" he asked.
"Within forty-eight hours I'll have every vessel that can float off Abaco Island."
"I'll concentrate all airplanes. Take your flight, Captain Rennell. We'll stamp out that nest of murderers if we blow Abaco Island to the bottom of the sea. It can be done!"
"It can be done, sir—with Luke Evans and his invention," answered Dick.
T
hree hours later, about the time when the war council rose after completing its plans, a sudden shift of the wind blew the poison gas out tosea, just when it appeared certain that it would reach the capital of the nation.
The southern half of Virginia had been swept over. Operators, telegraph and telephone, staying at their posts had sent in constant messages that had terminated with an abruptness which told of the tragic sequel. Yet, at that distance from its source, the intensity of the gas had been to some extent dissipated.
Poisonous beyond any gas known, so deadly as to make hydrocyanic gas innocuous in comparison, still as it was swept northward on the wings of the wind, there had been an increasing number of non-fatal casualties. The most northernly point reached by the gas was Richmond, and here some fifty per cent of those stricken had suffered paralysis instead of death.
But a new element had been injected into the situation. Even the heroic courage shown by the populace in the beginning had had its limits. The morning after the news of the Invisible Death's advent was made public mobs had gathered in all the large cities of the East, demanding surrender.
The submerged elements of crime and disorder had come to the surface at last. Committees were formed, with the avowed object of yielding to the Invisible Emperor, and averting further disaster. In Washington, a city of the dead, half the members of Congress and the Senators had gathered in the ruined Capitol, to debate the situation.
There were rumors of an impending march on the White House, of a coup d'ètat.
T
he action of the Government was prompt. Five hundred loyalists were enrolled, armed, and posted round the White House: every avenue of approach was commanded by machine-guns. Meanwhile the news was spread by radio that the headquarters of the Invisible Emperor had been located, and that a strong bombing squadron was being dispatched to destroy it.
The entire fleet was to follow, and it was confidently anticipated that within a little while the Terror would be at an end.
Those at the white House were less sanguine. There was none but realized the diabolical strength of their antagonists.
"Everything depends upon the outcome of the next forty-eight hours, and everything depends on you, Rennell," said Secretary Norris to Dick, as he stood beside his plane. Behind him his flight of a dozen airships was drawn up.
"Find them," added the Secretary; "cover Abaco Island with the black gas, and the navy and the marines will wipe up the mess that you leave behind you. God help you—and all of us, Rennell!"
He gripped Dick's hand and turned away. Dick was very sober-minded as he climbed into his cockpit. He knew to the full how much depended upon himself and Luke Evans. Already the shouts of the insurgents were to be heard at the ends of the barriers, commanded by the machine-guns, and patrolled by the enlisted volunteers.
Negro mobs were building counter-barricades of their own with rubble from the fallen edifices. Civil war might be postponed for eight-and-forty hours, but after that unless there was news of victory, the whole structure of civilization would be smashed irreparably.
It was up to Dick and Luke Evans, and they had assumed such a responsibility as rarely falls to the lot of man in war.
D
ick was to lead the flight in a two-seater Barwell plane. This was one of the latest types, and had been hurriedly adapted to the purpose for which it was to be used. Dick himself occupied the rear seat, with its dual controls, and the gun in its armored casing. In front sat old LukeEvans, in charge of the black gas projector.
His famous camera box, containing a minute quantity of gas in slow combustion, and projecting the black searchlight, had been built into the plane. In the rack beside him were a number of the black gas bombs, each of which, dropped to earth, would release enough gas to cover a considerable area with darkness. Both Luke and Dick wore respirators filled with charcoal and sodium thio-sulphate, and beside Dick a cage containing three guinea-pigs rested.
These little rodents were so sensitive to atmospheric changes that a quantity of hydrocyanic acid too minute to affect a man would produce instantaneous death on them.
From its hiding-place off the Virginia coast the American fleet was steaming hotly southward toward Abaco Island, cruisers, destroyers, submarines. That Abaco was British territory had simply not been considered in this crisis of history.
The twelve airships that followed Dick's contained enough bombs to put the headquarters of the Invisible Empire out of business for good. The naval guns would complete the same business.
All day Dick and Luke Evans flew southwestward. At first glance, everything appeared normal. The catastrophe that had fallen upon the land was visible only in the shape of the lines of tiny figures, extending for miles, that choked all the roads radiating out of the principal cities. It was only when they were over the southern portion of Virginia that the ravages of deadly gas became apparent.
Flying low, Dick could see the fields strewn with the bodies of dead cattle. Here and there, at the doors of farmhouses, the inmates could be seen, lying together in gruesome heaps, caught and killed instantaneously as they attempted flight. Here, too, were figures on the roads. But they were figures of dead men and women.
T
hey strewed the roads for miles, lying as they had been trapped—men, women, children, horses, mules, and dogs. The spectacle was an appalling one. Dick set his jaws grimly. He was thinking that the Council had let Von Kettler escape. He was thinking of Fredegonde. But he would not let himself think of her. She deserved no more pity than the rest of the murderous crew.
Over the Carolinas the conditions were still more appalling. Here deadly gas had struck with all its concentrated power. A city materialized out of the blue distance, a factory town with all chimneys spiring upward into the blue, a section of tall buildings intersected by canyonlike streets, around it a rim of trim houses, bungalows, indicative of prosperity and comfort. And it was a city of the dead.
For everywhere around it, on all the roads, the dead lay piled on top of one another. For miles—all the inhabitants, rich and poor, business men, factory hands, negroes. There had been a mad rush as the fatal gas drove onward upon its lethal way, and all the fugitives had been overwhelmed simultaneously.
Here were golf links, with little groups strewn on the grass and fairways; here, at one of the holes, four men, their putters still in their hands, crouched in death. Here was the wreckage of a train that had collided with a string of freight cars at an untended switch, and from the shattered windows the heads and bodies of the dead protruded in serried ranks.
Dick looked back. His flight was driving on behind him. He guessed their feelings. They had sworn, as he had sworn, that none of them would return without stamping out that abomination from the earth forever.