WITHOUT even pausing to see the effects of his charge upon the three air-ships above Alexandria, Alan kept the Avenger going at full speed, soaring up into the higher regions of the atmosphere with her prow pointed to the north-east. About three hours later she was floating at an elevation of nearly five miles above Moscow, not stationary, but sweeping round and round in vast circles on her quadruple wings after the manner of the condors of the Andes, which thus sustain themselves on almost motionless wings at vast elevations and very small expenditure of force.

Below an immense expanse of country lay in unclouded clearness under the glasses of the captain of the ship and George Cosmo, late engineer of the Narwhal, who was now chief engineer of the Aerian flagship.

Not only Moscow, but a dozen other towns lay at the mercy of the Avenger’s twenty-four guns, and yet no shot was fired, for Alan, despite the tremendous debt of vengeance that he owed to her who now, at last in very fact crowned Tsarina of the Russias, held her court at Moscow, was yet extremely loth to involve non-combatants in the destruction which he knew must follow the discharge of his guns.

Added to this, his present designs were rather to reconnoitre than to destroy. He was in command of the fastest and most powerful air-ship in the world, and the task that he had set himself was to supervise the whole of the complicated arrangements that had been made for repelling the coming attack upon the Federation by the Moslems and Russians.

Thus he had started soon after midnight from Gibraltar, one of the chief power-stations and depÔts in Europe. Thence he had run along the African coast over Oran, Algiers, Tunis, and Tripoli, noting the sleepless activity of the brilliantly-lighted towns, the swarming transports and battleships in their harbours, and the crowds of anxious watchers in their streets. Then he had got round to the south of Alexandria, as has been seen, and there struck the first blow in the war.

Now, his object was to discover what disposition of troops were being made for the invasion of Austria and Germany. Another scout-ship would be by this time floating over St. Petersburg, and another over Odessa, and these were to report to him at noon.

He had kept the Avenger moving with sufficient rapidity to make it extremely difficult for her to be seen from the earth, as he wanted to see without being seen, and he remained undiscovered until nearly noon. All this time trains had been seen running in swift succession into Moscow from the east and out to the west, evidently conveying troops to the frontier.

A large fleet of air-ships, numbering apparently between two and three hundred vessels, were seen lying in four squadrons on the open space about the Kremlin, and others were constantly flying into and out of the city in all directions.

A few minutes after half-past eleven, Cosmo, after a long look through his glasses, called to Alan, who was looking out from the other side of the deck—

“I fancy they must have seen us at last. Three ships are coming up on this side as if they wanted to investigate.”

Alan crossed over and soon picked out the Russian vessels rising in long spiral sweeps from the earth about three miles to the northward and coming up very fast.

“They seem to have learned something in tactics during the year,” he said. “They evidently know better than to rise perpendicularly while they suspect we are up here. They think they’ll be much more difficult to hit coming up like that.”

“Yes,” said Cosmo. “But we can soon show them the mistake in that idea. What are you going to do with them?”

“Destroy them, of course,” replied Alan. “It doesn’t matter about giving the alarm now. I think it’s pretty certain that the Russians are going to concentrate at Kieff, Vitebsk, DÜnaburg, and Vilna, and those four squadrons down there are intended to cover them. We’d better let them concentrate, and make the fighting as short and sharp as possible. It would be a waste of time to destroy them here in detail, and the moral effect wouldn’t be anything like as good. What do you think?”

“I don’t think there’ll be any fighting,” replied Cosmo, “unless between the air-ships. The most hardened troops of the nineteenth century would have broken and run like a lot of sheep under our shells, and these poor fellows, who have never seen a battle in their lives, will do the same.

“I don’t believe we shall have any land fighting at all to speak of during the whole war. There will be nothing but massacres from the air on both sides. Still, I think you’re both wise and merciful in waiting until you can hit hard, though perhaps from the strictly military point of view we ought to have Moscow in ruins by sundown.”

“I won’t do that,” said Alan, shaking his head decisively. “There are three or four millions of women and children in it who have done no harm, and I’ll shed no more blood than I’m obliged to. We had better destroy those fellows, however, before they get too close. You know what to do.”

“Very well,” said Cosmo. “You’ll take the deck, I suppose?”

Alan nodded, and Cosmo saluted and went into the conning-tower. The Avenger now altered her course, so that her circling flight took her to the northward, above the three Russian air-ships that were sweeping round and round so fast that it would have been impossible to train a gun upon them.

As soon as she got over them the Avenger quickened her course until she was flying round in the same circles and at the same speed as the Russians. This, of course, made her relatively stationary with regard to them, and it was now possible to take aim. Two of the broadside guns, one on each side, were much shorter than the others, and had been specially constructed for firing almost vertically downwards.

Alan stood by one of these and trained it on the first of the Russian vessels, which were coming up in a spiral line. At the right moment he pressed the button in the breech and released the projectile. The shot struck the Russian amidships. They saw the glass deck of the roof splinter, then the blaze of the explosion flashed out, the air quaked, and the next moment the fragments of the Russian warship were falling back upon the earth.

A second and a third shot followed as the other two came into position, and when Alan looked down towards the city again he saw that the four squadrons had taken the alarm, and were rising from the earth and scattering in all directions. This was just what he wanted, for it relieved him of the scruples which had prevented him from firing on them while they lay within the precincts of the city.

In an instant the crew of the Avenger were at their guns, and shell after shell sped on its downward way after the flying ships. Although, under the circumstances, the aim was necessarily hurried, for the captains of the Russian vessels, seeing the terrible disadvantage at which they were placed, had put on their utmost speed, the guns of the Avenger were so smartly handled that nearly a score of the Russians were either blown to fragments or crippled before the squadron escaped out of range.

“Well done!” said Alan. “That will teach them to keep a little smarter look-out next time.” And then he went on to himself—“I wonder whether she was on board one of those that are lying in little pieces down there? I suppose that would be too good luck to hope for, and yet I don’t know, I think her end ought to be something different to that. I wonder what it really will be?”

He ordered his men to cease firing now, and placed the Avenger once more in her old position over Moscow, keeping her at a great elevation to guard against surprise from the squadron he had scattered. A few minutes later two air-ships were reported coming from the south and north. The flash of the sun on their blue hulls proclaimed them friends.

They were the vessels bringing the reports from St. Petersburg and Odessa, and these reports were to the effect that during the whole of the morning trains had been pouring through from the eastward and all the surrounding country towards the Austro-German frontier. Other reports from the westward had been received by the commanders of these two vessels to the effect that the Russian troops were massing along the frontier and seemingly preparing to invade the Federation area from the four points already selected by Alan.

He at once despatched orders by these two courier-vessels to the depÔts at KÖnigsberg, Thorn, Breslau, and Budapesth to assemble four squadrons of fifty vessels each, which were to be over the points of concentration at daybreak on the following morning.

These ships were to maintain their greatest possible elevation—that is to say, about three miles and a half—until the sun rose, then if the sky were clear they were to bombard the towns at once from that height; if not they were to use all precautions against surprise in passing through the clouds, and then the commanders were to use their own discretion as to the plan of operation, but Odessa, Kieff, Vitebsk, and DÜnaburg were to be destroyed at all hazards as soon as it was certain that the invading forces were concentrated there, and preparing to march eastward.

As soon as these orders had been despatched the Avenger left Moscow, and started at full speed for Gibraltar, where she arrived about four o’clock in the afternoon.

Here Alan, after once more inspecting the land batteries and the aerial defences of this important outpost of the Federation, received news of the annihilation of the four Moslem expeditions, and heartily congratulated Admiral Ernstein on the complete success of his operations.

It was at once apparent that the Sultan would not risk a second loss so enormous as this even if he had sufficient transports left and could persuade any more of his people to brave the terrors of such another sea-fight. This being so, only two alternatives would be open to him, either he must give up all idea of invading Europe by land or sea, or else he must attempt to force the bridges across the Dardanelles and the Straits of Gibraltar, and cross into Europe vi Turkey and Spain.

Both these bridges, the main highways between Europe, Africa, and Asia Minor, were guarded on the European side by batteries of enormous strength, similar to those which guarded the Federation posts in the Mediterranean. They were magnificent structures, each four hundred feet broad, carrying twelve lines of railway as well as carriage drives and promenades, and, once in the hands of the enemy, troops could be poured across them in tens of thousands every hour.

Alan, after a brief conference with Ernstein, decided to pursue the same tactics here as he was going to make use of on the Russian frontier. The bridges were to be left completely open, but their supporting pillars were to be mined with torpedoes, connected by electric wires with the batteries.

If the Sultan attempted to force them, his men were to be allowed to concentrate on the African and Asiatic shores and to occupy the bridges, then the bridges were to be blown up and the forces on the opposite side to be dispersed by the batteries and the air-ships.

The message to the Dardanelles bridge was despatched by telephone over the cables connecting Gibraltar with Candia and Gallipoli, and similar instructions were sent on from Gallipoli to Constantinople, in case any attempt should be made to force the bridge which spanned the Bosphorus.

The Mediterranean patrol was to be maintained as before, and three air-ships were sent out to reconnoitre the African coast from Ceuta to Port Said during the night, and learn what they could of the Sultan’s intentions.

The rest of the evening and the greater part of the night were spent by Alan receiving and answering reports from the northern coast of the Mediterranean, the Russian frontier, and the principal cities of Europe, and in assuring himself that everything was ready, so far as was possible, to meet the storm that must infallibly burst over the Continent within the next few days.

What would have been in the nineteenth century a matter of weeks was now only one of days and hours. The enormously-developed system of intercommunication made transit, even for very large numbers of men and between very distant points, rapid to a degree undreamt of in the present century.

Trains could travel at two hundred miles an hour along the hundreds of quadruple lines which covered the Continent with their gigantic network, aerial cruisers could fly at more than twice this speed, and squadrons of submarine battleships could cleave their silent and invisible way through the ocean depths at a hundred and fifty miles an hour.

It was, therefore, almost impossible to tell without certain information where and how the blows of the enemy would be struck, or from how many points the European area of the Federation might be assailed at once, and vast indeed were the responsibilities and anxieties which weighed upon the man whose single brain was the centre of this vast and complicated system of defence, and on whose decisions would depend the safety or the destruction of millions of human beings.

Alan had managed to get four hours’ sleep in the afternoon between Moscow and Gibraltar, and he snatched two hours more before midnight. Then he was called, and the Avenger was just about to take the air to return to the Russian frontier, so that he might supervise the operations there, when the look-out on the summit of the Rock of Gibraltar saw and answered the Aerian private signal from the sky, and a few minutes later a fleet of more than a hundred air-ships dropped down out of the darkness and hovered over what is now called the neutral ground between the Rock and Spain.

One of these alighted at the signal station itself. It was the Isma, and within three minutes after she had touched the ground Alan was shaking hands with Alexis and asking him what brought him back so soon from the East.

“I have come back because there is nothing much more to do there,” said Alexis. “Have you had any fighting here?”

“Yes,” said Alan; “or, at anyrate, a big massacre.”

And then he described what had befallen the Sultan’s expeditions.

“Horrible but necessary, I suppose!” replied Alexis, not without a shudder at the news. “I have been doing my damage on land. I didn’t wait for the enemy to begin hostilities, so as soon as day broke we got to work. We have wrecked Ekaterinburg, Slatonsk, Orenburg, and Uralsk, and blocked the four roads into Russia from Asia.

“The Tsarina’s Asiatic forces had concentrated there in large numbers ready to come into Europe. We found some air-ships intended to cover them, but we had the best of the elevation, and smashed them up. The slaughter has been something perfectly frightful. I had a hundred and fifty ships in action, and there isn’t a man left of the Asiatic troops that is not getting back to where he came from as fast as he can go.

“The towns are mere heaps of ruins and the railways utterly useless. I left twenty ships to patrol the frontier and stop any further movements into Russia, and twenty more are strung out in a line from the Caspian to the head of the Red Sea to cut communications between Asia and Africa.

“We came westward over Odessa this afternoon, and had a skirmish, in which, I am sorry to say, I lost five ships, but we destroyed twenty Russians, blew up the dockyard, and shelled the city by way of punishment. And now I’ve got myself and a hundred and thirty ships to place at your disposal for the present. There is nothing more to be feared from the East, for by to-morrow night, I think, the Asiatics will be thoroughly terrorised.”

“You have done more than I have in the way of slaughter and destruction,” said Alan. “But there will be some fearful work along the Russian frontier to-morrow morning. The Tsarina, as you call her, is concentrating her forces at Kieff, Vitebsk, DÜnaburg, and Vilna for a descent upon Germany. I have ordered those four places to be destroyed as soon as possible after sunrise, and I am just starting now, so you had better come with me and order your ships to follow us.”

Both the commanders felt, as their combined squadrons were winging their way towards the Russian frontier, that the events of the next twenty-four hours or so would go far towards deciding the issues of the war, and therefore the fate of the world.

Alexis had given up the command of the Isma for the night to his first lieutenant, and was travelling on board the Avenger, in order that he and Alan might finally arrange their plans for the terrible deeds that were to be done on the following day. Both of them were serious almost to depression, for it must be remembered that neither possessed that love of fighting and slaughter which distinguishes the professional soldier of the nineteenth century.

Armed with the most awful weapons ever wielded by human hands, they had already, within the space of a few hours, hurled millions of their fellow-creatures into eternity and made thousands of homes desolate which a couple of days ago were happy. Now they were going to repeat the tragedy, on how vast a scale neither of them knew. Before the next sunset a red line of blood and flame would mark the frontier between Russia and Germany.

All the horrors of months of the older warfare would be concentrated into those few fatal hours. Those who were to do battle in the air would hurl their irresistible lightnings at each other more as gods than as men, while on earth the unresisting swarms could only stand in helpless agony of suspense waiting for the death from which there was no possibility of flying.

Within a hundred miles of the frontier the two fleets stopped, and Alexis went on board his own vessel. It was then a few minutes after three in the morning, that is to say, about an hour before sunrise, and the warships were floating in a serene and cloudless atmosphere at an elevation of nearly four miles, or about twenty thousand feet. It was already quite light enough at that elevation for signals to be plainly seen, and a rapid interchange of these took place, communicating the final instructions from the flagships to the commanders of the smaller squadrons into which the fleets were to be divided.

Just as the last signal had been answered, and the vessels were about to separate, a tiny speck of light was seen far away to the westward. A hundred powerful field-glasses were instantly turned upon it, and soon showed it to be a hostile air-ship coming up very fast at an elevation of about three miles. The silvery sheen of her hull instantly betrayed the fact that she was neither an Aerian nor a Federation vessel, for the former were blue and the latter painted dull grey. A moment’s reflection showed that she must have sighted the Aerian fleet, and if she got past would take tidings of its presence to the frontier and destroy all hope of a surprise.

Within twenty seconds of her true nature being made out a signal was flying from the mizzenmast of the Isma, which read, “Shall I stop her?” “Yes. Cripple her if you can. Don’t fire unless necessary,” came the reply from the Avenger, and the Isma at once darted away on her errand.

Alexis, of course, understood that if he struck the enemy with a shell her fragments would fall to the earth, and might probably give the impression that a battle was being fought in the air, and, as they were now so near to the Russian frontier, this was to be avoided if possible. He therefore determined to cripple her without destroying her, and, if he could manage it, to capture her in mid-air, a feat that had never been performed before under similar conditions.

He descended until the Isma was only floating about a thousand feet higher than the enemy, and then began to fly round and round in a wide circle, at a speed which made it practically impossible for her to be hit with a shell, save by the merest chance. The stranger, on sighting the fleet, slowed down and swung round to the northward, so as to have the advantage of being able to present her stern chasers to the enemy.

This gave Alexis the opportunity he wanted. The instant that her stern was visible, the Isma swooped down, and rushed at her at such a speed that she looked more like a stream of blue light flashing through the sky than a solid material body. Those on board her saw this flash dart past their stern. Their ship shivered from stem to stern with some shock that came so swiftly that not until the Isma was almost out of sight did they realise the damage that had been done.

The ram of the Aerian had cut through the barrels of the two stern guns and the shafts of the three propellers as cleanly as a razor would have divided so many straws. Sustained and propelled only by her wings, she dropped from two hundred miles an hour to about twenty-five, and then the Isma reappeared in the sky above her, flying the signal, “Will you surrender?”

Her commander saw that the brilliant and almost miraculous manoeuvre of the Isma had placed him utterly at her mercy. If he refused, a single shell would send him and his ship and crew in fragments to the earth, while none of his guns could touch the Aerian, floating as she did a thousand feet above him, so he bowed to necessity and sent the white flag to his masthead. Alexis then signalled again, ordering him to unload all his guns and leave the breeches open, and when he had seen this done he sank down to a level with her, passed a steel-wire rope on board her, and towed her away in triumph to the fleet.

The brilliant achievement delighted the Aerians as much as it confounded the crew of the captured vessel, especially when it was discovered that she was the Haroun, a Moslem warship taking a message from the Sultan to the Tsarina at Moscow.

Khalid’s letter, which had been despatched the night before from Algiers, informed Olga of the disaster that had overtaken the Crescent in the Mediterranean, and of his determination to avenge it by storming the bridges of Gibraltar, the Dardanelles, and the Bosphorus, and pouring his remaining troops over them into Europe as soon as he could concentrate them.

Far more important than this, however, was a notification of his intention to at once lead a fleet of two hundred and fifty air-ships to the west of Europe, and there destroy city after city on his eastward course until they joined forces and proceeded, if necessary, to devastate the rest of the Continent.

The Moslem’s guns were now rendered useless, and she was left to her own devices to fall an easy prey to the first enemy that might attack her. The Aerian fleet then divided into fifty squadrons of five vessels each, and these winged their way towards the Russian frontier, ever soaring higher and higher, until their wings were beating the rarefied air at an altitude of over three miles.

Odessa, Kieff, Gomel, Vitebsk, DÜnaburg, and Riga were all covered by the time the sun rose. Scores of Russian air-ships were seen by the various squadrons darting about hither and thither along the frontier at varying elevations, evidently on the look-out for an enemy.

It was not many minutes before the Aerian squadrons were discovered by these, and they instantly got away out of range, and then swerving round sought to rise to a similar altitude so as to place themselves on equal terms with the Aerians.

But long before this attempt could be made the work of death had begun, and two thousand guns were raining their projectiles, charged with inevitable destruction, upon the devoted cities. They were swarming with men who had come through the interior of Russia during the night for the invasion of Europe, but there were no troops on land to oppose them, for Alan had seen that there would be no need for these.

Within an hour the six cities were so many vast shambles, and still the relentless rain of death kept falling from the skies. Houses and public buildings crumbled into dust under the terrific impact of the explosions.

The streets were torn up as if by earthquakes, the railways running in and out were utterly wrecked, and the victims of the pitiless attack, panic-stricken and mad with fear and agony, rushed aimlessly hither and thither through the bloody, fire-scorched streets and amidst the falling ruins until inevitable death overtook them and ended their tortures of mind and body.

There was no escape even as there was no mercy. Thousands fled out into the country only to find the same rain of death falling upon the villages. It seemed as though the unclouded heavens of that May morning were raining fire and death from every point upon the devoted earth, and yet no source of destruction was to be seen.

But ere long new horrors were added to the desolation which had already befallen the cities. Terrific explosions burst out high up in the air, vast dazzling masses of flame blazed out, mocking the sunlight with their brightness, and then vanishing in an instant, and after them came showers of bits of metal and ragged fragments of human bodies, all that remained of some great cruiser of the air and her crew.

The Russian squadrons, numbering in all about three hundred warships, by flying several miles to the eastward and then doubling on a constantly ascending course had by this time gained a sufficient elevation to train their guns upon the Aerians, and as soon as they had done this the aerial battle became general along a curved line more than a thousand miles in length, extending from Odessa to Riga.

George Cosmo had been right when he said that there would be little or no land fighting, for along that line, from the Baltic to the Black Sea, there was scarcely a man left alive by midday who was not mad with fear and horror at the frightful effects of the aerial assault.

On land as well as on sea fighting was impossible. Armies and fleet could exist only in the absence of the air-ships, and they were everywhere. Cities lay utterly at their mercy, and nothing shaped by the hand of man could withstand the impact of their projectiles.

But all day long the fight went on in the skies above the Russian frontier, yet not at all after the fashion imagined by the poet of the nineteenth century, who wrote, as he thought prophetically, of

Airy navies grappling in the central blue.

The first and chief endeavour of the captain of every vessel was to avoid the shots of his opponents and to get his own home. It was brains and machinery pitted against brains and machinery, and grappling was never thought of.

The air-ship which could gain and maintain a greater elevation than her opponent infallibly destroyed her, and so, too, did the one that could fly unhurt at full speed along the line of battle and use her stern guns upon those which became relatively stationary enough for her to take aim at them.

It would have been a magnificent spectacle for an observer who could have followed the contending squadrons in their swift and complicated evolutions. He would have seen the blue and the silver hulls flashing to and fro as though apparently engaged in some harmless trial of speed, then, without the slightest warning, without a puff of smoke or the faintest sound of a report, the long, deadly guns would do their work.

The moment of vantage would come, and the silent and invisible messengers of annihilation would be sped upon their way; then, with a roar and a shock that convulsed the firmament, a mist of flame would envelop the ship that had been struck, and when it vanished she would have vanished too, falling in a rain of fragments towards the earth nearly twenty thousand feet below.

It was a battle not so much for victory as for destruction. There could be no victory save to those who survived after having annihilated their enemies, and this was the sole object of the struggle. High in air above the contending squadrons, the Avenger and the Isma swept to and fro along the line, raised by their superior soaring powers beyond the zone of battle, and from their decks the two admirals commanded the fight, and, like very Joves above the tempest, hurled their destroying bolts from their terrible guns far and wide over the scene of strife.

From morning to night both Alan and Alexis sought in vain for the blue hull of the Revenge among the Russian squadron. Unless Olga was on board one of the other ships she was either engaged in some work of destruction elsewhere or was directing the operations of her forces and learning the disasters that had overtaken them in her palace in Moscow or St. Petersburg.

It had been previously ordered that, as soon as it became too dark to take accurate aim with the guns, those vessels of the Aerian fleet which had survived the battle were to fly westward and rendezvous at midnight on the summit of the Schneekoppe, one of the peaks of the Giant Mountains to the north-east of Bohemia, whence, as soon as the amount of damage had been ascertained, the remainder of it, if strong enough, was to set out and if possible intercept the Moslem fleet before it could form a junction with the Russians.

When the last vessel had alighted on the summit of the mountain it was found that out of a fleet numbering two hundred and fifty warships only a hundred and eighty remained—the rest were scattered in undistinguishable fragments along the Russian frontier. As for the amount of damage that had been done to the enemy as a set-off to this heavy loss, the Aerian commanders could form no even approximate estimate of it.

All they knew was that the six frontier cities, and a score or so of smaller towns and villages, were now mere heaps of ruins, vast charnel-houses choked with unnumbered corpses. The Russian army of invasion must have been practically annihilated, and certainly its remnants would be too hopelessly demoralised by the unspeakable horrors it had survived to be of the slightest use for further fighting.

As soon as the roll had been called, the fleet, in two squadrons of ninety vessels each, took the air and crossed the mountains to Gorlitz, which had been selected a year before as a convenient spot for the establishment of an arsenal and power-station, standing as it does at the angle of intersection of two great mountains which form the natural bulwarks of Bohemia.

Here the stock of motive-power and the ammunition of all the vessels were renewed, and at daybreak the squadrons were just about to take the air when a telephonic message was received from Paris that a large fleet of air-ships had appeared above the city and had begun to bombard it. This message had been sent in compliance with a system of intercommunication which Alan had instituted between all the great cities of Europe, and all the power-stations and rendezvous throughout the Continent.

The moment an enemy appeared over any town messages were to be sent to all the stations simultaneously, and detachments of warships were to be despatched to the threatened point as soon as the warning was received.

It will be seen that this system would enable a very large force to be concentrated upon any threatened point, and, in fact, before the sun was two degrees above the horizon of Paris, eight squadrons of Federation warships, including the two under the command of Alan and Alexis, were flying at full speed from all four points of the compass towards the city which for over half a century had been the acknowledged capital of the Continent.

Little more than an hour sufficed for the Avenger and the Isma to pass over the six hundred miles which separated Gorlitz from Paris. Flying at their utmost speed they left their squadrons to follow the two admirals, knowing that every captain could be implicitly trusted to do the work allotted to his ship without further orders.

The object of Alan and Alexis was to get first to the scene of action, and to avail themselves of the superior soaring powers of their two vessels to deliver an assault upon the Moslems which they could not reply to.A fearful scene unfolded itself before them as they swept up out of the eastward over Paris. The vast and splendid city was surrounded by a huge circle formed of at least two hundred Moslem warships floating at an elevation of some three miles, and pouring a tempest of projectiles from hundreds of guns indiscriminately into the area crowded with stately buildings and nearly ten millions of inhabitants.

Nearly three miles above the centre of the city floated a solitary scout-ship ready to signal warning of the approach of an enemy. Fires were already raging in hundreds of places all over the city. The streets were swarming with terrified throngs of citizens who had rushed out to escape the flames and the falling buildings, only to meet the hundreds of shells that were constantly bursting among them, rending their bodies to fragments by scores at a time.

Such was the beginning of Khalid the Magnificent’s revenge for the disaster of the Mediterranean—a vengeance which proved that, in his breast at least, the savage spirit of the ancient warfare was still untamed.

The Avenger and the Isma gained an altitude of four miles above the doomed city, half a dozen shells from their guns struck the scout-ship and reduced her to dust before she had time to make a signal in warning, and then the forty-four guns began to send a radiating hail of projectiles upon the Moslem fleet. Shell after shell found its mark in spite of the vast range, and ship after ship collapsed and dropped in fragments or blew up like a huge shell.

But before the fifth round had been fired a strange thing happened. A single Aerian warship rushed up at full speed out of the south, and as soon as she sighted the Avenger signalled, “Orders from the Council. Come alongside.” The new-comer soared upwards as they sank to meet her, and the three ships met and stopped some three miles and a half above the earth. The stern of the Azrael, as the messenger-ship was named, was brought close up to that of the Avenger, the deck doors were opened, a gangway thrown across, and the captain boarded the flagship and placed a sealed despatch in Alan’s hand.

He opened it, and to his unspeakable astonishment read—

Aeria, May 16th, 6 P.M.

All Aerians are to return at once with their ships to Aeria, and take no further part in the fighting. The Federation fleets may be left in the hands of foreign crews and commanders, to whom the power-stations and batteries are to be given up. This order is to be obeyed with the least possible delay.

Alan Arnold, President.

To the Admirals in command of the Federation Fleets.