BY the 30th of July the work in the caverns was so far advanced that the Council was able to authorise the departure of Alan and his companions for the outside world. The great vertical sluice-door, a huge sheet of steel forty feet long, twenty wide, and eighteen inches thick, and footed with a great indiarubber pad, was in its place, suspended at the top of the steel-lined grooves, which had been sunk three feet into each of the rock walls of the chasm into which the water-tunnel from the lake opened.

On the morning of the 30th it was sent down into its final position. The momentous experiment proved completely successful. The huge mass of metal descended slowly over the mouth of the tunnel into the black, swift stream at the bottom of the chasm. As its enormous weight crushed the indiarubber pad down into all the inequalities of the floor the outrush of the waters instantly stopped, and the channel ran dry save for the fierce jets of water which spouted out over the top of the plate.

The crevices through which these came were easily plugged, and when this was done it was found that the waters of the lake were rising at the rate of three feet an hour. This proved that, whether the lake had another outlet or not, the damming of the subterranean channels would be quite sufficient to flood the whole valley.

The gate was then raised again, and the waters permitted to flow as before. The triple doors at the entrance to the cavern were already in position when this was done, as the task of placing them had necessarily been much easier than the construction of the water-gate. Nothing but details now remained to be completed, and there was therefore no reason for any further postponement of Alan’s mission.

Alexis had also succeeded in carrying his point, and getting permission to accompany Alan in the Isma. He had had no difficulty in satisfying the Council that the risk would be enormously diminished by sending two air-ships instead of one, for while Alan descended to the earth to convey his message to a hostile city, he would be able to remain in the air, dominating it with his guns, and ready to lay it in ruins if the flag of truce were not respected.

But the two friends had gained even more than this, for in answer to their earnest pleadings, in which it may be suspected they were not altogether unsupported by those as vitally concerned as themselves, a joint family council had decided that, under the unparalleled circumstances of the case, there was no valid reason for refusing consent to their immediate union with the two faithful brides who had waited so long and so patiently for their lords.

Therefore, on the morning of the 31st, it came to pass that they stood upon the spot sanctified by the ashes of their great ancestors, and took each other for man and wife, for life or death, as the hazard of the world’s fate might decide, in the presence of a vast congregation of those who stood with feet already touching the brink of the valley of the shadow of death.

No bridal so strange or solemn had ever been celebrated in the world before. It was human love and hope and genius, serene and confident in the presence of the most awful catastrophe that had ever befallen humanity, defying the fate that was about to overwhelm a world in destruction.

That evening, as the sun was touching the tops of the western mountains, the last preparations for the voyage were completed, the last farewells exchanged, and the Isma and the Avenger, now renamed the Alma by the hands of her name-mother, rose into the air amid salvoes of aerial artillery, and winged their way northward over the Ridge.

As they sped out over the plains of Northern Africa the sun sank, and out of the north-western heavens shone the luminous haze of the Fire-Cloud, which had now grown in visible magnitude until the two fan-like wings which spread out from its central nucleus spanned an arc of twenty degrees in the heavens.

As the two air-ships sped on their northward course towards Alexandria, where Alan had decided to make his first attempt to stay the progress of the world-war, the two pairs of new-wedded lovers watched with anxious eyes from the decks of their flying craft the terrible portent in the skies whose meaning they above all others on earth were so well qualified to read.

There could be no doubt now, even apart from all the elaborate calculations which had been made, that the prediction of the Martian astronomers was far more likely to be fulfilled than contradicted by the event.

Yet, so great was the happiness they found in this strange fulfilment of the faint hopes of years of almost hopeless waiting that, even as they journeyed on through the night with this threatening sign of approaching ruin pouring its angry light out of the skies, their talk was still rather of love and life and hope than of the death and desolation which they knew to be overhanging their race with such remorseless certainty.

They had lived and loved, and their love had found fruition. What more could they have asked of Fate than this, even if they could have prolonged their lives indefinitely by a mere effort of will? As Alan had said to Alma at the moment of their re-betrothal in the palm-grove, they were immortal now, and for them the death of a world was but an accident on the onward progress of an evolution in which such souls as theirs, veritable sparks of the divine fire itself, were the dominating factors.

As the Fire-Cloud paled in the West, and the eastern heavens brightened with the fore-glow of the coming dawn, the captains of the two vessels were roused by the signals from the conning-towers which told them that Alexandria was in sight.

As soon as he got on deck Alan signalled to the Isma to come close alongside. As she did so and the morning greetings were exchanged, Alma appeared on deck, and suggested that Alexis and Isma should come and have breakfast on board the flagship, so that the two captains could discuss their final plans before descending to the city.

The invitation was of course accepted, and an hour later the Alma commenced her descent towards the Sultan’s palace, above which, from a lofty flagstaff, the banner of Islam was floating lazily in the early morning breeze. She flew no other ensign save a broad white flag of truce that streamed out from the signal-mast at her stern.

The whole city seemed asleep, secure in the conquests that had already been won. A single air-ship floated two thousand feet above the palace, and as he approached her Alan, keeping her well under his guns, flew from his mainmast the signal—“We come in peace. Will you respect the flag?”

The Moslem captain saw at a glance that a single shell would annihilate his vessel, and that the Alma was perfectly protected by her consort, circling two thousand feet above him, so he signalled, “Yes, come alongside.” The Alma descended and swung round until she came on a level with the Moslem vessel, then she ran alongside within speaking distance, the doors of the deck-chambers were opened, and Alan, after exchanging salutes, asked her captain whether the Sultan was in his capital.

“Yes,” replied the Moslem. “He is down yonder in his palace awaiting the coming of the Tsarina, for they are to join hands to-day and reign lord and mistress of the world they have conquered.”

“Is the world, then, conquered?” asked Alan, with a smile on his lips and a note of scornful pity in his voice.

“Yes,” said the Moslem. “East and west, north and south, the world is ours, saving only your own little land, and for that, I suppose, you have come to make terms of peace.”

“I have not come to make terms of peace for Aeria, but for the world,” replied Alan gravely. “But of that I must speak with your master. When will he be able to give me an audience?”

“That I cannot say,” was the reply, “or even that he will hear you at all. But, pardon! I did not know that the angels of Paradise accompanied the Aerians on their voyages. Descend in peace, my master will receive you.”

As he was speaking Alma, crowned with her crystal wings, and radiant with a beauty which, to the Moslem’s eyes, seemed something superhuman, had come from the after part of the vessel to Alan’s side. It was the first time that he had ever seen a woman of Aeria; and, with the innate chivalry of his race, he paid his involuntary homage to her as he would have done to an incarnation of one of the poetic dreams of his faith.

Then salutes were exchanged again between the two captains and the Alma sank swiftly downwards until she hovered twenty feet above the terrace on which Alan had first spoken with the Sultan on the night that he captured the Vindaya.

The approach of the Aerian warship had already summoned a party of guards to the roof, and after a brief parley a message was carried to the Sultan from Alan. A few minutes later Khalid stepped out of the doorway leading from the interior of the palace, magnificently attired as though for some great ceremonial.

He looked up and saw Alan standing with Alma by his side on the after-deck of his ship. He saw, too, that the flag of truce was flying from the stern and that the guns were laid alongside instead of being pointed down upon the city. He raised his hand in salute and said—

“I see you come in the guise of peace. If that is so you are welcome.”

“It is peace if your Majesty will have it so,” replied Alan, returning his salute, and at the same time making a sign for the Alma to descend to the roof of the palace. As her keels touched the floor of the terrace, the steps fell from the after doorway, and he came down, leaving Alma standing on deck by the open door.

“Will not your companion honour my palace by touching its roof with her foot?” said Khalid, looking up at Alma as he exchanged greetings with Alan.

“My companion, Sultan, is the wife of the man whom you turned your back upon on this very spot as a liar, a traitor, and a murderer,” said Alan, looking him straight in the eyes. “How, then, could she honour your palace by setting foot on its roof?”

For a moment the Sultan was abashed into silence by the directness of the rebuke, and then his Oriental subtlety and quickness of thought came to his aid, and, bending his head with royal dignity, he said—

“The angels do not mate with such men as that. The Tsarina must have been misled by appearances, perhaps, indeed, carried away by her hereditary hatred of your people. It is impossible that any but a true man could have won the love of such a woman. You tell me that you come as friends and not as enemies, so, for the hour, let there be peace, not war, between us. While you are my guests my city is yours, and all that it contains. I pledge my honour for your safety, so let the Daughter of the Air descend that I may hear from her lips the music of her voice.”

Turning aside, half to hide a smile at the Oriental metaphor of the Sultan’s speech, Alan went to the foot of the steps and held out his hand to Alma. As she alighted on the terrace he led her towards him, saying—

“This is my wife. Yesterday morning she was Alma Tremayne, a daughter in the fifth generation of the first President of the Federation. Her ancestor and yours made terms of peace after the War of the Terror. It is, therefore, more fitting that you should hear from her lips than from mine the message that we bring.”

“My ears are waiting,” said Khalid, bending low over the hand that Alma held out to him as Alan spoke. “It would be a strange message that would not be welcome from such lips.”

From one whom she could have looked upon as an equal such language as this would have jarred sorely upon Alma, accustomed as she was to the frank directness of her own people’s speech. But from Khalid she tolerated it as she would have tolerated the extravagance of a child, and as he raised his head again she looked at him with eyes that dazzled him afresh, intoxicated as he already was with her, to him, strange and almost unearthly beauty, and said in a voice such as he had never heard before—

“Thank you, Sultan, for your welcome, but surely there is little need for me to tell you what message we bring. Last night you saw it written in letters of fire across the heavens. Has not the voice of God spoken bidding you and your people to cease the cruel warfare that you are waging upon the world and to prepare for the end of which that is a sign?”

As she spoke she raised her hand and pointed to where the shape of the Fire-Cloud now hung in the sky like a white mist paling before the light of the rising sun.

“You rejected our first warning, as perhaps was natural, but now that you have seen the confirmation of it shining among the stars, surely you will no longer reject it.”

The last words were spoken in a gentle, pleading tone, which no man could have heard without being moved by them.

“Daughter of the Air,” replied the Sultan, following her hand with his eyes, “I have seen, and in a measure I believe, your message, though my interpretation of it may be other than yours. If the end of the world is at hand, the Commander of the Faithful will know how to meet it as a true believer should. It is not impossible that there may be peace between us yet in the last hours of earthly life, for I would not willingly make war on a people that has daughters such as you.”

“Not for our sake, Sultan, but for the sake of all who have survived this terrible warfare of yours we are come to plead with you for peace,” said Alma. “This is no time for hate and strife and bloodshed. There will be horrors enough upon earth before long without any made by the fury of man. It is in your power to give peace to the world and breathing space to meet its end. Why will you not give it?”

“You forget it is not I alone who can give peace,” replied Khalid. “If that were so”—

Before he could speak another word a salvo of aerial artillery shook the air above the city. All looked up towards the northern sky, whence the sound proceeded, and saw a squadron of twenty silvery-hulled air-ships flying the Moslem and Russian flags, and escorting in two divisions a warship, from whose flagstaff flew the imperial standard of Russia, and whose shining hull of azurine proclaimed her the lost Ithuriel.

Alan grasped the perilous situation in an instant, and was just about to tell Alma to go back on board their own ship when the Sultan, divining his intention, took a step forward and said—

“Do you think that Khalid cannot protect his guests or that his ally will not respect the hospitality of his house? You are safe. If a hair of your head were harmed the Tsarina and I would be enemies and she would come to her death instead of her bridal, for that is what brings her here. There is truce between us for this day at least, and she shall not break it.”

As he ceased speaking the twenty air-ships opened out into a long line and remained suspended five hundred feet above the palace, while the Revenge continued her downward flight and alighted at the farther end of the terrace from where they were standing.

The after door of the deck-chamber opened as she touched the marble pavement, the steps dropped down, and Olga descended, attired as usual in a plain robe of royal purple, over which hung a travelling mantle of pearl-grey cloth as fine and soft as silk and lined with the then almost priceless fur of the silver fox.

Her head was uncovered save for a plain golden fillet, from which rose a pair of slender silver wings so thickly encrusted with diamonds that they seemed entirely fashioned of the flashing gems. The golden fillet shone out brightly yellow against the lustrous black of her thickly-coiled hair, and the diamond wings blazed and scintillated in the sunlight with every movement of her head.

As she descended the steps she was followed by Orloff Lossenski and a guard of honour of twelve of her officers, splendidly dressed, and armed to the teeth, who, as soon as they landed, drew their swords, which were now only used as ornamental insignia of rank, and ranged themselves in two lines, one on either side of her.

Before the Revenge had alighted the Sultan had made a sign to one of the sentries, who blew a long, clear blast on a silver bugle, which was instantly answered by a hundred others from various parts of the city. At the sound the Moslem metropolis seemed to wake from sleep into universal activity.

Thousands of soldiers in brilliant uniforms poured into the empty streets, the Moslem and Russian flags ran up to a thousand flagstaffs, squadron after squadron of aerial cruisers soared up from the earth and saluted with salvoes of artillery, which shook the very firmament and brought Alexis down to within three thousand feet of the palace roof in the belief that Alan and Alma had fallen victims to some treachery, and that the time had come for him to avenge them by laying the city in ruins, as he had promised to do in such an event.

A single glance through his field-glasses showed him the true state of affairs, so he contented himself with keeping his crew at quarters with every gun trained on a Russian or a Moslem air-ship and ready to spread death and ruin far and wide should any harm happen to the Alma or her crew.

While this was taking place the Sultan’s bodyguard had filed out on to the terrace resplendent with gorgeous uniforms and glittering weapons, and between the two long lines that they formed Khalid advanced to meet his bride, leaving Alan and Alma interested and not unanxious spectators of the strange and unexpected scene.

They met half-way down the double line, and as Olga held out the hand over which Khalid bowed low as he raised it to his lips, she said, with a glance of undisguised hate towards Alan and Alma and a mocking smile on her lips—

“Your Majesty’s generosity is unbounded! I see that you have invited to our wedding-feast the only enemies with whom we have yet to measure swords!”

“They have not come as enemies, Tsarina,” replied Khalid, as he raised his head and looked with but half-restrained ardour on the beauty that was so soon to be his. “Nor yet have they come at my invitation. Alan Arnold and his wife”—

“His what!” interrupted Olga, her cheeks burning and her eyes flashing with a sudden blaze of uncontrollable anger.

“His wife, Tsarina,” replied Khalid, somewhat coldly. “The son of Natasha and Richard Arnold has mated with the daughter of Alan Tremayne, and they have come in the fifth generation to warn you, the daughter of the House of Romanoff, and me, the son of the line of Mohammed Reshad, to cease our warfare upon the nations and prepare for the universal end which, they tell us, is at hand.”

Khalid spoke, as Olga thought, half in jest and half in earnest, so she continued in the same mocking tone in which she had first spoken—

“Then if that is so, if all human enmities are soon to be purged by the all-destroying fires, we may as well meet in peace for the moment. Will your Majesty honour me by presenting me to your uninvited guests?”

“Uninvited, but still my guests, Tsarina,” replied Khalid gravely, “and therefore I need not ask you”—

“No, Sultan,” said Olga, interrupting him, “you need ask me nothing. You need not fear that I shall not respect the hospitality of your house, even when extended to them.”

As she spoke she gave him her hand again and he led her between the silent, rigid ranks of his guards to where Alan and Alma were standing.

Since men and women had learned to love and hate there had been no such strange meeting between two women as that which now took place between Alma and Olga. It was the first time that Olga had ever seen a woman of the race to which Alan belonged, and Alma, for the first time confronted with a daughter of the “earth-folk,” saw in Olga Romanoff at once the most beautiful woman outside the confines of Aeria and the incarnation of everything that she had been trained to look upon as evil.

While the Sultan was speaking the words of presentation their eyes met, and Alma thought of that sentence in Alan’s letter to his father, “She is as beautiful as an angel and as merciless as a fiend,” while Olga looked back to the time when she first heard Alma’s name and hated her for the sake of him who now stood beside her, her lover and her husband—the man she had held in bondage for years without winning one voluntary caress from him.

Alma’s first emotion was one of wonder. Hitherto, she had seen nothing beautiful that was not at the same time good, for in Aeria the conceptions of beauty and goodness were inseparable. But here was a woman of almost perfect physical loveliness, after her own type, who was beyond all doubt guilty of the most colossal crime that a human soul had conceived or a human hand had carried out since men first learned to sin.

The world, which ten years before had been a paradise of peace, prosperity, and enlightened progress, was now a wilderness of misery and an inferno of strife, fast lapsing back into barbarism—and all this was her doing.

As this thought came to Alma’s mind, standing out distinct among all the others that were forcing themselves upon her, wonder gave place to unspeakable horror, and as Olga approached, with the light of hate still burning in her eyes and the same mocking smile upon her lips, she instinctively shrank back as though to avoid contact with some unclean thing. As she did so her hand slipped through Alan’s arm and a visible shudder ran through her form.

Marvellous as Olga’s power of self-control and dissimulation was, she failed entirely to restrain the passion which such a reception aroused within her. It was the first time in her life that she had ever stood in the presence of a woman untainted by a spot of sin or shame, and this woman recoiled from her in visible loathing, beautiful and mighty as she was, at the very zenith of her conquering career and on the morning of her promised union with the man who, as she believed, would before many days share the empire of the world with her.

Hardened as she was, the mute rebuke cut her to the quick. The flush on her cheeks died out and left her so pale for the moment that her face looked almost ghastly with its grey lips and black burning eyes. This daughter of a higher race had at a single glance pierced the splendid mask which covered the fearful deformity of her true nature. She thought of the night long ago in the bedroom at St. Petersburg when by the light of the unearthly flame hovering above her poison-still she had seen her image in the mirror.

Then pride and anger came to her rescue. The blood returned to her cheeks and lips, she drew herself up to the full height of her queenly stature, and as the Sultan spoke the words of presentation she slightly inclined her head, and then raising it again said, in low, even tones, whose wonderful music sent a chill to Alma’s heart—

“This is a pleasant surprise, Alan Arnold. I little thought that after our last parting we should meet again, save in battle, much less did I think that you would honour my bridal by bringing your own bride to it. Still, as the Sultan tells me, there is truce for to-day, and, so far as to my enemy, you are welcome.”

“We have not come as guests to your bridal, Tsarina,” said Alan coldly and gravely, “nor have we come to make truce as between mortal enemies. The enmities of men and nations are but as child’s-play now. We have come to proclaim the Truce of God against the hour of His final judgment.”