VICTORY! It flies! I am master of the Powers of the Air at last!"

They were strange words to be uttered, as they were, by a pale, haggard, half-starved looking young fellow in a dingy, comfortless room on the top floor of a South London tenement-house; and yet there was a triumphant ring in his voice, and a clear, bright flush on his thin cheeks that spoke at least for his own absolute belief in their truth.

Let us see how far he was justified in that belief.

To begin at the beginning, Richard Arnold was one of those men whom the world is wont to call dreamers and enthusiasts before they succeed, and heaven-born geniuses and benefactors of humanity afterwards.

He was twenty-six, and for nearly six years past he had devoted himself, soul and body, to a single idea -- to the so far unsolved problem of aerial navigation.

This idea had haunted him ever since he had been able to think logically at all -- first dimly at school, and then more clearly at college, where he had carried everything before him in mathematics and natural science, until it had at last become a ruling passion that crowded everything else out of his life, and made him, commercially speaking, that most useless of social units -- a one-idea'd man, whose idea could not be put into working form.

He was an orphan, with hardly a blood relation in the world. He had started with plenty of friends, mostly made at college, who thought he had a brilliant future before him, and therefore looked upon him as a man whom it might be useful to know.

But as time went on, and no results came, these dropped off, and he got to be looked upon as an amiable lunatic, who was wasting his great talents and what money he had on impracticable fancies, when he might have been earning a handsome income if he had stuck to the beaten track, and gone in for practical work.

The distinctions that he had won at college, and the reputation he had gained as a wonderfully clever chemist and mechanician, had led to several offers of excellent positions in great engineering firms; but to the surprise and disgust of his friends he had declined them all. No one knew why, for he had kept his secret with the almost passionate jealousy of the true enthusiast, and so his refusals were put down to sheer foolishness, and he became numbered with the geniuses who are failures because they are not practical.

When he came of age he had inherited a couple of thousand pounds, which had been left in trust to him by his father. Had it not been for that two thousand pounds he would have been forced to employ his knowledge and his talents conventionally, and would probably have made a fortune. But it was just enough to relieve him from the necessity of earning his living for the time being, and to make it possible for him to devote himself entirely to the realisation of his life-dream -- at any rate until the money was gone.

Of course he yielded to the temptation -- nay, he never gave the other course a moment's thought. Two thousand pounds would last him for years; and no one could have persuaded him that with complete leisure, freedom from all other concerns, and money for the necessary experiments, he would not have succeeded long before his capital was exhausted.

So he put the money into a bank whence he could draw it out as he chose, and withdrew himself from the world to work out the ideal of his life.

Year after year passed, and still success did not come. He found practice very different from theory, and in a hundred details he met with difficulties he had never seen on paper. Meanwhile his money melted away in costly experiments which only raised hopes that ended in bitter disappointment His wonderful machine was a miracle of ingenuity, and was mechanically perfect in every detail save one -- it would do no practical work.

Like every other inventor who had grappled with the problem, he had found himself constantly faced with that fatal ratio of weight to power. No engine that he could devise would do more than lift itself and the machine. Again and again he had made a toy that would fly, as others had done before him, but a machine that would navigate the air as a steamer or an electric vessel navigated the waters, carrying cargo and passengers, was still an impossibility while that terrible problem of weight and power remained unsolved.

In order to eke out his money to the uttermost, he had clothed and lodged himself meanly, and had denied himself everything but the barest necessaries of life.

Thus he had prolonged the struggle for over five years of toil and privation and hope deferred, and now, when his last sovereign had been changed and nearly spent, success -- real, tangible, practical success -- had come to him, and the discovery that was to be to the twentieth century what the steam-engine had been to the nineteenth was accomplished.

He had discovered the true motive power at last.

Two liquefied gases -- which, when united, exploded spontaneously -- were admitted by a clockwork escapement in minute quantities into the cylinders of his engine, and worked the pistons by the expansive force of the gases generated by the explosion. There was no weight but the engine itself and the cylinders containing the liquefied gases. Furnaces, boilers, condensers, accumulators, dynamos -- all the ponderous apparatus of steam and electricity -- were done away with, and he had a power at command greater than either of them. There was no doubt about it. The moment that his trembling fingers set the escapement mechanism in motion, the model that embodied the thought and labour of years rose into the air as gracefully as a bird on the wing, and sailed round and round in obedience to its rudder, straining hard at the string which prevented it from striking the ceiling. It was weighted in strict proportion to the load that the full-sized air-ship would have to carry. To increase this was merely a matter of increasing the power of the engine and the size of the floats and fans.

The room was a large one, for the house had been built for a better fate than letting in tenements, and it ran from back to front with a window at each end. Out of doors there was a strong breeze blowing, and as soon as Arnold was sure that his ship was able to hold its own in still air, he threw both the windows open and let the wind blow straight through the room. Then he drew the air-ship down, straightened the rudder, and set it against the breeze. In almost agonised suspense he watched it rise from the floor, float motionless for a moment, and then slowly forge ahead in the teeth of the wind, gathering speed as it went. It was then that he had uttered that triumphant cry of "Victory!" All the long years of privation and hope deferred vanished in that one supreme moment of innocent and bloodless conquest, and he saw himself master of a kingdom as wide as the world itself.

He let the model fly the length of the room before he stopped the clockwork and cut off the motive power, allowing it to sink gently to the floor. Then came the reaction. He looked steadfastly at his handiwork for several moments in silence, and then he turned and threw himself on to a shabby little bed that stood in one corner of the room and burst into a flood of tears.

Triumph had come, but had it not come too late? He knew the boundless possibilities of his invention -- but they had still to be realised. To do this would cost thousands of pounds, and he had just one half-crown and a few coppers. Even these were not really his own, for he was already a week behind with his rent, and another payment fell due the next day. That would be twelve shillings in all, and if it was not paid he would be turned into the street.

As he raised himself from the bed he looked despairingly round the bare, shabby room. No; there was nothing there that he could pawn or sell. Everything saleable had gone already to keep up the struggle of hope against despair. The bed and wash-stand, the plain deal table, and the one chair that comprised the furniture of the room were not his. A little carpenter's bench, a few worn tools and odds and ends of scientific apparatus, and a dozen well-used books -- these were all that he possessed in the world now, save the clothes on his back, and a plain painted sea-chest in which he was wont to lock up his precious model when he had to go out.

His model! No, he could not sell that. At best it would fetch but the price of an ingenious toy, and without the secret of the two gases it was useless. But was not that worth something? Yes, if he did not starve to death before he could persuade any one that there was money in it. Besides, the chest and its priceless contents would be seized for the rent next day, and then --

"God help me! What am I to do?"

The words broke from him like a cry of physical pain, and ended in a sob, and for all answer there was the silence of the room and the inarticulate murmur of the streets below coming up through the open windows. He was weak with hunger and sick with excitement, for he had lived for days on bread and cheese, and that day he had eaten nothing since the crust that had served him for breakfast. His nerves, too, were shattered by the intense strain of his final trial and triumph, and his head was getting light.

With a desperate effort he recovered himself, and the heroic resolution that had sustained him through his long struggle came to his aid again. He got up and poured some water from the ewer into a cracked cup and drank it. It refreshed him for the moment, and he poured the rest of the water over his head. That steadied his nerves and cleared his brain. He took up the model from the floor, laid it tenderly and lovingly in its usual resting-place in the chest. Then he locked the chest and sat down upon it to think the situation over.

Ten minutes later he rose to his feet and said aloud --

"It's no use. I can't think on an empty stomach. I'll go out and have one more good meal if it's the last I ever have in the world, and then perhaps some ideas will come."

So saying, he took down his hat, buttoned his shabby velveteen coat to conceal his lack of a waistcoat, and went out, locking the door behind him as he went.

Five minutes' walk brought him to the Blackfriars Road, and then he turned towards the river and crossed the bridge just as the motley stream of city workers was crossing it in the opposite direction on their homeward journey.

At Ludgate Circus he went into an eating-house and fared sumptuously on a plate of beef, some bread and butter, and a pint mug of coffee. As he was eating a paper-boy came in and laid an Echo on the table at which he was sitting. He took it up mechanically, and ran his eye carelessly over the columns. He was in no humour to be interested by the tattle of an evening paper, but in a paragraph under the heading of Foreign News a once familiar name caught his eye, and he read the paragraph through. It ran as follows:--

RAILWAY OUTRAGE IN RUSSIA.

When the Berlin-Petersburg express stopped last night at Kovno, the first stop after passing the Russian frontier, a shocking discovery was made in the smoking compartment of the palace car which has been on the train for the last few months. Colonel Dornovitch, of the Imperial Police, who is understood to have been on his return journey from a secret mission to Paris, was found stabbed to the heart and quite dead. In the centre of the forehead were two short straight cuts in the form of a T reaching to the bone. Not long ago Colonel Dornovitch was instrumental in unearthing a formidable Nihilist conspiracy, in connection with which over fifty men and women of various social ranks were exiled for life to Siberia. The whole affair is wrapped in the deepest mystery the only clue in the hands of the police being the fact that the cross cut on the forehead of the victim indicates that the crime is the work not of the Nihilists proper, but of that unknown and mysterious society usually alluded to as the Terrorists, not one of whom has ever been seen save in his crimes. How the assassin managed to enter and leave the car unperceived while the train was going at full speed is an apparently insoluble riddle. Saving the victim and the attendants the only passengers in the car who had not retired to rest were another officer in the Russian service and Lord Alanmere, who was travelling to St. Petersburg to resume, after leave of absence, the duties of the Secretaryship to the British Embassy, to which he was appointed some two years ago.

"Why, that must be the Lord Alanmere who was at Trinity in my time, or rather Viscount Tremayne, as he was then," mused Arnold, as he laid the paper down. "We were very good friends in those days. I wonder if he'd know me now, and lend me a ten-pound note to get me out of the infernal fix I'm in? I believe he would, for he was one of the few really good-hearted men I have so far met with.

"If he were in London I really think I should take courage from my desperation, and put my case before him and ask his help. However, he's not in London, and so it's no use wishing. Well, I feel more of a man for that shillingsworth of food and drink, and I'll go and wind up my dissipation with a pipe and a quiet think on the Embankment."

WHEN Richard Arnold reached the Embankment dusk had deepened into night, so far, at least, as nature was concerned. But in London in the beginning of the twentieth century there was but little night to speak of, save in the sense of a division of time. The date of the paper which contained the account of the tragedy on the Russian railway was September 3rd, 1903, and within the last ten years enormous progress had been made in electric lighting.

The ebb and flow in the Thames had at last been turned to account, and worked huge turbines which perpetually stored up electric power that was used not only for lighting, but for cooking in hotels and private houses, and for driving machinery. At all the great centres of traffic huge electric suns cast their rays far and wide along the streets, supplementing the light of the lesser lamps with which they were lined on each side.

The Embankment from Westminster to Blackfriars was bathed in a flood of soft white light from hundreds of great lamps running along both sides, and from the centre of each bridge a million candle-power sun cast rays upon the water that were continued in one unbroken stream of light from Chelsea to the Tower.

On the north side of the river the scene was one of brilliant and splendid opulence, that contrasted strongly with the halflighted gloom of the murky wilderness of South London, dark and forbidding in its irredeemable ugliness.

From Blackfriars Arnold walked briskly towards Westminster, bitterly contrasting as he went the lavish display of wealth around him with the sordid and seemingly hopeless poverty of his own desperate condition.

He was the maker and possessor of a far greater marvel than anything that helped to make up this splendid scene, and yet the ragged tramps who were remorselessly moved on from one seat to another by the policemen as soon as they had settled themselves down for a rest and a doze, were hardly poorer than he was.

For nearly four hours he paced backwards and forwards, every now and then stopping to lean on the parapet, and once or twice to sit down, until the chill autumn wind pierced his scanty clothing, and compelled him to resume his walk in order to get warm again.

All the time he turned his miserable situation over and over again in his mind without avail. There seemed no way out of it; no way of obtaining the few pounds that would save him from homeless beggary and his splendid invention from being lost to him and the world, certainly for years, and perhaps for ever.

And then, as hour after hour went by, and still no cheering thought came, the misery of the present pressed closer and closer upon him. He dare not go home, for that would be to bring the inevitable disaster of the morrow nearer, and, besides, it was home no longer till the rent was paid. He had two shillings, and he owed at least twelve. He was also the maker of a machine for which the Tsar of Russia had made a standing offer of a million sterling. That million might have been his if he had possessed the money necessary to bring his invention under the notice of the great Autocrat.

That was the position he had turned over and over in his mind until its horrible contradictions maddened him. With a little money, riches and fame were his; without it he was a beggar in sight of starvation.

And yet he doubted whether, even in his present dire extremity, he could, had he had the chance, sell what might be made the most terrific engine of destruction ever thought of to the head and front of a despotism that he looked upon as the worst earthly enemy of mankind.

For the twentieth time he had paused in his weary walk to and fro to lean on the parapet close by Cleopatra's Needle. The Embankment was almost deserted now, save by the tramps and a few isolated wanderers like himself. For several minutes he looked out over the brightly glittering waters below him, wondering listlessly how long it would take him to drown if he dropped over, and whether he would be rescued before he was dead, and brought back to life, and prosecuted the next day for daring to try and leave the world save in the conventional and orthodox fashion.

Then his mind wandered back to the Tsar and his million, and he pictured to himself the awful part that a fleet of airships such as his would play in the general European war that people said could not now be put off for many months longer. As he thought of this the vision grew in distinctness, and he saw them hovering over armies and cities and fortresses, and raining irresistible death and destruction down upon them. The prospect appalled him, and he shuddered as he thought that it was now really within the possibility of realisation; and then his ideas began to translate themselves involuntarily into words which he spoke aloud, completely oblivious for the time being of his surroundings.

"No, I think I would rather destroy it, and then take my secret with me out of the world, than put such an awful power of destruction and slaughter into the hands of the Tsar, or, for the matter of that, any other of the rulers of the earth. Their subjects can butcher each other quite efficiently enough as it is. The next war will be the most frightful carnival of destruction that the world has ever seen; but what would it be like if I were to give one of the nations of Europe the power of raining death and desolation on its enemies from the skies! No, no! Such a power, if used at all, should only be used against and not for the despotisms that afflict the earth with the curse of war!"

"Then why not use it so, my friend, if you possess it, and would see mankind freed from its tyrants?" said a quiet voice at his elbow.

The sound instantly scattered his vision to the winds, and he turned round with a startled exclamation to see who had spoken. As he did so, a whiff of smoke from a very good cigar drifted past his nostrils, and the voice said again in the same quiet, even tones--

"You must forgive me for my bad manners in listening to what you were saying, and also for breaking in upon your reverie. My excuse must be the great interest that your words had for me. Your opinions would appear to be exactly my own, too, and perhaps you will accept that as another excuse for my rudeness."

It was the first really kindly, friendly voice that Richard Arnold had heard for many a long day, and the words were so well chosen and so politely uttered that it was impossible to feel any resentment, so he simply said in answer--

"There was no rudeness, sir; and, besides, why should a gentleman like you apologise for speaking to a"--

"Another gentleman," quickly interrupted his new acquaintance. "Because I transgressed the laws of politeness in doing so, and an apology was due. Your speech tells me that we are socially equals. Intellectually you look my superior. The rest is a difference only of money, and that any smart swindler can bury himself in nowadays if he chooses. But come, if you have no objection to make my better acquaintance, I have a great desire to make yours. If you will pardon my saying so, you are evidently not an ordinary man, or else, something tells me, you would be rich. Have a smoke and let us talk, since we apparently have a subject in common. Which way are you going ?"

"Nowhere -- and therefore anywhere," replied Arnold, with a laugh that had but little merriment in it. "I have reached a point from which all roads are one to me."

"That being the case I propose that you shall take the one that leads to my chambers in Savoy Mansions yonder. We shall find a bit of supper ready, I expect, and then I shall ask you to talk. Come along!"

There was no more mistaking the genuine kindness and sincerity of the invitation than the delicacy with which it was given. To have refused would not only have been churlish, but it would have been for a drowning man to knock aside a kindly hand held out to help him; so Arnold accepted, and the two new strangely met and strangely assorted friends walked away together in the direction of the Savoy.

The suite of rooms occupied by Arnold's new acquaintance was the beau ideal of a wealthy bachelor's abode. Small, compact, cosy, and richly furnished, yet in the best of taste withal, the rooms looked like an indoor paradise to him after the bare squalor of the one room that had been his own home for over two years.

His host took him first into a dainty little bath-room to wash his hands, and by the time he had performed his scanty toilet supper was already on the table in the sitting-room. Nothing melts reserve like a good well-cooked meal washed down by appropriate liquids, and before supper was half over Arnold and his host were chatting together as easily as though they stood on perfectly equal terms and had known each other for years. His new friend seemed purposely to keep the conversation to general subjects until the meal was over and his pattern man-servant had removed the cloth and left them together with the wine and cigars on the table.

As soon as he had closed the door behind him his host motioned Arnold to an easy-chair on one side of the fireplace, threw himself into another on the other side, and said--

"Now, my friend, plant yourself, as they say across the water, help yourself to what there is as the spirit moves you, and talk -- the more about yourself the better. But stop. I forgot that we do not even know each other's name yet. Let me introduce myself first.

"My name is Maurice Colston; I am a bachelor, as you see. For the rest, in practice I am an idler, a dilettante, and a good deal else that is pleasant and utterly useless. In theory, let me tell you, I am a Socialist, or something of the sort, with a lively conviction as to the injustice and absurdity of the social and economic conditions which enable me to have such a good time on earth without having done anything to deserve it beyond having managed to be born the son of my father."

He stopped and looked at his guest through the wreaths of his cigar smoke as much as to say: "And now who are you?"

Arnold took the silent hint, and opened his mouth and his heart at the same time. Quite apart from the good turn he had done him, there was a genial frankness about his unconventional host that chimed in so well with his own nature that he cast all reserve aside, and told plainly and simply the story of his life and its master passion, his dreams and hopes and failures, and his final triumph in the hour when triumph itself was defeat.

His host heard him through without a word, but towards the end of his story his face betrayed an interest, or rather an expectant anxiety, to hear what was coming next that no mere friendly concern of the moment for one less fortunate than himself could adequately account for. At length, when Arnold had completed his story with a brief but graphic description of the last successful trial of his model, he leant forward in his chair, and, fixing his dark, steady eyes on his guest's face, said in a voice from which every trace of his former good-humoured levity had vanished--

"A strange story, and truer, I think, than the one I told you. Now tell me on your honour as a gentleman: Were you really in earnest when I heard you say on the embankment that you would rather smash up your model and take the secret with you into the next world, than sell your discovery to the Tsar for the million that he has offered for such an air-ship as yours?"

"Absolutely in earnest," was the reply. "I have seen enough of the seamy side of this much-boasted civilisation of ours to know that it is the most awful mockery that man ever insulted his Maker with. It is based on fraud, and sustained by force -- force that ruthlessly crushes all who do not bow the knee to Mammon. I am the enemy of a society that does nob permit a man to be honest and live, unless he has money and can defy it. I have just two shillings in the world, and I would rather throw them into the Thames and myself after them than take that million from the Tsar in exchange for an engine of destruction that would make him master of the world."

"Those are brave words," said Colston, with a smile. "Forgive me for saying so, but I wonder whether you would repeat them if I told you that I am a servant of his Majesty the Tsar, and that you shall have that million for your model and your secret the moment that you convince me that what you have told me is true."

Before he had finished speaking Arnold had risen to his feet. He heard him out, and then he said, slowly and steadily--

"I should not take the trouble to repeat them; I should only tell you that I am sorry that I have eaten salt with a man who could take advantage of my poverty to insult me. Good night."

He was moving towards the door when Colston jumped up from his chair, strode round the table, and got in front of him. Then he put his two hands on his shoulders, and, looking straight into his eyes, said in a tone that vibrated with emotion--

"Thank God, I have found an honest man at last! Go and sit down again, my friend, my comrade, as I hope you soon will be. Forgive me for the foolishness that I spoke! I am no servant of the Tsar. He and all like him have no more devoted enemy on earth than I am. Look! I will soon prove it to you."

As he said the last words, Colston let go Arnold's shoulders, flung off his coat and waistcoat, slipped his braces off his shoulders, and pulled his shirt up to his neck. Then he turned his bare back to his guest, and said--

"That is the sign-manual of Russian tyranny -- the mark of the knout!"

Arnold shrank back with a cry of horror at the sight. From waist to neck Colston's back was a mass of hideous scars and wheels, crossing each other and rising up into purple lumps, with livid blue and grey spaces between them. As he stood, there was not an inch of naturally-coloured skin to be seen. It was like the back of a man who had been flayed alive, and then flogged with a cat-o'-nine-tails.

Before Arnold had overcome his horror his host had readjusted his clothing. Then he turned to him and said--

"That was my reward for telling the governor of a petty Russian town that he was a brute-beast for flogging a poor decrepid old Jewess to death. Do you believe me now when I say that I am no servant or friend of the Tsar?"

"Yes, I do," replied Arnold, holding out his hand, "you were right to try me, and I was wrong to be so hasty. It is a failing of mine that has done me plenty of harm before now. I think I know now what you are without your telling me. Give me a piece of paper and you shall have my address, so that you can come to-morrow and see the model -- only I warn you that you will have to pay my rent to keep my landlord's hands off it. And then I must be off, for I see it's past twelve."

"You are not going out again to-night, my friend, while I have a sofa and plenty of rugs at your disposal," said his host. " You will sleep here, and in the morning we will go together and see this marvel of yours. Meanwhile sit down and make yourself at home with another cigar. We have only just begun to know each other -- we two enemies of Society!"

SOON after eight the next morning Colston came into the sitting-room where Arnold had slept on the sofa, and dreamt dreams of war and world-revolts and battles fought in mid-air between aerial navies built on the plan of his own model. When Colston came in he was just awake enough to be wondering whether the events of the previous night were a reality or part of his dreams -- a doubt that was speedily set at rest by his host drawing back the curtains and pulling up the blinds.

The moment his eyes were properly open he saw that he was anywhere but in his own shabby room in Southwark, and the rest was made clear by Colston saying --

"Well, comrade Arnold, Lord High Admiral of the Air, how have you slept? I hope you found the sofa big and soft enough, and that the last cigar has left no evil effects behind it."

"Eh? Oh, good morning! I don't know whether it was the whisky or the cigars, or what it was; but do you know I have been dreaming all sorts of absurd things about battles in the air and dropping explosives on fortresses and turning them into small volcanoes. When you came in just now I hadn't the remotest idea where I was. It's time to get up, I suppose?"

"Yes, it's after eight a good bit. I've had my tub, so the bath-room is at your service. Meanwhile, Burrows will be laying the table for breakfast. When you have finished your tub, come into my dressing-room, and let me rig you out. We are about of a size, and I think I shall be able to meet your most fastidious taste. In fact, I could rig you out as anything -- from a tramp to an officer of the Guards."

"It wouldn't take much change to accomplish the former, I'm afraid. But, really, I couldn't think of trespassing so far on your hospitality as to take your very clothes from you. I'm deep enough in your debt already."

"Don't talk nonsense, Richard Arnold. The tone in which those last words were said shows me that you have not duly laid to heart what I said last night. There is no such thing as private property in the Brotherhood, of which I hope, by this time to-morrow, you will be an initiate.

"What I have here is mine only for the purposes of the Cause, wherefore it is as much yours as mine, for to-day we are going on the Brotherhood's business. Why, then, should you have any scruples about wearing the Brotherhood's clothes? Now clear out and get tubbed, and wash some of those absurd ideas out of your head."

"Well, as you put it that way, I don't mind, only remember that I don't necessarily put on the principles of the Brotherhood with its clothes."

So saying, Arnold got up from the sofa, stretched himself, and went off to make his toilet.

When he sat down to breakfast with his host half an hour later, very few who had seen him on the Embankment the night before would have recognised him as the same man. The tailor after all, does a good deal to make the man, externally at least, and the change of clothes in Arnold's case had transformed him from a superior looking tramp into an aristocratic and decidedly good-looking man, in the prime of his youth, saving only for the thinness and pallor of his face, and a perceptible stoop in the shoulders.

During breakfast they chatted about their plans for the day and then drifted into generalities, chiefly of a political nature.

The better Arnold came to know Maurice Colston the more remarkable his character appeared to him; and it was his growing wonder at the contradictions that it exhibited that made him say towards the end of the meal--

"I must say you're a queer sort of conspirator, Colston. My idea of Nihilists and members of revolutionary societies has always taken the form of silent, stealthy, cautious beings, with a lively distrust and hatred of the whole human race outside their own circles. And yet here are you, an active member of the most terrible secret society in existence, pledged to the destruction of nearly every institution on earth, and carrying your life in your hand, opening your heart like a schoolboy to a man you have literally not known for twenty-four hours.

"Suppose you had made a mistake in me. What would there be to prevent me telling the police who you are, and having you locked up with a view to extradition to Russia?"

"In the first place," replied Colston quietly, "you would not do so, because I am not mistaken in you, and because, in your heart, whether you fully know it or not, you believe as I do about the destruction that is about to fall upon Society.

"In the second place, if you did betray my confidence, I should be able to bring such an overwhelming array of the most respectable evidence to show that I was nothing like what I really am, that you would be laughed at for a madman; and, in the third place, there would be an inquest on you within twenty-four hours after you had told your story. Do you remember the death of Inspector Ainsworth, of the Criminal Investigation Department, about six months ago?"

"Yes, of course I do. Hermit and all as I was, I could hardly help hearing about that, considering what a noise it made. But I thought that was cleared up. Didn't one of that gang of garotters that was broken up in South London a couple of months later confess to strangling him in the statement that he made before he was executed?"

"Yes, and his widow is now getting ten shillings a week for life on account of that confession. Birkett no more killed Ainsworth than you did; but he had killed two or three others, and so the confession didn't do him very much harm.

"No; Ainsworth met his death in quite another way. He accepted from the Russian secret police bureau in London a bribe of £250 down and the promise of another £250 if he succeeded in manufacturing enough evidence against a member of our Outer Circle to get him extradited to Russia on a trumped-up charge of murder.

"The Inner Circle learnt of this from one of our spies in the Russian London police, and ---, well, Ainsworth was found dead with the mark of the Terror upon his forehead before he had time to put his treachery into action. He was executed by two of the Brotherhood, who are members of the Metropolitan police force, and who were afterwards complimented by the magistrate for the intelligent efforts they had made in bringing the murderers to justice."

Colston told the dark story in the most careless of tones between the puffs of his after-breakfast cigarette. Arnold stifled his horror as well as he was able, but he could not help saying, when his host had done--

"This Brotherhood of yours is well named the Terror; but was not that rather a murder than an execution?"

"By no means," replied Colston, a trifle coldly. "Society hangs or beheads a man who kills another. Ainsworth knew as well as we did that if the man he tried to betray by false evidence had once set foot in Russia, the torments of a hundred deaths would have been his before he had been allowed to die.

"He betrayed his office and his faith to his English masters in order to commit this vile crime, and so he was killed as a murderous and treacherous reptile that was not fit to live. We of the Terror are not lawyers, and so we make no distinctions between deliberate plotting for money to kill and the act of killing itself. Our law is closer akin to justice than the hairsplitting fraud that is tolerated by Society."

Either from emotional or logical reasons Arnold made no reply to this reasoning, and, seeing he remained silent, Colston resumed his ordinary nonchalant, good-humoured tone, and went on --

"But come, that will be horrors enough for to-day. We have other business in hand, and we may as well get to it at once. About this wonderful invention of yours. Of course I believe all you have told me about it, but you must remember that I am only an agent, and that I am inexorably bound by certain rules, in accordance with which I must act.

"Now, to be perfectly plain with you, and in order that we may thoroughly understand each other before either of us commits himself to anything, I must tell you that I want to see this model flying ship of yours in order to be able to report on it to-night to the Executive of the Inner Circle, to whom I shall also want to introduce you. If you will not allow me to do that say so at once, and, for the present at least, our negotiations must come to a sudden stop."

"Go on," said Arnold quietly; "so far I consent. For the rest I would rather hear you to the end."

"Very well. Then if the Executive approve of the invention, you will be asked to join the Inner Circle at once, and to devote yourself body and soul to the Society and the accomplishment of the objects that will be explained to you. If you refuse there will be an end of the matter, and you will simply be asked to give your word of honour to reveal nothing that you have seen or heard, and then allowed to depart in peace.

"If, on the other hand, you consent, in consideration of the immense importance of your secret -- which there is no need to disguise from you -- to the Brotherhood, the usual condition of passing through the Outer Circle will be dispensed with, and you will be trusted as absolutely as we shall expect you to trust us.

"Whatever funds you then require to manufacture an airship on the plan of your model will be placed at your disposal, and a suitable place will be selected for the works that you will have to build. When the ship is ready to take the air you will, of course, be appointed to the command of her, and you will pick your crew from among the workmen who will act under your orders in the building of the vessel.

"They will all be members of the Outer Circle, who will not understand your orders, but simply obey them blindly, even to the death. One member of the Inner Circle will act as your second in command, and he will be as perfectly trusted as you will be, so that in unforeseen emergencies you will be able to consult with him with perfect confidence. Now I think I have told you all. What do you say?"

Arnold was silent for a few minutes, too busy for speech with the rush of thoughts that had crowded through his brain as Colston was speaking. Then he looked up at his host and said--

"May I make conditions?"

"You may state them," replied he, with a smile, "but, of course, I don't undertake to accept them without consultation with my -- I mean with the Executive."

"Of course not," said Arnold. " Well, the conditions that I should feel myself obliged to make with your Executive would be, briefly speaking, these: I would not reveal to any one the composition of the gases from which I derive my motive force. I should manufacture them myself in given quantities, and keep them always under my own charge.

"At the first attempt to break faith with me in this respect I would blow the air-ship and all her crew, including myself, into such fragments as it would be difficult to find one of them. I have and wish for no life apart from my invention, and I would not survive it."

"Good!" interrupted Colston. "There spoke the true enthusiast. Go on."

"Secondly, I would use the machine only in open warfare-- when the Brotherhood is fighting openly for the attainment of a definite end. Once the appeal to force has been made I will employ a force such as no nation on earth can use without me, and I will use it as unsparingly as the armies and fleets engaged will employ their own engines of destruction on one another. But I will be no party to the destruction of defenceless towns and people who are not in arms against us. If I am ordered to do that I tell you candidly that I will not do it. I will blow the airship itself up first."

"The conditions are somewhat stringent, although the sentiments are excellent," replied Colston; "still, of myself I can neither accept nor reject them. That will be for the Executive to do. For my own part I think that you will be able to arrive at a basis of agreement on them. And now I think we have said all we can say for the present, and so if you are ready we'll be off and satisfy my longing to see the invention that is to make us the arbiters of war -- when war comes, which I fancy will not be long now."

Something in the tone in which these last words were spoken struck Arnold with a kind of cold chill, and he shivered slightly as he said in answer to Colston--

"I am ready when you are, and no less anxious than you to set eyes on my model. I hope to goodness it is all safe! Do you know, when I am away from it I feel just like a woman away from her first baby."

A few minutes later two of the most dangerous enemies of Society alive were walking quietly along the Embankment towards Blackfriars, smoking their cigars and chatting as conventionally as though there were no such things on earth as tyranny and oppression, and their necessarily ever-present enemies conspiracy and brooding revolution.

TWENTY minutes' walk took Arnold and Colston to the door of the tenement-house in which the former had lived since his fast-dwindling store of money had convinced him of the necessity of bringing his expenses down to the lowest possible limit if he wished to keep up the struggle with fate very much longer.

As they mounted the dirty, evil-smelling staircase, Colston said--

"Phew! Verily you are a hero of science if you have brought yourself to live in a hole like this for a couple of years rather than give up your dream, and grow fat on the loaves and fishes of conventionality."

"This is a palace compared with some of the rookeries about here," replied Arnold, with a laugh. "The march of progress seems to have left this half of London behind as hopeless. Ten years ago there were a good many thousands of highly respectable mediocrities living on this side of the river, but now I am told that the glory has departed from the very best of its localities, and given them up to various degrees of squalor. Vice, poverty, and misery seem to gravitate naturally southward in London. I don't know why, but they do. Well, here is the door of my humble den."

As he spoke he put the key in the lock, and opened the door, bidding his companion enter as he did so. Arnold's anxiety was soon relieved by finding the precious model untouched in its resting-place, and it was at once brought out. Colston was delighted beyond his powers of expression with the marvellous ingenuity with which the miracle of mechanical skill was contrived and put together; and when Arnold, after showing and explaining to him all the various parts of the mechanism and the external structure, at length set the engine working, and the air-ship rose gracefully from the floor and began to sail round the room in the wide circle to which it was confined by its mooring-line, he stared at it for several minutes in wondering silence, following it round and round with his eyes, and then he said in a voice from which he vainly strove to banish the signs of the emotion that possessed him--

"It is the last miracle of science! With a few such ships as that one could conquer the world in a month!"

"Yes, that would not be a very difficult task, seeing that neither an army nor a fleet could exist for twelve hours with two or three of them hovering above it," replied Arnold.

The trial over, Arnold set to work and took the model partly to pieces for packing up; and while he was putting it away in the old sea-chest, Colston counted out ten sovereigns and laid them on the table. Hearing the clink of the gold, Arnold looked up and said--

"What is that for? A sovereign will be quite enough to get me out of my present scrape, and then if we come to any terms to-night it will be time enough to talk about payment."

"The Brotherhood does not do business in that way," was the reply. "At present your only connection with it is a commercial one, and ten pounds is a very moderate fee for the privilege of inspecting such an invention as this. Anyhow, that is what I am ordered to hand over to you in payment for your trouble now and to-night, so you must accept it as it is given -- as a matter of business."

"Very well," said Arnold, closing and locking the chest as he spoke, "if you think it worth ten pounds, the money will not come amiss to me. Now, if you will remain and guard the household gods for a minute, I will go and pay my rent and get a cab."

Half an hour later his few but priceless possessions were loaded on a four-wheeler and Arnold had bidden farewell for ever to the dingy room in which he had passed so many hours of toil and dreaming, suffering and disappointment. Before lunch time they were safely bestowed in a couple of rooms which Colston had engaged for him in the same building in which his own rooms were.

In the afternoon, among other purchases, a more convenient case was bought for the model, and in this it was packed with the plans and papers which explained its construction, ready for the evening journey. The two friends dined together at six in Colston's rooms, and at seven sharp his servant announced that the cab was at the door. Within ten minutes they were bowling along the Embankment towards Westminster Bridge in a luxuriously appointed hansom of the newest type, with the precious case lying across their knees.

"This is a comfortable cab," said Arnold, when they had gone a hundred yards or so. "By the way, how does the man know where to go? I didn't hear you give him any directions."

"None were necessary," was the reply. "This cab, like a good many others in London, belongs to the Brotherhood, and the man who is driving is one of the Outer Circle. Our Jehus are the most useful spies that we have. Many is the secret of the enemy that we have learnt from, and many is the secret police agent who has been driven to his rendezvous by a Terrorist who has heard every word that has been spoken on the journey."

"How on earth is that managed?"

"Every one of the cabs is fitted with a telephonic arrangement communicating with the roof. The driver has only to button the wire of the transmitter up inside his coat so that the transmitter itself lies near to his ear, and he can hear even a whisper inside the cab.

"The man who is driving us, for instance, has a sort of retainer from the Russian Embassy to be on hand at certain hours on certain nights in the week. Our cabs are all better horsed, better appointed, and better driven than any others in London, and, consequently, they are favourites, especially among the young attaches, and are nearly always employed by them on their secret missions or love affairs, which, by the way, are very often the same thing. Our own Jehu has a job on to-night, from which we expect some results that will mystify the enemy not a little. We got our first suspicions of Ainsworth from a few incautious words that he spoke in one of our cabs."

"It's a splendid system, I should think, for discovering the movements of your enemies," said Arnold, not without an uncomfortable reflection on the fact that he was himself now completely in the power of this terrible organisation, which had keen eyes and ready hands in every capital of the civilised world. "But how do you guard against treachery? It is well known that all the Governments of Europe are spending money like water to unearth this mystery of the Terror. Surely all your men cannot be incorruptible."

"Practically they are so. The very mystery which enshrouds all our actions makes them so. We have had a few traitors, of course; but as none of them has ever survived his treachery by twenty-four hours, a bribe has lost its attraction for the rest."

In such conversation as this the time was passed, while the cab crossed the river and made its way rapidly and easily along Kennington Road and Clapham Road to Clapham Common. At length it turned into the drive of one of those solid abodes of pretentious respectability which front the Common, and pulled up before a big stucco portico.

"Here we are!" exclaimed Colston, as the doors of the cab automatically opened. He got out first, and Arnold handed the case to him, and then followed him.

Without a word the driver turned his horse into the road again and drove off towards town, and as they ascended the steps the front door opened, and they went in, Colston saying as they did so--

"Is Mr. Smith at home?"

"Yes, sir; you are expected, I believe. Will you step into the drawing-room?" replied the clean-shaven and immaculately respectable man-servant, in evening dress, who had opened the door for them.

They were shown into a handsomely furnished room lit with electric light. As soon as the footman had closed the door behind him, Colston said--

"Well, now, here you are in the conspirators' den, in the very headquarters of those Terrorists for whom Europe is being ransacked constantly without the slightest success. I have often wondered what the rigid respectability of Clapham Common would think if it knew the true character of this harmless-looking house. I hardly think an earthquake in Clapham Road would produce much more sensation that such a discovery would.

"And now," he continued, his tone becoming suddenly much more serious "in a few minutes you will be in the presence of the Inner Circle of the Terrorists, that is to say, of those who practically hold the fate of Europe in their hands. You know pretty clearly what they want with you. If you have thought better of the business that we have discussed you are still at perfect liberty to retire from it, on giving your word of honour not to disclose anything that I have said to you."

"I have not the slightest intention of doing anything of the sort," replied Arnold. "You know the conditions on which I came here. I shall put them before your Council, and if they are accepted your Brotherhood will, within their limits, have no more faithful adherent than I. If not, the business will simply come to an end as far as I am concerned, and your secret will be as safe with me as though I had taken the oath of membership."

"Well said!" replied Colston, "and just what I expected you to say. Now listen to me for a minute. Whatever you may see or hear for the next few minutes say nothing till you are asked to speak. I will say all that is necessary at first. Ask no questions, but trust to anything that may seem strange being explained in due course -- as it will be. A single indiscretion on your part might raise suspicions which would be as dangerous as they would be unfounded. When you are asked to speak do so without the slightest fear, and speak your mind as openly as you have done to me."

"You need have no fear for me," replied Arnold. "I think I am sensible enough to be prudent, and I am quite sure that I am desperate enough to be fearless. Little worse can happen to me than the fate that I was contemplating last night."

As he ceased speaking there was a knock at the door. It opened and the footman reappeared, saying in the most commonplace fashion--

"Mr. Smith will be happy to see you now, gentlemen. Will you kindly walk this way?"

They followed him out into the hall, and then, somewhat to Arnold's surprise, down the stairs at the back, which apparently led to the basement of the house.

The footman preceded them to the basement floor and halted before a door in a little passage that looked like the entrance to a coal cellar. On this he knocked in peculiar fashion with the knuckles of one hand, while with the other he pressed the button of an electric bell concealed under the paper on the wall. The bell sounded faintly as though some distance off, and as it rang the footman said abruptly to Colston--

"Das Wort ist Freiheit."

Arnold knew German enough to know that this meant "The word is 'Freedom'", but why it should have been spoken in a foreign language mystified him not a little.

While he was thinking about this the door opened, as if by a released spring, and he saw before him a long, narrow passage, lit by four electric arcs, and closed at the other end by a door, guarded by a sentry armed with a magazine rifle.

He followed Colston down the passage, and when within a dozen feet of the sentry, he brought his rifle to the "ready," and the following strange dialogue ensued between him and Colston--

"Quien va?"

"Zwei Freunde der Bruderschaft."

"Por la libertad?"

"Für Freiheit über alles!"

"Pass, friends."

The rifle grounded as the words were spoken, and the sentry stepped back to the wall of the passage.

At the same moment another bell rang beyond the door, and then the door itself opened as the other had done. They passed through, and it closed instantly behind them, leaving them in total darkness.

Colston caught Arnold by the arm, and drew him towards him, saying as he did so--

"What do you think of our system of passwords?"

"Pretty hard to get through unless one knew them, I should think. Why the different languages?"

"To make assurance doubly sure every member of the Inner Circle must be conversant with four European languages. On these the changes are rung, and even I did not know what the two languages were to be to-night before I entered the house, and if I had asked for 'Mr. Brown' instead of 'Mr. Smith,' we should never have got beyond the drawing-room.

"When the footman told me in German that the word was 'Freedom,' I knew that I should have to answer the challenge of the sentry in German. I did not know that he would challenge in Spanish, and if I had not understood him, or had replied in any other language but German, he would have shot us both down without saying another word, and no one would ever have known what had become of us. You will be exempt from this condition, because you will always come with me. I am, in fact, responsible for you."

"H'm, there doesn't seem much chance of any one getting through on false pretences," replied Arnold, with an irrepressible shudder: "Has any one ever tried?"

"Yes, once. The two gentlemen whose disappearance made the famous 'Clapham Mystery' of about twelve months ago. They were two of the smartest detectives in the French service and the only two men who ever guessed the true nature of this house. They are buried under the floor on which you are standing at this moment."

The words were spoken with a cruel inflexible coldness, which struck Arnold like a blast of frozen air. He shivered, and was about to reply when Colston caught him by the arm again, and said hurriedly--

"H'st! We are going in. Remember what I said, and don't speak again till some one asks you to do so."

As he spoke a door opened in the wall of the dark chamber in which they had been standing for the last few minutes, and a flood of soft light flowed in upon their dazzled eyes. At the same moment a man's voice said from the room beyond in Russian--

"Who stands there?"

"Maurice Colston and the Master of the Air," replied Colston in the same language.

"You are welcome," was the reply, and then Colston, taking Arnold by the arm, led him into the room.

AS soon as Arnold's eyes got accustomed to the light, he saw that he was in a large, lofty room with panelled walls adorned with a number of fine paintings. As he looked at these his gaze was fascinated by them, even more than by the strange company which was assembled round the long table that occupied the middle of the room.

Though they were all manifestly the products of the highest form of art, their subjects were dreary and repulsive beyond description. There was a horrible realism about them which reminded him irresistibly of the awful collection of pictorial horrors in the Musée Wiertz, in Brussels -- those works of the brilliant but unhappy genius who was driven into insanity by the sheer exuberance of his own morbid imagination.

Here was a long line of men and women in chains staggering across a wilderness of snow that melted away into the horizon without a break. Beside them rode Cossacks armed with long whips that they used on men and women alike when their fainting limbs gave way beneath them, and they were like to fall by the wayside to seek the welcome rest that only death could give them.

There was a picture of a woman naked to the waist, and tied up to a triangle in a prison yard, being flogged by a soldier with willow wands, while a group of officers stood by, apparently greatly interested in the performance. Another painting showed a poor wretch being knouted to death in the market-place of a Russian town, and yet another showed a young and beautiful woman in a prison cell with her face distorted by the horrible leer of madness, and her little white hands clawing nervously at her long dishevelled hair.

Arnold stood for several minutes fascinated by the hideous realism of the pictures, and burning with rage and shame at the thought that they were all too terribly true to life, when he was startled out of his reverie by the same voice that had called them from the dark room saying to him in English--

"Well, Richard Arnold, what do you think of our little picture gallery? The paintings are good in themselves, but it may make them more interesting to you if you know that they are all faithful reproductions of scenes that have really taken place within the limits of the so-called civilised and Christian world. There are some here in this room now who have suffered the torments depicted on those canvases, and who could tell of worse horrors than even they portray. We should like to know what you think of our paintings?"

Arnold glanced towards the table in search of Colston, but he had vanished. Around the long table sat fourteen masked and shrouded forms that were absolutely indistinguishable one from the other. He could not even tell whether they were men or women, so closely were their forms and faces concealed. Seeing that he was left to his own discretion, he laid the case containing the model, which he had so far kept under his arm, down on the floor, and, facing the strange assembly, said as steadily as he could--

"My own reading tells me that they are only too true to the dreadful reality. I think that the civilised and Christian Society which permits such crimes to be committed against humanity, when it has the power to stop them by force of arms, is neither truly civilised nor truly Christian."

"And would you stop them if you could?"

"Yes, if it cost the lives of millions to do it! They would be better spent than the thirty million lives that were lost last century over a few bits of territory."

"That is true, and augurs well for our future agreement. Be kind enough to come to the table and take a seat."

The masked man who spoke was sitting in the chair at the foot of the table, and as he said this one of those sitting at the side got up and motioned to Arnold to take his place. As soon as he had done so the speaker continued--

"We are glad to see that your sentiments are so far in accord with our own, for that fact will make our negotiations all the easier.

"As you are aware, you are now in the Inner Circle of the Terrorists. Yonder empty chair at the head of the table is that of our Chief, who, though not with us in person, is ever present as a guiding influence in our councils. We act as he directs, and it was from him that we received news of you and your marvellous invention. It is also by his direction that you have been invited here to-night with an object that you are already aware of.

"I see from your face that you are about to ask how this can be, seeing that you have never confided your secret to any one until last night. It will be useless to ask me, for I myself do not know. We who sit here simply execute the Master's will. We ask no questions, and therefore we can answer none concerning him."

"I have none to ask," said Arnold, seeing that the speaker paused as though expecting him to say something. "I came at the invitation of one of your Brotherhood to lay certain terms before you, for you to accept or reject as seems good to you. How you got to know of me and my invention is, after all, a matter of indifference to me. With your perfect system of espionage you might well find out more secret things than that."

"Quite so," was the reply. "And the question that we have to settle with you is how far you will consent to assist the work of the Brotherhood with this invention of yours, and on what conditions you will do so."

"I must first know as exactly as possible what the work of the Brotherhood is."

"Under the circumstances there is no objection to your knowing that. In the first place, that which is known to the outside world as the Terror is an international secret society underlying and directing the operations of the various bodies known as Nihilists, Anarchists, Socialists -- in fact, all those organisations which have for their object the reform or destruction, by peaceful or violent means, of Society as it is at present constituted.

"Its influence reaches beyond these into the various trade unions and political clubs, the moving spirits of which are all members of our Outer Circle. On the other side of Society we have agents and adherents in all the Courts of Europe, all the diplomatic bodies, and all the parliamentary assemblies throughout the world.

"We believe that Society as at present constituted is hopeless for any good thing. All kinds of nameless brutalities are practised without reproof in the names of law and order, and commercial economics. On one side human life is a splendid fabric of cloth of gold embroidered with priceless gems, and on the other it is a mass of filthy, festering rags, swarming with vermin.

"We think that such a Society -- a Society which permits considerably more than the half of humanity to be sunk in poverty and misery while a very small portion of it fools away its life in perfectly ridiculous luxury -- does not deserve to exist, and ought to be destroyed.

"We also know that sooner or later it will destroy itself, as every similar Society has done before it. For nearly forty years there has now been almost perfect peace in Europe. At the same time, over twenty millions of men are standing ready to take the field in a week.

"War -- universal war that will shake the world to its foundations -- is only a matter of a little more delay and a few diplomatic hitches. Russia and England are within rifleshot of each other in Afghanistan, and France and Germany are flinging defiances at each other across the Rhine.

"Some one must soon fire the shot that will set the world in a blaze, and meanwhile the toilers of the earth are weary of these dreadful military and naval burdens, and would care very little if the inevitable happened to-morrow.

"It is in the power of the Terrorists to delay or precipitate that war to a certain extent. Hitherto all our efforts have been devoted to the preservation of peace, and many of the so-called outrages which have taken place in different parts of Europe, and especially in Russia, during the last few years, have been accomplished simply for the purpose of forcing the attention of the administrations to internal affairs for the time, and so putting off what would have led to a declaration of war.

"This policy has not been dictated by any hope of avoiding war altogether, for that would have been sheer insanity. We have simply delayed war as long as possible, because we have not felt that we have been strong enough to turn the tide of battle at the right moment in favour of the oppressed ones of the earth and against the oppressors.

"But this invention of yours puts a completely different aspect on the European situation. Armed with such a tremendous engine of destruction as a navigable air-ship must necessarily be, when used in conjunction with the explosives already at our disposal, we could make war impossible to our enemies by bringing into the field a force with which no army or fleet could contend without the certainty of destruction. By these means we should ultimately compel peace and enforce a general disarmament on land and sea.

"The vast majority of those who make the wealth of the world are sick of seeing that wealth wasted in the destruction of human life, and the ruin of peaceful industries. As soon, therefore, as we are in a position to dictate terms under such tremendous penalties, all the innumerable organisations with which we are in touch all over the world will rise in arms and enforce them at all costs.

"Of course, it goes without saying that the powers that are now enthroned in the high places of the world will fight bitterly and desperately to retain the rule that they have held for so long, but in the end we shall be victorious, and then on the ruins of this civilisation a new and a better shall arise.

"That is a rough, brief outline of the policy of the Brotherhood, which we are going to ask you to-night to join. Of course, in the eyes of the world we are only a set of fiends, whose sole object is the destruction of Society, and the inauguration of a state of universal anarchy. That, however, has no concern for us. What is called popular opinion is merely manufactured by the Press according to order, and does not count in serious concerns. What I have described to you are the true objects of the Brotherhood; and now it remains for you to say, yes or no, whether you will devote yourself and your invention to carrying them out or not."

For two or three minutes after the masked spokesman of the Inner Circle had ceased speaking, there was absolute silence in the room. The calmly spoken words which deliberately sketched out the ruin of a civilisation and the establishment of a new order of things made a deep impression on Arnold's mind. He saw clearly that he was standing at the parting of the ways, and facing the most tremendous crisis that could occur in the life of a human being.

It was only natural that he should look back, as he did, to the life from which a single step would now part him for ever, without the possibility of going back. He knew that if he once put his hands to the plough, and looked back, death, swift and inevitable, would be the penalty of his wavering. This, however, he had already weighed and decided.

Most of what he had heard had found an echo in his own convictions. Moreover, the life that he had left had no charms for him, while to be one of the chief factors in a world-revolution was a destiny worthy both of himself and his invention. So the fatal resolution was taken, and he spoke the words that bound him for ever to the Brotherhood.

"As I have already told Mr. Colston," he began by saying "I will join and faithfully serve the Brotherhood if the conditions that I feel compelled to make are granted"--

"We know them already," interrupted the spokesman, "and they are freely granted. Indeed, you can hardly fail to see that we are trusting you to a far greater extent than it is possible for us to make you trust us, unless you choose to do so. The air-ship once built and afloat under your command, the game of war would to a great extent be in your own hands. True, you would not survive treachery very long; but, on the other hand, if it became necessary to kill you, the air-ship would be useless, that is, if you took your secret of the motive power with you into the next world."

"As I undoubtedly should," added Arnold quietly.

"We have no doubt that you would," was the equally quiet rejoinder. "And now I will read to you the oath of membership that you will be required to sign. Even when you have heard it, if you feel any hesitation in subscribing to it, there will still be time to withdraw, for we tolerate no unwilling or half-hearted recruits."

Arnold bowed his acquiescence, and the spokesman took a piece of paper from the table and read aloud--

"I, Richard Arnold, sign this paper in the full knowledge that in doing so I devote myself absolutely for the rest of my life to the service of the Brotherhood of Freedom, known to the world as the Terrorists. As long as I live its ends shall be my ends, and no human considerations shall weigh with me where those ends are concerned. I will take life without mercy, and yield my own without hesitation at its bidding. I will break all other laws to obey those which it obeys, and if I disobey these I shall expect death as the just penalty of my perjury."

As he finished reading the oath, he handed the paper to Arnold, saying as he did so--

"There are no theatrical formalities to be gone through. Simply sign the paper and give it back to me, or else tear it up and go in peace."

Arnold read it through slowly, and then glanced round the table. He saw the eyes of the silent figures sitting about him shining at him through the holes in their masks. He laid the paper down on the table in front of him, dipped a pen in an inkstand that stood near, and signed the oath in a firm, unfaltering hand. Then -- committed for ever, for good or evil, to the new life that he had adopted -- he gave the paper back again.

The President took it and read it, and then passed it to the mask on his right hand. It went from one to the other round the table, each one reading it before passing it on, until it got back to the President. When it reached him he rose from his seat, and, going to the fireplace, dropped it into the flames, and watched it until it was consumed to ashes. Then, crossing the room to where Arnold was sitting, he removed his mask with one hand, and held the other out to him in greeting, saying as he did so--

"Welcome to the Brotherhood! Thrice welcome! for your coming has brought the day of redemption nearer!"

AS Arnold returned the greeting of the President, all the other members of the Circle rose from their seats and took off their masks and the black shapeless cloaks which had so far completely covered them from head to foot.

Then, one after the other, they came forward and were formally introduced to him by the President. Nine of the fourteen were men, and five were women of ages varying from middle age almost to girlhood. The men were apparently all between twenty-five and thirty-five, and included some half-dozen nationalities among them.

All, both men and women, evidently belonged to the educated, or rather to the cultured class. Their speech, which seemed to change with perfect ease from one language to another in the course of their somewhat polyglot converse, was the easy flowing speech of men and women accustomed to the best society, not only in the social but the intellectual sense of the word.

All were keen, alert, and swift of thought, and on the face of each one there was the dignifying expression of a deep and settled purpose which at once differentiated them in Arnold's eyes from the ordinary idle or merely money-making citizens of the world.

As each one came and shook hands with the new member of the Brotherhood, he or she had some pleasant word of welcome and greeting for him; and so well were the words chosen, and so manifestly sincerely were they spoken, that by the time he had shaken hands all round Arnold felt as much at home among them as though he were in the midst of a circle of old friends.

Among the women there were two who had attracted his attention and roused his interest far more than any of the other members of the Circle. One of these was a tall and beautifully-shaped woman, whose face and figure were those of a woman in the early twenties, but whose long, thick hair was as white as though the snows of seventy winters had drifted over it. As he returned her warm, firm hand-clasp, and looked upon her dark, resolute, and yet perfectly womanly features, the young engineer gave a slight start of recognition. She noticed this at once and said, with a smile and a quick flash from her splendid grey eyes--

"Ah! I see you recognise me. No, I am not ashamed of my portrait. I am proud of the wounds that I have received in the war with tyranny, so you need not fear to confess your recognition.

It was true that Arnold had recognised her. She was the original of the central figure of the painting which depicted the woman being flogged by the Russian soldiers.

Arnold flushed hotly at the words with the sudden passionate anger that they roused within him, and replied in a low, steady voice--

"Those who would sanction such a crime as that are not fit to live. I will not leave one stone of that prison standing upon another. It is a blot on the face of the earth, and I will wipe it out utterly!"

"There are thousands of blots as black as that on earth, and I think you will find nobler game than an obscure Russian provincial prison. Russia has cities and palaces and fortresses that will make far grander ruins than that -- ruins that will be worthy monuments of fallen despotism," replied the girl, who had been introduced by the President as Radna Michaelis. "But here is some one else waiting to make your acquaintance. This is Natasha. She has no other name among us, but you will soon learn why she needs none."

Natasha was the other woman who had so keenly roused Arnold's interest. Woman, however, she hardly was, for she was seemingly still in her teens, and certainly could not have been more than twenty.

He had mixed but little with women, and during the past few years not at all, and therefore the marvellous beauty of the girl who came forward as Radna spoke seemed almost unearthly to him, and confused his senses for the moment as some potent drug might have done. He took her outstretched hand in awkward silence, and for an instant so far forgot himself as to gaze blankly at her in speechless admiration.

She could not help noticing it, for she was a woman, and for the same reason she saw that it was so absolutely honest and involuntary that it was impossible for any woman to take offence at it. A quick bright flush swept up her lovely face as his hand closed upon hers, her darkly-fringed lids fell for an instant over the most wonderful pair of sapphire-blue eyes that Arnold had ever even dreamed of, and when she raised them again the flush had gone, and she said in a sweet, frank voice--

"I am the daughter of Natas, and he has desired me to bid you welcome in his name, and I hope you will let me do so in my own as well. We are all dying to see this wonderful invention of yours. I suppose you are going to satisfy our feminine curiosity, are you not?"

The daughter of Natas! This lovely girl, in the first sweet flush of her pure and innocent womanhood, the daughter of the unknown and mysterious being whose ill-omened name caused a shudder if it was only whispered in the homes of the rich and powerful, the name with which the death-sentences of the Terrorists were invariably signed, and which had come to be an infallible guarantee that they would be carried out to the letter.

No death-warrants of the most powerful sovereigns of Europe were more certain harbingers of inevitable doom than were those which bore this dreaded name. Whether he were high or low, the man who received one of them made ready for his end. He knew not where or when the fatal blow would be struck. He only knew that the invisible hand of the Terror would strike him as surely in the uttermost ends of the earth as it would in the palace or the fortress. Never once had it missed its aim, and never once had the slightest clue been obtained to the identity of the hand that held the knife or pistol.

Some such thoughts as these flashed one after another through Arnold's brain as he stood talking with Natasha. He saw at once why she had only that one name. It was enough, and it was not long before he learnt that it was the symbol of an authority in the Circle that admitted of no question.

She was the envoy of him whose word was law, absolute and irrevocable, to every member of the Brotherhood; to disobey whom was death; and to obey whom had, so far at least, meant swift and invariable success, even where it seemed least to be hoped for.

Of course, Natasha's almost girlish question about the airship was really a command, which would have been none the less binding had she only had her own beauty to enforce it. As she spoke the President and Colston -- who had only lost himself for the time behind a mask and cloak -- came up to Arnold and asked him if he was prepared to give an exhibition of the powers of his model, and to explain its working and construction to the Circle at once.

He replied that everything was perfectly ready for the trial, and that he would set the model working for them in a few minutes. The President then told him that the exhibition should take place in another room, where there would be much more space than where they were, and bade him bring the box and follow him.

A door was now opened in the wall of the room remote from that by which he and Colston had entered, and through this the whole party went down a short passage, and through another door at the end which opened into a very large apartment, which, from the fact of its being windowless, Arnold rightly judged to be underground, like the Council-chamber that they had just left.

A single glance was enough to show him the chief purpose to which the chamber was devoted. The wall at one end was covered with arm-racks containing all the newest and most perfect makes of rifles and pistols; while at the other end, about twenty paces distant, were three electric signalling targets, graded, as was afterwards explained to him, to one, three, and five hundred yards range.

In a word, the chamber was an underground range for rifle and pistol practice, in which a volley could have been fired without a sound being heard ten yards away. It was here that the accuracy of the various weapons invented from time to time was tested; and here, too, every member of the Circle, man and woman, practised with rifle and pistol until an infallible aim was acquired. A register of scores was kept, and at the head of it stood the name of Radna Michaelis.

A long table ran across the end at which the arm-racks were, and on this Arnold laid the case containing the model, he standing on one side of the table, and the members of the Circle on the other, watching his movements with a curiosity that they took no trouble to disguise.

He opened the case, feeling something like a scientific demonstrator, with an advanced and critical class before him. In a moment the man disappeared, and the mechanician and the enthusiast took his place. As each part was taken out and laid upon the table, he briefly explained its use; and then, last of all, came the hull of the air-ship

This was three feet long and six inches broad in its midships diameter. It was made in two longitudinal sections of polished aluminium, which shone like burnished silver. It would have been cigar-shaped but for the fact that the forward end was drawn out into a long sharp ram, the point of which was on a level with the floor of the hull amidships as it lay upon the table. Two deep bilge-plates, running nearly the whole length of the hull, kept it in an upright position and prevented the blades of the propellers from touching the table. For about half its whole length the upper part of the hull was flattened and formed a deck from which rose three short strong masts each of which carried a wheel of thin metal whose spokes were six inclined fans something like the blades of a screw.

A little lower than this deck there projected on each side a broad, oblong, slightly curved sheet of metal, very thin, but strengthened by means of wire braces, till it was as rigid as a plate of solid steel, although it only weighed a few ounces. These air-planes worked on an axis amidships, and could be inclined either way through an angle of thirty degrees. At the pointed stern there revolved a powerful four-bladed propeller, and from each quarter, inclined slightly outwards from the middle line of the vessel projected a somewhat smaller screw working underneath the after end of the air-planes.

The hull contained four small double-cylinder engines, one of which actuated the stern-propeller, and the other three the fan-wheels and side-propellers. There were, of course, no furnaces, boilers, or condensers. Two slender pipes ran into each cylinder from suitably placed gas reservoirs, or power-cylinders, as the engineer called them, and that was all.

Arnold deftly and rapidly put the parts together, continuing his running description as he did so, and in a few minutes the beautiful miracle of ingenuity stood complete before the wondering eyes of the Circle, and a murmur of admiration ran from lip to lip, bringing a flush of pleasure to the cheek of its creator.

"There," said he, as he put the finishing touches to the apparatus, " you see that she is a combination of two principles -- those of the Aëronef and the Aëroplane. The first reached its highest development in Jules Verne's imaginary "Clipper of the Clouds," and the second in Hiram Maxim's Aëroplane. Of course, Jules Verne's Aëronef was merely an idea, and one that could never be realised while Robur's mysterious source of electrical energy remained unknown -- as it still does.

"Maxim's Aëroplane is, as you all know, also an unrealised ideal so far as any practical use is concerned. He has succeeded in making it fly, but only under the most favourable conditions, and practically without cargo. Its two fatal defects have been shown by experience to be the comparatively overwhelming weight of the engine and the fuel that he has to carry to develop sufficient power to rise from the ground and progress against the wind, and the inability of the machine to ascend perpendicularly to any required height.

"Without the power to do this no air-ship can be of any use save under very limited conditions. You cannot carry a railway about with you, or a station to get a start from every time you want to rise, and you cannot always choose a nice level plain in which to come down. Even if you could the Aëroplane would not rise again without its rails and carriage. For purposes of warfare, then, it may be dismissed as totally useless.

"In this machine, as you see, I have combined the two principles. These helices on the masts will lift the dead weight of the ship perpendicularly without the slightest help from the side-planes, which are used to regulate the vessel's flight when afloat. I will set the engines that work them in motion independently of the others which move the propellers, and then you will see what I mean."

As he spoke, he set one part of the mechanism working. Those watching saw the three helices begin to spin round, the centre one revolving in an opposite direction to the other two, with a soft whirring sound that gradually rose to a high-pitched note.

When they attained their full speed they looked like solid wheels, and then the air-ship rose, at first slowly, and then more and more swiftly, straight up from the table, until it strained hard at the piece of cord which prevented it from reaching the roof.

A universal chorus of "bravas" greeted it as it rose, and every eye became fixed on it as it hung motionless in the air, sustained by its whirling helices. After letting it remain aloft for a few minutes Arnold pulled it down again, saying as he did so--

"That, I think, proves that the machine can rise from any position where the upward road is open, and without the slightest assistance of any apparatus. Now it shall take a voyage round the room.

"You see it is steered by this rudder-fan under the stern propeller. In the real ship it will be worked by a wheel, like the rudder of a sea-going vessel; but in the model it is done by this lever, so that I can control it by a couple of strings from the ground."

He went round to the other side of the table while he was speaking, and adjusted the steering gear, stopping the engines meanwhile. Then he put the model down on the floor, set all four engines to work, and stood behind with the guiding-strings in his hands. The spectators heard a louder and somewhat shriller whirring noise than before, and the beautiful fabric, with its shining, silvery hull and side-planes, rose slantingly from the ground and darted forward down the room, keeping Arnold at a quick run with the rudder-strings tightly strained.

Like an obedient steed, it instantly obeyed the slightest pull upon either of them, and twice made the circuit of the room before its creator pulled it down and stopped the machinery.

The experiment was a perfect and undeniable success in every respect, and not one of those who saw it had the slightest doubt as to Arnold's air-ship having at last solved the problem of aërial navigation, and made the Brotherhood lords of a realm as wide as the atmospheric ocean that encircles the globe.

As soon as the model was once more resting on the table, the President came forward and, grasping the engineer by both hands, said in a voice from which he made but little effort to banish the emotion that he felt--

"Bravo, brother! Henceforth you shall be known to the Brotherhood as the Master of the Air, for truly you have been the first among the sons of men to fairly conquer it. Come, let us go back and talk, for there is much to be said about this, and we cannot begin too soon to make arrangements for building the first of our aërial fleet. You can leave your model where it is in perfect safety, for no one ever enters this room save ourselves."

So saying the President led the way to the Council-chamber, and there, after the Ariel -- as it had already been decided to name the first air-ship -- had been christened in anticipation in twenty-year old champagne, the Circle settled down at once to business, and for a good three hours discussed the engineer's estimate and plans for building the first vessel of the aërial fleet.

At length all the practical details were settled, and the President rose in token of the end of the conference. As he did so he said somewhat abruptly to Arnold--

"So far so good. Now there is nothing more to be done but to lay those plans before the Chief and get his authority for withdrawing out of the treasury sufficient money to commence operations. I presume you could reproduce them from memory if necessary -- at any rate, in sufficient outline to make them perfectly intelligible?"

"Certainly," was the reply. "I could reproduce them in fac simile without the slightest difficulty. Why do you ask?"

"Because the Chief is in Russia, and you must go to him and place them before him from memory. They are far too precious to be trusted to any keeping, however trustworthy. There are such things as railway accidents, and other forms of sudden death, to say nothing of the Russian customs, false arrests, personal searches, and imprisonments on mere suspicion.

"We can risk none of these, and so there is nothing for it but your going to Petersburg and verbally explaining them to the Chief. You can be ready in three days, I suppose?"

"Yes, in two, if you like," replied Arnold, not a little taken aback at the unexpected suddenness of what he knew at once to be the first order that was to test his obedience to the Brotherhood. "But as I am absolutely ignorant of Russia and the Russians, I suppose you will make such arrangements as will prevent my making any innocent but possibly awkward mistakes."

"Oh yes," replied the President, with a smile, "all arrangements have been made already, and I expect you will find them anything but unpleasant. Natasha goes to Petersburg in company with another lady member of the Circle whom you have not yet seen.

"You will go with them, and they will explain everything to you en route, if they have no opportunity of doing so before you start. Now let us go upstairs and have some supper. I am famished, and I suppose every one else is too."

Arnold simply bowed in answer to the President; but one pair of eyes at least in the room caught the quick, faint flush that rose in his cheek as he was told in whose company he was to travel. As for himself, if the journey had been to Siberia instead of Russia, he would have felt nothing but pleasure at the prospect after that.

They left the Council-chamber by the passage and the ante-room, the sentry standing to attention as they passed him, each giving the word in turn, till the President came last and closed the doors behind him. Then the sentry brought up the rear and extinguished the lights as he left the passage.

Fifteen minutes later there sat down to supper, in the solidly comfortable dining-room of the upper house, a party of ladies and gentlemen who chatted through the meal as merrily and innocently as though there were no such things as tyranny or suffering in the world, and whom not the most acute observer would have taken for the most dangerous and desperately earnest body of conspirators that ever plotted the destruction, not of an empire, but of a civilisation and a social order that it had taken twenty centuries to build up.

SUPPER was over about eleven, and then the party adjourned to the drawing-room, where for an hour or so Arnold sat and listened to such music and singing as he had never heard in his life before. The songs seemed to be in every language in Europe, and he did not understand anything like half of them, so far, at least, as the words were concerned.

They were, however, so far removed from the average drawing-room medley of twaddle and rattle that the music interpreted the words into its own universal language, and made them almost superfluous.

For the most part they were sad and passionate, and once or twice, especially when Radna Michaelis was singing, Arnold saw tears well up into the eyes of the women, and the brows of the men contract and their hands clench with sudden passion at the recollection of some terrible scene or story that was recalled by the song.

At last, close on midnight, the President rose from his seat and asked Natasha to sing the "Hymn of Freedom." She acknowledged the request with an inclination of her head, and then as Radna sat down to the piano, and she took her place beside it, all the rest rose to their feet like worshippers in a church.

The prelude was rather longer than usual, and as Radna played it Arnold heard running through it, as it were, echoes of all the patriotic songs of Europe from "Scots Wha Hae" and "The Shan van Voght" to the forbidden Polish National Hymn and the Swiss Republican song, which is known in England as "God Save the Queen." The prelude ended with a few bars of the "Marseillaise," and then Natasha began.

It was a marvellous performance. As the air changed from nation to nation the singer changed the language, and at the end of each verse the others took up the strain in perfect harmony, till it sounded like a chorus of the nations in miniature, each language coming in its turn until the last verse was reached.

Then there was silence for a moment, and then the opening chords of the "Marseillaise" rang out from the piano, slow and stately at first, and then quickening like the tread of an army going into battle.

Suddenly Natasha's voice soared up, as it were, out of the music, and a moment later the Song of the Revolution rolled forth in a flood of triumphant melody, above which Natasha's pure contralto thrilled sweet and strong, till to Arnold's intoxicated senses it seemed like the voice of some angel singing from the sky in the ears of men, and it was not until the hymn had been ended for some moments that he was recalled to earth by the President saying to him--

"Some day, perhaps, you will be floating in the clouds, and you will hear that hymn rising from the throats of millions gathered together from the ends of the earth, and when you hear that you will know that our work is done, and that there is peace on earth at last."

"I hope so," replied the engineer quietly, "and, what is more, I believe that some day I shall hear it."

"I believe so too," suddenly interrupted Radna, turning round on her seat at the piano, "but there will be many a battle-song sung to the accompaniment of battle-music before that happens. I wish "--

"That all Russia were a haystack, and that you were beside it with a lighted torch," said Natasha, half in jest and half in earnest.

"Yes, truly!" replied Radna, turning round and dashing fiercely into the "Marseillaise" again.

"I have no doubt of it. But, come, it is after midnight, and we have to get back to Cheyne Walk. The princess will think we have been arrested or something equally dreadful. Ah, Mr. Colston, we have a couple of seats to spare in the brougham. Will you and our Admiral of the Air condescend to accept a lift as far as Chelsea?"

"The condescension is in the offer, Natasha," replied Colston, flushing with pleasure and glancing towards Radna the while. Radna answered with an almost imperceptible sign of consent, and Colston went on: "If it were in an utterly opposite direction"--

"You would not be asked to come, sir. So don't try to pay compliments at the expense of common sense," laughed Natasha before he could finish. "If you do you shall sit beside me instead of Radna all the way."

There was a general smile at this retort, for Colston's avowed devotion to Radna and the terrible circumstances out of which it had sprung was one of the romances of the Circle.

As for Arnold, he could scarcely believe his ears when he heard that he was to ride from Clapham Common to Chelsea sitting beside this radiantly beautiful girl, behind whose innocence and gaiety there lay the shadow of her mysterious and terrible parentage.

Lovely and gentle as she seemed, he knew even now how awful a power she held in the slender little hand whose nervous clasp he could still feel upon his own, and this knowledge seemed to raise an invisible yet impassable barrier between him and the possibility of looking upon her as under other circumstances it would have been natural for a man to look upon so fair a woman.

Natasha's brougham was so far an improvement on those of the present day that it had two equally comfortable seats, and on these the four were cosily seated a few minutes after the party broke up. To Arnold, and, doubtless, to Colston also, the miles flew past at an unheard-of speed; but for all that, long before the carriage stopped at the house in Cheyne Walk, he had come to the conviction that, for good or evil, he was now bound to the Brotherhood by far stronger ties than any social or political opinions could have formed.

After they had said good-night at the door, and received an invitation to lunch for the next day to talk over the journey to Russia, he and Colston decided to walk to the Savoy, for it was a clear moonlit night, and each had a good deal to say to the other, which could be better and more safely said in the open air than in a cab. So they lit their cigars, buttoned up their coats, and started off eastward along the Embankment to Vauxhall.

"Well, my friend, tell me how you have enjoyed your evening, and what you think of the company," said Colston, by way of opening the conversation.

"Until supper I had a very pleasant time of it. I enjoyed the business part of the proceedings intensely, as any other mechanical enthusiast would have done, I suppose. But I frankly confess that after that my mind is in a state of complete chaos, in the midst of which only one figure stands out at all distinctly."

"And that figure is?"

"Natasha. Tell me -- who is she?"

"I know no more as to her true identity than you do, or else I would answer you with pleasure."

"What! Do you mean to say "--

"I mean to say just what I have said. Not only do I not know who she is, but I do not believe that more than two or three members of the Circle, at the outside, know any more than I do. Those are, probably, Nicholas Roburoff, the President of the Executive, and his wife, and Radna Michaelis."

"Then, if Radna knows, how comes it that you do not know? You must forgive me if I am presuming on a too short acquaintance; but it certainly struck me to-night that you had very few secrets from each other."

"There is no presumption about it, my dear fellow," replied Colston, with a laugh. "It is no secret that Radna and I are lovers, and that she will be my wife when I have earned her."

"Now you have raised my curiosity again," interrupted Arnold, in an inquiring tone.

"And will very soon satisfy it. You saw that horrible picture in the Council-chamber? Yes. Well, I will tell you the whole story of that some day when we have more time; but for the present it will be enough for me to tell you that I have sworn not to ask Radna to come with me to the altar while a single person who was concerned in that nameless crime remains alive.

"There were five persons responsible for it to begin with -- the governor of the prison, the prefect of police for the district, a spy, who informed against her, and the two soldiers who executed the infernal sentence. It happened nearly three years ago, and there are two of them alive still -- the governor and the prefect of police.

"Of course the Brotherhood would have removed them long ago had it decided to do so; but I got the circumstances laid before Natas, by the help of Natasha, and received permission to execute the sentences myself. So far I have killed three with my own hand, and the other two have not much longer to live.

"The governor has been transferred to Siberia, and will probably be the last that I shall reach. The prefect is now in command of the Russian secret police in London, and unless an accident happens he will never leave England."

Colston spoke in a cold, passionless, merciless tone, just as a lawyer might speak of a criminal condemned to die by the ordinary process of the law, and as Arnold heard him he shuddered. But at the same time the picture in the Council-chamber came up before his mental vision, and he was forced to confess that men who could so far forget their manhood as to lash a helpless woman up to a triangle and flog her till her flesh was cut to ribbons, were no longer men but wild beasts, whose very existence was a crime. So he merely said--

"They were justly slain. Now tell me more about Natasha."

"There is very little more that I can tell you, I'm afraid. All I know is that the Brotherhood of the Terror is the conception and creation of a single man, and that that man is Natas, the father of Natasha, as she is known to us. His orders come to us either directly in writing through Natasha, or indirectly through him you have heard spoken of as the Chief."

"Oh, then the Chief is not Natas?"

"No, we have all of us seen him. In fact, when he is in London he always presides at the Circle meetings. You would hardly believe it, but he is an English nobleman, and Secretary to the English Embassy at Petersburg."

"Then he is Lord Alanmere, and an old college friend of mine!" exclaimed Arnold. "I saw his name in the paper the night before last. It was mentioned in the account of the murder"--

"We don't call those murders, my friend," drily interrupted Colston; "we call them what they really are-- executions."

"I beg your pardon; I was using the phraseology of the newspaper. What was his crime?"

"I don't know. But the fact that the Chief was there when he died is quite enough for me. Well, as I was saying, the Chief, as we call him, is the visible and supreme head of the Brotherhood so far as we are concerned. We know that Natas exists, and that he and the Chief admit no one save Natasha to their councils.

"They control the treasury absolutely, and apart from the contributions of those of the members who can afford to make them, they appear to provide the whole of the funds. Of course, Lord Alanmere, as you know, is enormously wealthy, and probably Natas is also rich. At any rate, there is never any want of money where the work of the Brotherhood is concerned.

"The estimates are given to Natasha when the Chief is not present, and at the next meeting she brings the money in English gold and notes, or in foreign currency as may be required, and that is all we know about the finances.

"Perhaps I ought to tell you that there is also a very considerable mystery about the Chief himself. When he presides at the Council meetings he displays a perfectly marvellous knowledge of both the members and the working of the Brotherhood.

"It would seem that nothing, however trifling, is hidden from him; and yet when any of us happen to meet him, as we often do, in Society, he treats us all as the most perfect strangers, unless we have been regularly introduced to him as ordinary acquaintances. Even then he seems utterly ignorant of his connection with the Brotherhood.

"The first time I met him outside the Circle was at a ball at the Russian Embassy. I went and spoke to him, giving the sign of the Inner Circle as I did so. To my utter amazement, he stared at me without a sign of recognition, and calmly informed me, in the usual way, that I had the advantage of him.

"Of course I apologised, and he accepted the apology with perfect good humour, but as an utter stranger would have done. A little later Natasha came in with the Princess Ornovski, whom you are going to Russia with, and who is there one of the most trusted agents of the Petersburg police. I told her what had happened.

"She looked at me for a moment rather curiously with those wonderful eyes of hers; then she laughed softly, and said, 'Come, I will set that at rest by introducing you; but mind, not a word about politics or those horrible secret societies, as you value my good opinion.'

"I understood from this that there was something behind which could not be explained there, where every other one you danced with might be a spy, and I was introduced to his lordship, and we became very good friends in the ordinary social way; but I failed to gather the slightest hint from his conversation that he even knew of the existence of the Brotherhood.

"When we left I drove home with Natasha and the Princess to supper, and on the way Natasha told me that his Lordship found it necessary to lead two entirely distinct lives, and that he adhered so rigidly to this rule that he never broke it even with her. Since then I have been most careful to respect what, after all, is a very wise, if not an absolutely necessary, precaution on his part."

"And, now," said Arnold, speaking in a tone that betrayed not a little hesitation and embarrassment, "if you can do so, answer me one more question, and do so as shortly and directly as you can. Is Natasha in love with, or betrothed to, any member of the Brotherhood as far as you know?"

Colston stopped and looked at him with a laugh in his eyes. Then he put his hand on his shoulder and said--

"As I thought, and feared! You have not escaped the common lot of all heart-whole men upon whom those terrible eyes of hers have looked. The Angel of the Revolution, as we call her among ourselves, is peerless among the daughters of men. What more natural, then, that all the sons of men should fall speedy victims to her fatal charms? So far as I know, every man who has ever seen her is more or less in love with her -- and mostly more!

"As for the rest, I am as much in the dark as you are, save for the fact that I know, on the authority of Radna, that she is not betrothed to any one, and, so far as she knows, still in the blissful state of maiden fancy-freedom."

"Thank God for that!" said Arnold, with an audible sigh of relief. Then he went on in somewhat hurried confusion, "But there, of course, you think me a presumptuous ass, and so I am; wherefore"--

"There is no need for you to talk nonsense, my dear fellow. There never can be presumption in an honest man's love, no matter how exalted the object of it may be. Besides, are you not now the central hope of the Revolution, and is not yours the hand that shall hurl destruction on its enemies?

"As for Natasha, peerless and all as she is, has not the poet of the ages said of just such as her--

She's beautiful, and therefore to be woo'd;
She is a woman: therefore to be won?

"And who, too, has a better chance of winning her than you will have when you are commanding the aerial fleet of the Brotherhood, and, like a very Jove, hurling your destroying bolts from the clouds, and deciding the hazard of war when the nations of Europe are locked in the death-struggle? Why, you see such a prospect makes even me poetical.

"Seriously, though, you must not consider the distance between you too great. Remember that you are a very different person now to what you were a couple of days ago. Without any offence, I may say that you were then nameless, while now you have the chance of making a name that will go down to all time as that of the solver of the greatest problem of this or any other age.

"Added to this, remember that Natasha, after all, is a woman, and, more than that, a woman devoted heart and soul to a great cause, in which great deeds are soon to be done. Great deeds are still the shortest way to a woman's heart, and that is the way you must take if you are to hope for success."

"I will!" simply replied Arnold, and the tone in which the two words were said convinced Colston that he meant all that they implied to its fullest extent.

IT was nearly eleven the next morning by the time Arnold and Colston had finished breakfast. This was mostly due to the fact that Arnold had passed an almost entirely sleepless night, and had only begun to doze off towards morning. The events of the previous evening kept on repeating themselves in various sequences time after time, until his brain reeled in the whirl of emotions that they gave rise to.

Although of a strongly mathematical and even mechanical turn of mind, the young engineer was also an enthusiast, and therefore there was a strong colouring of romance in his nature which lifted him far above the level upon which his mere intellect was accustomed to work.

Where intellect alone was concerned -- as, for instance, in the working out of a problem in engineering or mechanics -- he was cool, calculating, and absolutely unemotional. His highly-disciplined mind was capable of banishing every other subject from consideration save the one which claimed the attention of the hour and of incorporating itself wholly with the work in hand until it was finished.

These qualities would have been quite sufficient to assure his success in life on conventional lines. They would have made him rich, and perhaps famous, but they would never have made him a great inventor; for no one can do anything really great who is not a dreamer as well as a worker.

It was because he was a dreamer that he had sacrificed everything to the working out of his ideal, and risked his life on the chance of success, and it was for just the same reason that the tremendous purposes of the Brotherhood had been able to fire his imagination with luridly brilliant dreams of a gigantic world-tragedy in which he, armed with almost supernatural powers, should play the central part.

This of itself would have been enough to make all other considerations of trivial moment in his eyes, and to bind him irrevocably to the Brotherhood. He saw, it is true, that a frightful amount of slaughter and suffering would be the price either of success or failure in so terrific a struggle; but he also knew that that struggle was inevitable in some form or other, and whether he took a part in it or not.

But since the last sun had set a new element had come into his life, and was working in line with both his imagination and his ambition. So far he had lived his life without any other human love than what was bound up with his recollections of his home and his boyhood. As a man he had never loved any human being. Science had been his only mistress, and had claimed his undivided devotion, engrossing his mind and intellect completely, but leaving his heart free.

And now, as it were in an instant, a new mistress had come forward out of the unknown. She had put her hand upon his heart, and, though no words of human speech had passed between them, save the merest commonplaces, her soul had said to his, "This is mine. I have called it into life, and for me it shall live until the end."

He had heard this as plainly as though it had been said to him with the lips of flesh, and he had acquiesced in the imperious claim with a glad submission which had yet to be tinged with the hope that it might some day become a mastery.

Thus, as the silent, sleepless hours went by, did he review over and over again the position in which he found himself on the threshold of his strange new life, until at last physical exhaustion brought sleep to his eyes if not to his brain, and he found himself flying over the hills and vales of dreamland in his air-ship, with the roar of battle and the smoke of ruined towns far beneath him, and Natasha at his side, sharing with him the dominion of the air that his genius had won.

At length Colston came in to tell him that the breakfast was spoiling, and that it was high time to get up if they intended to be in time for their appointment at Chelsea. This brought him out of bed with effective suddenness, and he made a hasty toilet for breakfast, leaving more important preparations until afterwards.

During the meal their conversation naturally turned chiefly on the visit that they were to pay, and Colston took the opportunity of explaining one or two things that it was necessary for him to know with regard to the new acquaintance that he was about to make at Chelsea.

"So far as the outside world is concerned," said he, "Natasha is the niece of the Princess Ornovski. She is the daughter of a sister of hers, who married an English gentleman, named Darrel, who was drowned with his wife about twelve years ago, when the Albania was wrecked off the coast of Portugal. The Princess had a sister, who was drowned with her husband in the Albania, and she left a daughter about Natasha's then age, but who died of consumption shortly after in Nice.

"Under these circumstances, it was, of course, perfectly easy for the Princess to adopt Natasha, and introduce her into Society as her niece as soon as she reached the age of coming out.

"This has been of immense service to the Brotherhood, as the Princess is, as I told you, one of the most implicitly trusted allies of the Petersburg police. She is received at the Russian Court, and is therefore able to take Natasha into the best Russian Society, where her extraordinary beauty naturally enables her to break as many hearts as she likes and to learn secrets which are of the greatest importance to the Brotherhood.

"Her Society name is Fedora Darrel, and it will scarcely be necessary to tell you that outside our own Circle no such being as Natasha has any existence."

"I perfectly understand," replied Arnold. "The name shall never pass my lips save in privacy, and indeed it is hardly likely that it will ever do so even then, for your habit of calling each other by your Christian names is too foreign to my British insularity."

"It is a Russian habit, as you, of course, know, and added to that, we are, so far as the Cause is concerned, all brothers and sisters together, and so it comes natural to us. Anyhow, you will have to use it with Natasha, for in the Circle she has no other name, and to call her Miss Darrel there would be to produce something like an earthquake."

"Oh, in that case, I daresay I shall be able to avoid the calamity, though there will seem to be a presumption about it that will not make me very comfortable at first."

"Too much like addressing one's sweetheart, eh?"

This brought the conversation to a sudden stop, for Arnold's only reply to it was a quick flush, and a lapse into silence that was a good deal more eloquent than any verbal reply could have been. Colston noticed it with a smile, and got up and lit a pipe.

For the first time for a good few years Arnold took considerable pains with his toilet that morning. A new fit-out had just been delivered by a tailor who had promised the things within twenty-four hours, and had kept his word. The consequences were that he was able to array himself in perfect morning costume, from his hat to his boots, and that was what it had not been his to do since he left college.

Colston had recommended him in his easy friendly way to pay scrupulous attention to externals in the part that he would henceforth have to play before the world. He fully saw the wisdom of this advice, for he knew that, however well a part may be played, if it is not dressed to perfection, some sharp eyes will see that it is a part and not a reality.

The playing of his part was to begin that day, and he recognised that at least one of the purposes of his visit to Natasha was the determining of what that part was to be. He thus looked forward with no little curiosity to the events of the afternoon, quite apart from the supreme interest that centred in his hostess. They started out nearly a couple of hours before they were due at Cheyne Walk, as they had several orders to give with regard to Arnold's outfit for the journey that was before him; and this done, they reached the house about a quarter of an hour before lunch time.

They were received in the most delightful of sitting-rooms by a very handsome, aristocratic-looking woman, who might have been anywhere between forty and fifty. She shook hands very cordially with Arnold, saying as she did so--

"Welcome, Richard Arnold! The friends of the Cause are mine, and I have heard much about you already from Natasha, so that I already seem to know you. I am very sorry that I was not able to be at the Circle last night to see what you had to show. Natasha tells me that it is quite a miracle of genius."

"She is too generous in her praise," replied Arnold, speaking as quietly as he could in spite of the delight that the words gave him. "It is no miracle, but only the logical result of thought and work. Still, I hope that it will be found to realise its promise when the time of trial comes."

"Of that I have no doubt, from all that I hear," said the Princess. "Before long I shall hope to see it for myself. Ah, here is Natasha. Come, I must introduce you afresh, for you do not know her yet as the world knows her."

Arnold heard the door open behind him as the Princess spoke, and, turning round, saw Natasha coming towards him with her hand outstretched and a smile of welcome on her beautiful face. Before their hands met the Princess moved quietly between them and said, half in jest and half in earnest--

"Fedora, permit me to present to you Mr. Richard Arnold, who is to accompany us to Russia to inspect the war-balloon offered to our Little Father the Tsar. Mr. Arnold, my niece, Fedora Darrell There, now you know each other."

"I am delighted to make your acquaintance, Mr. Arnold," said Natasha, with mock gravity as they shook hands. "I have heard much already of your skill in connection with aërial navigation, and I have no doubt but that your advice will be of the greatest service to his Majesty."

"That is as it may be," answered Arnold, at once entering into the somewhat grim humour of the situation. "But if it is possible I should like to hear something a little definite as to this mission with which I have been, I fear, undeservingly honoured. I have been very greatly interested in the problem of aërial navigation for some years past, but I must confess that this is the first I have heard of these particular war-balloons."

"It is for the purpose of enlightening you on that subject that this little party has been arranged," said the Princess, turning for the moment away from Colston, with whom she was talking earnestly in a low tone. "Ha! There goes the lunch-bell. Mr. Colston, your arm. Fedora, will you show Mr. Arnold the way?"

Arnold opened the door for the Princess to go out, and then followed with Natasha on his arm. As they went out, she said in a low tone to him--

"I think, if you don't mind, you had better begin at once to call me Miss Darrel, so as to get into the way of it. A slip might be serious, you know."

"Your wishes are my laws, Miss Darrel," replied he, the name slipping as easily off his tongue as if he had known her by it for months. It may have been only fancy on his part, he thought he felt just the lightest, imaginable pressure on his arm as he spoke. At any rate, he was vain enough or audacious enough to take the impression for a reality, and walked the rest of the way to the dining-room on air.

The meal was dainty and perfectly served, but there were no servants present, for obvious reasons, and so they waited on themselves. Colston sat opposite the Princess and carved the partridges, while Arnold was vis-à-vis to Natasha, a fact which had a perceptible effect upon his appetite.

"Now," said the Princess, as soon as every one was helped, "I will enlighten you, Mr. Arnold, as to your mission to Russia. One part of the business, I presume, you are already familiar with?" Arnold bowed his assent, and she went on--

"Then the other is easily explained. Interested as you are in the question, I suppose there is no need to tell you that for several years past the Tsar has had an offer open to all the world of a million sterling for a vessel that will float in the air, and be capable of being directed in its course as a ship at sea can be directed."

"Yes, I am well aware of the fact. Pray proceed." As he said this Arnold glanced across the table at Natasha, and a swift smile and a flash from her suddenly unveiled eyes told him that she, too, was thinking of how the world's history might have been altered had the Tsar's million been paid for his invention. Then the Princess went on--

"Well, through a friend at the Russian Embassy, I have learnt that a French engineer has, so he says, perfected a balloon constructed on a new principle, which he claims will meet the conditions of the Tsar's offer.

"My friend also told me that his Majesty had decided to take an entirely disinterested opinion with regard to this invention, and asked me if I could recommend any English engineer who had made a study of aërial navigation, and who would be willing to go to Russia, superintend the trials of the war-balloon, and report as to their success or otherwise.

"This happened a few days ago only, and as I had happened to read an article that you will remember you wrote about six months ago in the Nineteenth, or, as it is now called, the Twentieth Century, I thought of your name, and said I would try to find some one. Two days later I got news from the Circle of your invention -- never mind how; you will learn that later on -- and called at the Embassy to say I had found some one whose judgment could be absolutely relied upon. Now, wasn't that kind of me, to give you such a testimonial as that to his Omnipotence the Tsar of All the Russias?"

Once more Arnold bowed his acknowledgments -- this time somewhat ironically, and Natasha interrupted the narrative by saying with a spice of malice in her voice--

"No doubt the Little Father will duly recognise your kindness, Princess, when he gets quite to the bottom of the matter."

"I hope he will," replied the Princess, "but that is a matter of the future -- and of considerable doubt as well." Then, turning to Arnold again, she continued--

"You will now, of course, see the immense advantage there appeared to be in getting you to examine these war-balloons. They are evidently the only possible rivals to your own invention in the field, and therefore it is of the utmost importance that you should know their strength or their weakness, as the case may be.

"Well, that is all I have to say, so far. It has been decided that you shall go, if you are willing, with us to Petersburg the day after to-morrow to see the balloon, and make your report. All your expenses will be paid on the most liberal scale, for the Tsar is no niggard in spending either his own or other people's money, and you will have a handsome fee into the bargain for your trouble."

"So far as the work is concerned, of course, I undertake it willingly," said Arnold, as the Princess stopped speaking. "But it hardly seems to me to be right that I should take even the Tsar's money under such circumstances. To tell you the truth, it looks to me rather uncomfortably like false pretences."

Again Natasha's eyes flashed approval across the table, but nevertheless she said--

"You seem to forget, my friend, that we are at war with the Tsar, and all's fair in -- in love and war. Besides, if you have any scruples about keeping the fee for your professional services -- which, after all, you will render as honestly as though it were the merest matter of business -- you can put it into the treasury, and so ease your conscience. Remember, too," she went on more seriously, "how the enormous wealth of this same Tsar has swollen by the confiscation of fortunes whose possessors had committed no other crime than becoming obnoxious to the corrupt bureaucracy."

"I will take the fee if I fairly earn it, Miss Darrel," replied Arnold, returning the glance as he spoke, "and it shall be my first contribution to the treasury of the Brotherhood."

"Spoken like a sensible man," chimed in the Princess. " After all, it is no worse than spoiling the Egyptians, and you have scriptural authorit