One evening in the January of 1745, the critical year of Fontenoy and of the great Jacobite rising, a middle-aged gentleman, the private secretary of a Secretary of State, was working as usual in the room of a house in Cleveland Row. The table at which he sat was littered with papers, but at this precise moment he had leaned back in his chair with a puzzled expression and his left hand in perplexity pushed his wig awry.

“Extraordinary,” he muttered, “most extraordinary.” The remark was apparently caused by an official letter in his other hand—a letter marked “Most Private,” which came from The Hague, and the passage which he had just read ran:

On the table lay the cipher communication together with a decoded version which the secretary now studied for the third time. In explicit language the despatch supplied detailed information as to certain recent highly confidential negotiations between the Jacobite party in Paris and the French King, Louis XV., a revelation in short of the most weighty state secrets of the French Government.

“‘No. 101,’” the secretary murmured, scratching his head, “always ‘No. 101.’ It is marvellous, incredible. How the devil can it be done?”

But there was no answer to this question, save the fact which provoked it—that closely ciphered paper with its disquieting information so curiously and mysteriously obtained.

“Ah.” He jumped up and hurriedly straightened his wig. “Good-evening to you.”

The new-comer was a man of about five-and-thirty, tall, finely built, and of a muscular physique, with a face of considerable power. Most noticeable, perhaps, in his appearance was his air of disciplined reserve, emphasised in his strong mouth and chin, but almost belied by the glow in his large, dark eyes, which looked you through and through with a strangely watchful innocence.

“There is work to be done, sir?” he asked as he took the chair offered.

“Exactly. To-day we have received most gratifying and surprising information from our friend ‘No. 101’—and we have the promise of more.”

“Yes.” The brief monosyllable was spoken almost softly, but the dark eyes gleamed, as they roamed over the room.

“The communications from ‘No. 101’ have begun again,” the secretary pursued; “that in itself is interesting. The Secretary of State therefore desired me to send at once for you, the most trustworthy secret agent we have. In a very few minutes Captain Statham of the First Foot Guards will be here—”

“Sent, I think, from the Low Countries at the request of our agents at The Hague?”

“Ah, I see you are as well informed as usual. You are quite right. Are you,” he laughed, “ever wrong?”

The spy paused. “The communications then from ‘No. 101’ concern the military operations?” was all he said.

“Not yet. But,” he almost laughed, “we have a promise they will. You know the situation. This will be a critical year in Flanders. Great Britain and her allies propose to make a great, an unprecedented effort; his Royal Highness the Duke of Cumberland will have the supreme command. Unhappily the French under the Maréchal de Saxe apparently propose to make even greater efforts. With such a general as the Maréchal against us we cannot afford to neglect any means, fair or foul, by which his Royal Highness can defeat the enemy.”

“Then you wish me to assist ‘No. 101’ in betraying the French plans to our army under the Duke of Cumberland?”

“Not quite,” the other replied; “we cannot spare you as yet. But you have had dealings with this mysterious cipher, and we ask you to place all your experience at the disposal of Captain Statham.”

“I agree most willingly,” was the prompt answer.

“This curious ‘No. 101,’” continued the secretary slowly, “you do not know personally, I believe?”

The other was looking at him carefully but with a puzzled air.

“I ask because—because I am deeply curious.”

“I am as curious as yourself, sir. ‘No. 101’ is to me simply a cipher number,—nothing more, nothing less.”

“I feared so,” said the secretary. “But is it not incredible? The information sent always proves to be accurate, but there is never a trace of how, why, or by whom it is obtained.”

“That is so. Secrecy is the condition on which alone we get it. We pay handsomely—we obtain the truth—and we are left in the dark.”

“Shall we ever discover the secret, think you?”

“I am sure not.” The tone was conviction itself.

At this moment Captain Statham was ushered in, a typical English gentleman and officer, ruddy of countenance, blue-eyed, frankness and courage in every line of his handsome face and of his athletic figure.

“Captain Statham—Mr. George Onslow of the Secret Service—” the secretary began promptly, adding with a laugh as the two shook hands: “Ah, I see you have met before. I am not surprised. Mr. Onslow knows everybody and everything worth knowing.” He gathered up a bundle of papers. “That is the communication from ‘No. 101’ and the covering letter. And now, gentlemen, I will leave you to your business.” He bowed and left the room.

Onslow took the chair he had vacated and for a quarter of an hour Captain Statham and he chatted earnestly on the position of affairs in the Low Countries, and the war then raging from the Mediterranean to the North Sea, on the vast efforts being made by the French for a great campaign in the coming spring, the military genius of the famous Maréchal de Saxe, the Austrian and Dutch allies of Great Britain, and the new English royal commander-in-chief who was shortly to leave to take over the work of saving Flanders from the arms of Louis XV. Onslow then briefly explained what the Secret Service agents of the Duke of Cumberland were to expect and why.

“Communications,” he wound up, “from this mysterious spy and traitor, ‘No. 101,’ invariably come like bolts from the blue. They are, of course, always in cipher and they will reach you by the most innocent hands—a peasant, a lackey, a tavern wench—sometimes you will simply find them, say, under your pillow, or in your boots. No one can tell how they get there. But never neglect them, however strange or unusual their contents may be, for they are never wrong—never! The genuine ones you will recognise by this mark—” he took up the ciphered paper and put his fingers on a sign—“two crossed daggers and the figures 101 written in blood—you see—so”:

Captain Statham stared at the sign, entranced.

“A soldier,” Onslow remarked with his slow smile, “can always distinguish blood from red ink—is it not so?” Statham nodded. “Remember, then, those crossed daggers with the figures in blood are the only genuine mark. All others are forgeries—reject them unhesitatingly. Let me show it you again.” He produced from his pocket-book a paper with the design in the corner, which, when compared with the one on the table, corresponded exactly.

“I warn you,” Onslow added, “because the existence of this ‘No. 101’ is becoming known to the French—they suspect treachery—their Secret Service is clever and they may attempt to deceive you. As they do not know the countersign, though they may have guessed at the treachery of ‘No. 101’ they cannot really hoodwink you. Cipher papers which come in the name of ‘101’ without that remarkable signature are simply a nom de guerre, of politics, of love, of anything you like, but they are either a forgery or a trap; so put them in the fire.”

Statham sat pondering, his eyes riveted on the crossed daggers. “You, sir,” he began, “have had dealings with this mysterious person. Is it a man or a woman?”

“Ah!” Onslow laughed gently. “Every one asks that, every man at least. I cannot answer; no one, indeed, can. My opinion? Well, I change it every month. But these are the facts: It is absolutely certain that the traitor insists on high, very high pay; absolutely certain that he or she has access to the very best society in Paris and at the Court, and is at home in the most confidential circles of the King and his ministers. We have even had documents from the private cabinet of Louis XV. Furthermore, the traitor can convey the information in such a way as to baffle detection. If it is a woman she is a very remarkable one; if it be a man he is one who controls important women. Perhaps it is both. Such knowledge, so peculiar, so accurate, so extensive, such skill and such ingenuity scarcely seem to be within the powers of any individual man or woman.”

“Every word you say sharpens my surprise and my curiosity.”

“Yes, and every transaction you will have with the cipher will sharpen it more and more. I have been fifteen years in the Secret Service, but this business is to-day as much a puzzle as it ever was, for ‘No. 101’ has taught me a very important secret, one unknown even to the French King’s ministers, which, so jealously guarded as it is, may never be discovered in the King’s lifetime or at all. Can you really believe that Louis, while professing to act through his ministers, has stealthily built up a little secret service of his own whose work is to spy on those ministers, on his ambassadors, generals, and their agents, to receive privately instructions wholly different from what the King has officially sanctioned, and frequently directly to thwart, check, annul, and defeat by intrigue and diplomacy the official policy of their sovereign?”

“Is it possible?”

“It is a fact,” Onslow said, emphatically. “But the King, ‘No. 101,’ you and I and one or two others alone know it. Let me give you a proof. To-day officially Louis through his ministers has disavowed the Jacobites. The ministers believe their master is sincere; many of them regret it, but their instructions are explicit. In truth, through those private agents I spoke of, the King is encouraging the Jacobites in every way and is actually thwarting the steps and the policy which he has officially and publicly commanded.”

“And the ministers are ignorant of this?”

“Absolutely. But mark you, unless the King is very careful, some day there will come an awkward crisis. His Majesty will be threatened with the disclosure of this secret policy which has his royal authority, but which gives the lie to his public policy, equally authentic. And unless he can suppress the first he must be shown to be doubly a royal liar—not to dwell on the consequences to France.”

“What a curious king!” Statham ejaculated.

“Curious!” Onslow laughed softly; “more than curious, because no one knows the real Louis. The world says he is an ignorant, superstitious, indolent, extravagant, heartless dullard in a crown who has only two passions—hunting and women. It is true; he is the prince of hunters and the emperor of rakes. But he is also a worker, cunning, impenetrable, obstinate, remorseless.”

“But why does he play such a dangerous game?”

“God knows. The real Louis no man has discovered, or woman either; he is known only to the Almighty or the devil. But you observe what chances this double life gives to our friend ‘No. 101.’”

Statham began to pace up and down. “What are the traitor’s motives?” he demanded, abruptly.

“Ah, there you beat me.” Onslow rose and confronted him. “My dear sir, a traitor’s motives may be gold, or madness, ambition, love, jealousy, revenge, singly or together, but above all love and revenge.”

Statham made an impatient gesture. “I would give my commission,” he exclaimed, “to know the meaning of this mystery.”

A sympathetic gleam lingered in Onslow’s eyes as he calmly scrutinised the young officer. “Ah,” he said, almost pityingly, “you begin to feel the spell of this mystery wrapped in a number, the spell of ‘No. 101,’ the fatal spell.”

“Fatal?” Statham took him up sharply.

“Yes. I must warn you. Every single person who, in his dealings with this cipher, has got near to the heart of the truth has so far met with a violent end. It is not pleasant, but it is a fact. And the explanation is easy. Those who might betray the truth are removed by accident or design, some by this method, some by that. They pass into the silence of the grave, perhaps just when they could have revealed what they had discovered.” He paused, for Statham was visibly impressed. “Really there is no danger,” he added; “but I say as earnestly as I can, because you are young, and life is sweet for the young, for God’s sake stifle your curiosity, resist the spell—that fatal spell. Take the information as it comes, and ask no questions, push no inquiries, however tempting and easy the path to success seems, or, as sure as I stand here, His Majesty King George the Second will lose a promising and gallant officer.”

Statham walked away and resumed his seat. “And you, Mr. Onslow?” he demanded, looking up with the profoundest interest.

“Do I practise what I preach? Well, I am a spy by profession: to some men such a life is everything—it is, at least, to me. But I do not conceal from myself that if my curiosity overpowers me my hour for silence, too, will come—the silence of the unknown grave in an unknown land.”

“Then is no one ever to know?” Statham muttered with childish petulance.

“Probably not. A hundred years hence the secret that baffles you and me will baffle our successors.”

Statham’s heels tapped on the floor. “Perhaps,” he pronounced, slowly, “perhaps the truth is well worth the price that is paid for it—death and the silence of the grave.”

Onslow stared at him. His eyes gleamed curiously as if they were fixed on visions known only to the inner mind. “Perhaps,” he repeated gravely. “But really,” he added, with a sudden lightness, “there is no one to persuade us it is so. Come, Captain Statham, you have not forgotten supper, I hope, and that I propose to introduce you to-night to the most seductive enchantress in London?”

“No, indeed. All day I have been hungering for that supper. In the Low Countries we do not get suppers presided over by ladies such as you have described to me.”

“In the French army they have both the ladies and the suppers,” Onslow replied, laughing. “And, my dear Captain, to the victors of the spring will fall the spoils. To-night shall be a foretaste, and if my enchantress does not make you forget ‘No. 101,’ I despair of the gallantry of British officers.”

He locked up the papers, chatting all the time, and then the two gentlemen went out together.