When the secret agent of His Majesty's Minister of Police selected Hippolyte Darnier to he his messenger for the occasion, he knew he had a man whom he could trust.

   Darnier was married: he was a man of middle age, who had served the Republic first, then the Consulate and finally the Emperor with unswerving loyalty, in circumstances which more often than not entailed grave personal risks. He had always extricated himself from difficult and dangerous positions with marvellous coolness and acumen, and it was but natural that when the autograph letter signed by M. de Trevargan--which implicated the noble Marquis and his family in the late abortive conspiracy against the life of the Emperor--had to be sent to M. le Duc d'Otrante, the latter's secret agent should choose a man of proven courage and address for the purpose.

   The Man in Grey took leave of his messenger at his lodgings in the Rue de Bras, and at the very last moment of the leave-taking gave him the precious letter, which Darnier immediately secreted in the inside breast pocket of his coat. Then he was ready for the journey.

   In those days the Paris diligence started from the Hotel du Portugal in Caen every morning at eight o'clock, reaching Lisieux--the first stage--at five in the afternoon. Darnier had secured his seat on the banquette by the side of the driver, for although the day was cold, he felt that he would be safer there than huddled up between other passengers in the interior, some of whom might be unpleasantly light-fingered. There was a fair number of travellers that morning. An elderly pair of bourgeois on their way to Evreux and a well-to-do shopkeeper's wife going to Paris to visit her son, who was employed in the new aerial telegraphs, had secured the coupe' in front. Two or three commercial travellers, a couple of young officers on leave from the war, a portly fishwife from Caen and a round-cheeked country wench occupied the interior. At the small posting inn of the "Mouton Noir," just outside the city, another woman got in. She had no luggage and apparently she had not booked her place, for she had to be content with one on the narrow back seat of the inside, wedged in between the round-faced country wench and the fishwife from Caen. However, the newcomer seemed quite satisfied with her surroundings: she sat down placidly and, pulling her hood well over her face, took up a book and thereafter remained absorbed in reading, looking neither to right nor left, and taking no part in the vapid conversation, engendered by boredom, which was carried on around her. Her fellow-travellers put her down as belonging to some sort of religious community, for she wore a voluminous black cloak with a hood which only allowed the point of her chin to peep out below it.

   At Mezidon, where halt was made for dinner, everyone trooped into the coffee-room of the "Cheval Blanc." Hippolyte Darnier asked to have his meal served in a private room, and as he was provided with special credentials bearing the seal of the Ministry of Police, his wishes were at once acceded to, and he was served both promptly and obsequiously, in a small room adjoining the one where the other passengers were dining together.

   The woman in the black cloak had been the last to leave the diligence. She had remained in her seat, immersed in her book till everyone had scrambled out of the coach. Then she, too, got out, and walked very slowly in the wake of the jovial party ahead. But she did not appear to be in any hurry to join her fellow-travellers, for while they settled down with noise and bustle at the well-spread table, she strolled away in the direction of the river.

   The dinner was over and coffee had been handed round when she entered the coffee-room. The wine had been good, and everyone was hilarious. As she closed the door behind her, she was greeted with jovial calls.

   "Here, reverend sister, come and sit down."

   "You must be famished!"

   "This roasted gigot is positively excellent!"

   But the woman paid no heed to these well-meant suggestions, beyond a few whispered "Thank you's." Her hood still covered her face, all but the point of her chin, after the manner adopted by professed nuns of cloistered orders when men are about. She crossed the coffee-room rapidly to the door of the private room beyond, where Hippolyte Darnier was having his solitary dinner.

   The serving-maid tried to stop her.

   "There's a gentleman in there," she said, "who wishes to be alone."

   "Oh!" said the woman quietly, "that is quite all right. I am travelling in his company."

   With that she opened the door and went into the inner room. There was so much noise going on in the coffee-room at the time that no one was able to state positively afterwards how Darnier greeted the intruder, and whether or no her statement was true that she was travelling in his company. Certain it is that, after a quarter of an hour or so, she came out again, as quietly, as silently as she had come, re-crossed the coffee-room, and went out, leaving this time a curious, almost uncanny air of mystery behind her.

   "I have never been fond of these female callotins myself," said one of the young officers after a while.

   "I cannot stand people who make no noise when they walk," asserted the worthy bourgeois of Evreux.

   The well-to-do farmer's wife, conscious of undisputed respectability, added with some acidity:

   "Strange that a professed nun should be travelling alone in a man's company."

   After that comments on the occurrence became freer and more ribald, and very soon the absentee had not a shred of reputation left in the minds of the worthy but intensely bored people congregated around the festive board of the "Cheval Blanc."

   At two o'clock the ostler in charge announced that the diligence was ready to start. Jean Baptiste, the jocund host of the "Cheval Blanc," was going round the table, collecting payment for the good dejeuner which had been served to his well-satisfied clients.

   "What shall I do about the gentleman in there?" asked the serving maid, pointing to the door of the private room. "He was asleep the last time I went in."

   "Wake him up," replied Jean Baptiste.

   "I have done all I could to wake him," answered the wench. "He doesn't seem inclined to move."

   "He'll have to move," rejoined Jean Baptiste with a laugh; "or the diligence will go without him."

   With that he strode across to the door of the private room, kicked it open with his foot, and called out in his lusty voice which, as someone remarked, was loud enough to wake the dead:

   "Now then, Monsieur, 'tis time to wake up! The diligence is about to start. You'll never get to Paris at this rate."

   The door had remained wide open. The travellers in the coffee-room could see the figure of M. Darnier sitting huddled in a chair, and half-leaning against the table, like one who is in a drunken sleep.

   "Give him a good shake, papa Baptiste!" called one of the young officers waggishly. "Your good wine has been too much for him."

   Jean Baptiste stooped and gave the huddled figure a good shake. Then suddenly he uttered a horrified "Oh, mon Dieu!"

   "What is it?" queried the travellers anxiously.

   "The man is dead!"

   Never had the Paris diligence been so late in starting from Mezidon; and when finally, with much cracking of whip and rattling of chains, it thundered along the cobblestones of the Grande Rue, it was without its full complement of passengers.

   M. le Commissaire de Police had ordered the detention of most of them as witnesses of the occurrences which culminated in the death of Hippolyte Darnier, who was known to the commissaire as an employe' on the police staff at Caen.

   It was no use grumbling. No one who had seen or spoken to the woman in the black cloak could be allowed to leave the city until M. le Procureur Imperial in Caen had granted them leave to do so.

   In the meanwhile M. le Sous-Prefet, who was quite hopelessly out of his depth, interrogated the witnesses without eliciting more than a noisy and confused account of the events of the past few hours wherein the weather, the bad state of the roads, and the good wines of the "Cheval Blanc" vied in importance with the doings of a so-called mysterious nun, of whom nothing had been seen by anybody save the point of a chin and a voluminous black cloak and hood. By the time that the sous-prefet had jotted down these miscellaneous depositions, it was discovered that the mysterious personage in question had disappeared. Whereupon search parties were sent abroad in every direction, with strict orders to bring any woman who was seen wearing any kind of a black cloak forthwith before M. le Commissaire, whilst the sous-prefet, freely perspiring under the effort, wrote out a detailed and wholly unintelligible report of the incidents, which he dispatched by mounted courier to his chief at Caen.

   The search parties, after two or three hours' diligent scouring of the neighbourhood, brought back an inoffensive farm servant, who was trudging home from her milking, wrapped in a black shawl; the kitchen wench from the Hotel de Madrid, who had gone out to meet her sweetheart and had borrowed her mistress's black cloak for the occasion; and old Madame Durand, the caretaker at the church of St. Pierre, who always wore a black gown as an outward symbol of her official position and responsible calling.

   One lad, more intelligent than the rest, while wandering along the tow-path of the river, had espied a black cloak and hood floating down-stream until its progress was arrested by a clump of rushes. The lad fished for the cloak with a barge-pole and succeeded in landing it. He brought it in triumph to Mezidon, where he became the hero of the hour.

   Late in the evening M. Laurens, prefet of Caen, received his subordinate's report. At once he communicated with M. Carteret, the chief commissary of police. The two, fearing that the officious secret agent would keep them out of their beds for the next two hours, with God knows what orders to proceed to Mezidon in the middle of the night, decided to say nothing to him until the morning. After all, the matter was not of such paramount importance. Darnier, they argued, had had too much to drink and had a fit of apoplexy in an overheated room.

   But next morning, when the chief commissary did present himself before the Minister's agent with the Mezidon report, he for one felt that he would far sooner have sacrificed a night's rest than endure the icy reprimand and the coolly worded threats wherewith the insufferable little man had greeted his news.

   "By your culpable negligence," the Minister's agent had said in his quiet monotone which made every official conscious of some unavowed peccadillo shiver, "you have given the murderer an added chance of escape."

   "The murderer!" protested M. Carteret, with a feeble attempt at swagger. "What in the world makes you think that Darnier has been murdered? Why, the leech--"

   "Because an ignorant country apothecary finds no sign of violence upon a dead body," retorted the Man in Grey coldly, "unanswerable logic must not be deemed at fault."

   "But what motive could anyone have for murdering poor Darnier?" argued the commissary with a shrug of his wide shoulders.

   "You forget that he was the bearer of an important report from me to the Minister," replied the Man in Grey.

   The commissary gave a long, low whistle. He certainly had forgotten that all-important fact for the moment.

   "And you think," he said, "that the woman in the black cloak was an emissary of those cursed Chouans, and that she murdered Darnier in order to steal that report--"

   "Together with the autograph letter of Monsieur le Marquis de Trevargan which implicates him and his family in the plot against the Emperor," broke in the secret agent. "I should have thought it was self-evident."

   He wasted no further argument on the commissary, who, bewildered and helpless, solemnly scratched his head, as if to extricate therefrom a solution of the weird mystery.

   An hour or so later Madame Darnier, the widow of the murdered man, called at the prefecture in answer to a hurried summons. As someone must break the terrible news to her, the Man in Grey undertook the task, speaking as sympathetically and as gently as he could. She was a delicate-looking woman, still in the prime of life, and with justified pretensions to good looks. She took the news badly, for, as she explained later when she was calmer, she had been devoted to her husband and he to her, and they had only been married five years. She had no children, she said, in answer to the secret agent's kindly inquiries, and her dear husband's death left her practically without means of support. The assurance that His Majesty's Minister of Police would provide generously for the widow of a man who had died in the service of the State gave her some small measure of comfort, and when she finally took her leave, she appeared, if not more consoled, at any rate more tranquil.

   Madame Darnier had been unable to furnish the police with any clue which might guide them in their investigations. She was quite sure that her husband had no enemies, and whilst she had been aware that his work often entailed grave personal risks, she knew nothing about the work itself, nor, in this case, had he told her anything beyond the fact that he was going to Paris and would be absent about ten days. She repudiated with indignation the suggestion that he had been travelling in the company of some woman unknown to herself, and of her own accord threw out the suggestion that some of those mechant Chouans--knowing her husband's connection with the police--had not scrupled to slay him.

   The Chateau de Trevargan, situated upon a lonely piece of coast midway between the mouths of the Orne and the Dives and about ten or a dozen miles from Caen, had remained one of the beauty spots of the neighbourhood. Though its owners had emigrated at the outbreak of the Revolution and their domain had become the property of the State, it had been bought nominally by a man named Leclerc, who had been the Marquis's agent, and who held it thence-forward and administered it with unswerving loyalty, in the name of his former master. Leclerc with his wife and family had settled down in the chateau, and together they looked after the house, the park and the estate during the Marquis's prolonged absence abroad. They always appeared plentifully supplied with money, which no doubt came to them through one of the many agencies in Jersey, and when M. le Marquis returned to France some five years ago he found his house in perfect order; and it is supposed that he rewarded his faithful steward generously, for the latter retired with his family to a little estate close by, where they continued to live in undiminished affluence.

   M. le Marquis de Trevargan had obviously not brought a fortune back from exile; nevertheless, he and Madame la Marquise kept up a good deal of style at the chateau. They also went to Paris and made their obeisance to the Emperor at Versailles, and hitherto not the slightest suspicion of disloyalty to the new regime had attached to them.

   The discovery of the outrageous plot against the life of the Emperor during the latter's visit to Caen the previous month, had left the Trevargans unscathed, even though close upon a score of their personal friends were implicated in the affair. It was only three weeks later that M. le Marquis learned that the one foolish letter he had written in the whole course of his cautious career had fallen into the hand of the police. He had written to his friend the Comte de Romorantin, urging him to keep aloof from the conspirators until he was sure that the Corsican had really been sent to Hades.

   "Madame la Marquise and myself do not intend to appear at Caen until we know for certain that the coup has been successful. We have done our share in the matter of providing funds, but we prefer to let Blue-Heart, White-Beak and the other ruffians do the work for us. We shall be ready to proclaim His Majesty King Louis XVIII in the Hotel de Ville as soon as we know that all fear of failure or discovery is at an end. I entreat you to do likewise and to destroy this letter as soon as read."

   Unfortunately, M. de Romorantin had not destroyed the letter. He had it in his pocket at the very moment when the police made the raid on the house in the Rue aux Juifs and arrested the Chouan conspirators red-handed. The letter was seized, together with every other paper which happened to be in the possession of the prisoners, and it was that same highly compromising letter which Hippolyte Darnier was taking to Paris when he died so mysteriously in the private room of the "Cheval Blanc" at Mezidon.

   Investigation at the chateau on the day following the discovery of the plot had led to no result. M. le Marquis watched with lofty indifference and disdain the turning over of his private papers and belongings by the heedless hands of the police. Except for that one letter, he had never committed an indiscretion or written an unguarded word in his life. But there was the letter! And it was this very search which, coming as a bolt from the blue, had assured him that he was no longer immune from suspicion.

   The day following the death of Hippolyte Darnier, M. le Marquis de Trevargan received another visit from the police, this time in the person of M. Carteret, the commissary, whom he knew personally, and who came accompanied by a small, insignificant-looking personage dressed in grey. Once more, secure in the knowledge that nothing that could in any way compromise him existed inside his chateau, the Marquis received his visitors with condescending hauteur.

   "Ah, ca, my good Carteret," he said to the commissary somewhat tartly, "when am I and Madame la Marquise to be free from this insolent interference? Since when are the loyal subjects of His Majesty to be treated as if they were criminals?"

   The worthy M. Carteret felt hot and cold all over. He had an enormous regard for M. le Marquis de Trevargan and a wholesome terror of the Minster's secret agent, and between the two he did not know to which saint he should pray for protection.

   "Loyalty is a matter of degree," here interposed the Man in Grey in his usual monotone; "as Monsieur le Marquis well knows."

   "I only know, Monsieur," retorted the Marquis haughtily, "that certain aspersions have been cast upon my good name, chiefly on the strength of a forged letter--"

   "A forged letter, Monsieur le Marquis?" interposed the Man in Grey with a smile. "Monsieur de Romorantin has owned to its authenticity."

   "Monsieur de Romorantin was scared out of his wits," rejoined the Marquis, "or he never would have been taken in by such a clumsy forgery. And," he added haughtily, "I challenge you to produce it, so that at least I might have a chance of proving the truth of what I say."

   "It is just because the letter has been stolen," stammered M. Carteret, "and the messenger murdered that we are here to-day, Monsieur le Marquis."

   While he spoke a door at the farther end of the room opened, and a tall, handsome woman appeared upon the threshold. When the commissary finished speaking, she broke into a ringing laugh.

   "A pretty story indeed!" she said harshly. "A monstrous accusation hurled at Monsieur le Marquis de Trevargan! And when he demands to be confronted with proofs of his guilt, these proofs are said to be destroyed, whilst a vague hint of murder goes to swell the iniquitous charge. A pretty pass, indeed!" she continued, as with stately steps she advanced into the room. "Fortunately His Majesty has some friendship for Monsieur le Marquis and myself, and we can appeal to him to punish those who have put this affront upon us."

   "Your pardon, Madame la Marquise," answered the Man in Grey, as soon as she had finished her impassioned tirade. "Monsieur le Commissaire said that the letter had been stolen; he did not say that it had been destroyed."

   An almost imperceptible shadow seemed to pass as in a flash over the Marquise's handsome face; but the very next second she shrugged her handsome shoulders and said flippantly:

   "The same thing, my good man."

   "I trust not, Madame la Marquise," rejoined the Man in Grey.

   "Oh, we all know," here interrupted M. le Marquis with a sneer, "that in your unavowable profession, Monsieur, you are bound to send a certain number of unfortunates to what you call justice, whether they are guilty or not, or you would lose your highly lucrative employment. Isn't that so?"

   "Our employment, Monsieur le Marquis," replied the Man in Grey imperturbably, "is not likely to find favour in your sight."

   "Well!" rejoined Madame with a harsh laugh, "so long as you don't trump up a charge of murder against some poor innocent this time--"

   "Murder, Madame la Marquise!" queried the secret agent with a look of mild astonishment in his colourless eyes. "Who spoke of murder?"

   "I thought," parried the Marquise airily, "that some spy or other of yours was murdered and robbed of the forged letter, which was supposed to convict Monsieur le Marquis de Trevargan and myself of disloyalty.

   "One of our men was certainly robbed of a letter written by Monsieur le Marquis de Trevargan to Monsieur de Romorantin on the eve of the conspiracy against the Emperor," said the Man in Grey, "but I am happy to say that he is alive at the present moment--"

   A terrific crash of broken china drowned the rest of his speech. The table against which Madame la Marquise had been leaning fell over, scattering precious bibelots in every direction.

   "How clumsy of me!" exclaimed Madame in some confusion, whilst the commissary of police, agitated and obsequious, crawled about on his hands and knees trying to collect the fragments of priceless china which littered the carpet.

    "Do not trouble, I pray you, Monsieur le Commissaire," said the Marquise with affable condescension. "The servant will clear away the rubbish."

   She sank into a chair, as if tired out with the interminable interview, and put her aristocratic hand up to her mouth, smothering a yawn.

   "As you were saying, Monsieur--er--" she drawled wearily.

   "I was not saying anything, Madame la Marquise," rejoined the Man in Grey, smiling.

   "Your spy or messenger, whatever he was," interposed the Marquis impatiently. "You were saying something about him."

   "Oh! nothing that would interest Monsieur le Marquis," replied the secret agent. "He was stabbed in the hand with a pin steeped in a deadly arrow poison, which in ordinary circumstances would have killed him in less than five minutes. Fortunately for him the assassin was either inexperienced or clumsy, or perhaps the poison had become stale by keeping. At any rate, poor Hippolyte Darnier was nearly killed--but not quite. He is still very ill--half paralysed; but the leech assures me that he will recover."

   This time there was no mistaking the shadow which once more passed across the Marquise's handsome face, whilst for the space of a second or two the somewhat high colour of her cheeks changed to a leaden hue. The Marquis instinctively came forward a few steps, obtruding his stately figure between the police agent and his wife. Next moment, however, Madame had regained her composure. She rose from her chair, tall, dignified, unspeakably haughty.

   "So much the better for your friend, Monsieur--er--I forget your name," she said coldly. "And now," she added as she walked majestically towards the door, "if you or Monsieur le Commissaire have any more senseless questions to ask, you must be content with the information Monsieur le Marquis condescends to give you. I confess to being weary of this folly."

   She pushed open the door and sailed out of the room, as arrogant as any Queen of the old regime dismissing an importunate courtier. Then the door fell to behind her and her firm step soon died away along the marble corridor.

   The commissary of police was pining to take his leave, and much to his relief the Man in Grey put no further questions to M. le Marquis, and after a few seconds declared himself ready to go. M. de Trevargan was quite pleasant to poor M. Carteret, who obviously greatly disapproved of this intrusion on the privacy of the stately chateau.

   "The man is a veritable pest!" he contrived to whisper in the Marquis's ear, behind the back of the secret agent. "I would wish to assure Monsieur le Marquis--"

   "Do not trouble to do that, my good Monsieur Carteret," interrupted M. de Trevargan impatiently. "Your assurances are unnecessary. You were obeying orders: and the man, I suppose, was fulfilling what he believed to be his duty."

   Somewhat comforted, the commissary went down-stairs in the wake of the Man in Grey, who was waiting for him in the vast entrance hall below, and was gazing in rapt admiration at the pictures and statuary which would not have shamed a royal residence.

   "It is a rare treat," he was saying to the pompous majordomo who was waiting to usher the visitors out, "for art-lovers to have the opportunity of seeing these priceless treasures. Are they not sometimes shown to the public?"

   "Oh, no, Monsieur," replied the majordomo sententiously. "As Monsieur and Madame de Trevargan are in residence, it would not be seemly to allow strangers to wander about the chateau."

   "Ah!" said the Man in Grey, "then my sister was lucky indeed. She saw all these beautiful pictures and statues yesterday!"

   "Yesterday, Monsieur?" queried the man, as haughtily as his master and mistress would have done. "I do not understand."

   "It's quite simple," rejoined the secret agent. "My sister is the intimate friend of one of the maids here, and yesterday, as Madame la Marquise was away all day, this friend smuggled my sister into this part of the chateau and showed her all these marvellous art treasures--"

   "This would be a pretty story, Monsieur," here broke in the majordomo impatiently, "if it were based on some semblance of truth. Madame la Marquise did not happen to be away all day yesterday."

   "But surely--" protested the Man in Grey.

   "Madame la Marquise was indeed very much at home," continued the other with becoming sternness, "seeing that she entertained the children of the Convent School here to dejeuner at midday and games all the afternoon."

   The secret agent now appeared overwhelmed with confusion at his stupid blunder.

   "I am very sorry," he murmured haltingly. "There's some mistake on my part--I understood my sister to say that she was here yesterday--it must have been some other day--"

   "Very likely!" retorted the majordomo with a sneer; and giving the plebeian police agent the supercilious stare which so much impertinence deserved, he finally closed the monumental doors of the chateau upon the unwelcome visitors.

   "Another snub!" remarked the commissary of police as he descended the steps beside his silent colleague. "And why you trumped up that story about your sister and a maid, I cannot imagine!" he added with withering contempt.

   But the Man in Grey apparently did not hear him. He was murmuring under his breath:

   "Clever enough to have secured an alibi! I might have guessed it! And such an actress! But, then, how in Heaven's name was it done? How? And by whom?"

   The Man in Grey had allowed the commissary of police to return to Caen, but he seemed to find it impossible to tear himself away from the neighbourhood of Trevargan. He felt that the lordly chateau held a grim secret within its walls, and he could not rest until he had wrung it from them.

   All day he hung about the approaches of the park and, as soon as night fell, managed to creep into the depths of the shrubberies before the gates were closed. Here he remained on the watch, peering through the thicket at the stately pile, the windows of which soon became lighted from within, one by one. What he expected to see he could not have told you, but Night is the great guardian of dark mysteries and unavowable deeds, and the secret agent hoped that the gloom would mayhap give him the key to that riddle which had baffled him in broad light of day.

   From where he was crouching he commanded a view both of the front of the house and of the path which led to the back. He had been lying in wait for nearly two hours, and a neighbouring church clock had just struck ten, when through the darkness he perceived the figure of a woman, wrapped in a cloak, walking quickly towards the chateau. At first he thought it might be one of the maids returning from a walk, but as the figure passed close to him, something vaguely familiar in the poise of the head and the shape of the cloak, caused him suddenly to crawl out of his hiding-place as noiselessly as he could, and to follow the woman until a bend in the avenue afforded him the opportunity which he sought. In one second he had taken off his mantle and, springing on her from behind, he caught her in his arms and threw the mantle over her head, smothering the cry which had risen to her lips. Though he was short and slight, he had uncommon strength, and the woman was small and slender. He lifted her off the ground and carried her along the avenue and down a side-path, until he had reached a secluded portion of the park.

   Here he laid his burden down and unwound the mantle which was stifling her. Then he turned the light of his dark lantern upon her.

   "Madame Darnier!" he murmured. "Just as I thought!"

   Then, as the woman was still lying there almost unconscious, he threw back her cloak and looked at her hands. There was nothing in them. He felt for the pockets in her cloak and in her dress; his hands wandered over the folds of her gown; his ears, attuned to the slightest sound, listened for the crackling that would reveal the presence of papers concealed about her person. But there was nothing, and he frowned in deep puzzlement as he encountered her large, melancholy eyes, which were following his every movement with the look of a trapped animal watching its captor.

   "What are you doing here in Trevargan?" he asked sternly.

   "Help me to get up," she replied almost fiercely, "and I may tell you."

   More puzzled than before, he raised her to her feet.

   "You remember me?" he asked.

   "Of course," she replied. "How could I forget the man who first held the cup of such bitter sorrow to my lips?"

   "Someone had to tell you," he rejoined more gently, "and your husband was in my employ."

   "And died in your employ," she answered roughly.

   "Will you believe me," he retorted, "that, had I known of the terrible risk which he was running, I would have undertaken the errand myself?"

   "Yes," she said dully, "I know that you are not a coward."

   "Will you tell me why you are here?" he reiterated firmly.

   She looked round her, right into the gloom in the direction where the lights of the chateau glimmered feebly through the trees. Then, turning to the Man in Grey, she said calmly: "There was a suspicion gnawing at my heart. I came to see if I could confirm it, or lull it for ever to rest."

   "You suspect the Trevargans of having had a hand in the outrage against your husband?"

   "Don't you?" she retorted.

   He made no reply and even through the darkness she could see that he appeared deeply buried in thought. He had turned off the light of his lantern, and by the dim light of the moon, partly hidden behind a veil of clouds, they could only distinguish one another's outline against the dense background of the shrubberies.

   "Will you allow me to escort you home?" he asked abruptly.

   She nodded in assent, and he, knowing the way, guided her along the less frequented paths of the park till he came to a locked postern gate. Asking her to wait a moment and, drawing a small tool from his pocket, he coolly picked the lock, and a moment or two later he and Mme. Darnier were walking rapidly down the main road in the direction of the city.

   Next morning, when the Man in Grey arrived at the commissariat of police, he was greeted with sneers and acid reproaches by M. Carteret and M. le Prefet.

   "I must say," said the latter with becoming pomposity, "that your attitude with regard to Monsieur and Madame de Trevargan is exceedingly reprehensible. You have placed my colleague and myself in a very awkward position. Monsieur le Marquis is one of the most influential, as he has always been one of the most loyal, personages in the province, and I have no doubt that he will visit his displeasure upon us both, though, Heaven knows! we have done nothing but follow your foolish lead in the matter."

   "I pray you have patience, my good Monsieur Laurens," said the Man in Grey with unruffled calm. "The matter to which you refer is on the point of reaching its culmination."

   "I was alluding to the affair of Hippolyte Darnier," said the prefet.

   "So was I," retorted the Man in Grey.

   "Are you about to discover who murdered him?" queried M. Carteret, with a touch of taunt.

   "Yes," replied the secret agent. "With the help of Madame Darnier, whom I have summoned hither."

   The prefet shrugged his shoulders with marked impatience.

   "And I must ask you," added the Man in Grey in his blandest tones which admitted of no argument, "not to interfere in anything I may say to Madame Darnier in the course of our interview; to express no surprise and, above all, not to attempt to contradict. And you know, Monsieur Laurens, and you, too, Monsieur le Commissaire," he added sternly, "that when I give an order I intend it to be obeyed."

   Hardly had this peremptory command fallen from his lips than Madame Darnier was announced.

   She came in, looking even more fragile and more delicate in her deep mourning than she had done before. Her large, melancholy eyes sought, as if appealingly, those of the three men who had half-risen to greet her. The Man in Grey offered her a chair, into which she sank.

   "You sent for me, Monsieur?" she asked, as she pressed a black-bordered handkerchief to her quivering lips.

   "Only to give you the best of news, Madame," the secret agent said cheerily.

   "The best of news?" she murmured. "I do not understand."

   "My friend Hippolyte Darnier," he exclaimed, "your husband, Madame, is out of danger--"

   She rose suddenly, as if some hidden spring had projected her to her feet, and stood rigid and tense, her cheeks the colour of yellow wax, her eyes so dilated that they seemed as black as coal. The prefet and the commissaire had, indeed, the greatest difficulty to maintain the attitude of impassivity which the Minister's agent had so rigidly prescribed.

   "Out of danger," murmured Mme. Darnier after a while. "What do you mean?"

   "No wonder you are overcome with emotion, Madame," rejoined the secret agent. "I myself did not dare breathe a word to you of my hopes at Trevargan last night, for I had not had the leech's final pronouncement. But I have had hopes all along. We transported your dear husband's inanimate body to my lodgings after his--er--accident the other day. He was totally unconscious; it almost seemed as if rigor mortis had already set in. But I suppose the deadly arrow poison, which a murderous hand had injected with the aid of a pin, was either stale or ineffectual. Certain it is that my dear friend Darnier rallied, that he is alive at this moment, and that I shall have the pleasure of conducting you to his bedside immediately."

   While he spoke the Man in Grey had kept his eyes fixed steadily upon the woman. She was still standing as rigid as before and clinging with one hand to the back of the chair, whilst with the other she continued to press her handkerchief to her lips. Nor could the other two men detach their eyes from her face, which appeared like a petrified presentation of abject and nameless horror.

   "Darnier," continued the Man in Grey relentlessly, "is slowly regaining consciousness now. The leech desires that the first sight which greets his eyes should be that of his beloved wife. Come, Madame, it is a short walk to my lodgings. Let me conduct you--Ah!" he suddenly exclaimed, as with his usual agility he literally threw himself upon the staggering woman. "Drop that, now! Drop it, I say!"

   But he was too late. Madame Darnier had fallen back into her chair. From a deep scratch across her hand drops of blood were oozing freely. The commissaire and the prefet were gazing, horror-stricken and helpless, upon her face, which was slowly becoming distorted. A curious, jerky quiver shook her limbs from time to time.

   "She has killed herself with the same poison wherewith she sent her unfortunate husband to his death," said the secret agent quietly.

   "To his death?" gasped the prefet "Then the story of Hippolyte Darnier's recovery--"

   "Was false," broke in the Man in Grey. "It was a trap set to wring an avowal from the murderer. And we must own," he added earnestly, "that the avowal has been both full and conclusive."

   He threw his mantle over the wretched woman, who was already past help. But he dispatched one of the servants of the prefecture for the nearest leech.

   "But what made you guess--?" queried the commissary who was gasping with astonishment.

   "The fact that Madame Darnier was the daughter of the man Leclerc, who for years devoted himself to the fortunes of the Trevargans. He and his family are devoted heart and soul to the Marquis and his cause. The daughter has proved herself a fanatic, a madwoman, I. should say. She killed her husband to save the family she loved."

   "But those accursed Trevargans--" said the prefet.

   "Their punishment will not long be delayed. I sent a copy of the compromising letter to the Minister--the original is still in my keeping."