On the morning of the third of January the mail which reached Mr. Barnes contained several letters of interest to those who follow this history. The first which he opened was very brief. It read:

"If Mr. Barnes will call at his earliest convenience he will greatly oblige

Emily Remsen."

He read this twice, and then took up another, which was as follows:

"J. Barnes, Esq.:

"Dear Sir: I take the liberty of recalling to your mind the conversation which I had with you last month. I regret very much that I should have hinted that there was any possibility that my friend Mr. Mitchel might be implicated in the Pullman car robbery. As you know, Miss Emily Remsen was robbed at the festival, night before last, of a ruby pin worth $20,000. It is very evident to my mind that Mr. Mitchel's hand is in this. I know that he pretends to be sick at a hotel in Philadelphia, but may not that be a humbug? It would have been easy enough for him to slip over, don one of the Forty Thieves dominos, take the gem, and get back to Philadelphia the same night. This would be a safe theft for him to commit, especially as he may have the assistance of Miss Remsen. Now as all is fair in a bet, I want you to undertake to prove for me that Mr. Mitchel committed this theft. I want to win that wager from him, and don't mind spending money. Even if I should advance you the whole thousand, I should save my own, provided you convict him within a year. Besides, the satisfaction to me would be worth the money. It takes a sharp man to get ahead of Mr. Mitchel. I enclose a check for two hundred, as a sort of retainer, and you may draw on me for more, up to one thousand dollars if you should need it. By the way, whilst writing to you I may as well confess that I was wrong in my suspicion of Mr. Thauret. I am sure that he does not cheat at cards. I have watched him frequently since then, and he certainly plays a square game. I have no reason for liking the man, and as a fact dislike him most heartily. Nevertheless justice compels me to retract the imputation which I put upon him. Another thing: the partner with whom he played that night I told you was unknown to me. I have since made his acquaintance, and though he is poor, he is a gentleman, and above suspicion. His name is Adrian Fisher. Hoping you will help me to win my wager,

Yours truly,
"Arthur Randolph."

"So," thought Mr. Barnes, "even Mr. Randolph sees through the transparent scheme of being sick in Philadelphia and stealing his sweetheart's jewelry in New York. It is one thing to see the trick, however, and quite another to prove it. He thinks that Thauret and Fisher are both virtuous. Well, I am afraid he is mistaken there." He took up another letter. It read:

"Philadelphia, Jan. 2d.

"Dear Mr. Barnes:

"Pardon my familiarity, but I think we are getting pretty well acquainted with one another. I have just read the New York newspapers, and am startled to see that Miss Remsen was deliberately robbed of that valuable ruby pin which I recently gave her. You will remember that I showed you the gem the very day that I took it to be set. I am very much disturbed about this affair, especially as I am unable through sickness to return to New York, and my physician warns me that it will be several days before I can leave my room. Will you do me a great favor? Forget that I ever disparaged the detective force of which you are undoubtedly a brilliant member, and take this case in hand. I will give you one thousand dollars if you will recover the jewel, which is only a small reward considering its value. I send you a check for two hundred dollars, which you may use for expenses, and if more be needed let me know. I wish you could run over to Philadelphia to see me. A conversation with you would be a great satisfaction to me. Will you oblige,

Yours very truly,
"Robert Leroy Mitchel."

Mr. Barnes read this no less than three times, and then said aloud, though there was no one to hear him: "Well!" That was all, but the tone was rich in suggestiveness. What he thought, but did not put into words, was: "That man has the coolest audacity I ever met. Here he actually offers me a thousand dollars to recover that ruby, when he knows that I was right by his side at the time of the theft. Is he so egotistic that he dares to guy me? Is he so sure that he cannot be convicted? I know that he was not in Philadelphia any way, as my man found his room empty. His alibi is broken, at all events, clever as he thinks himself. Will I go to Philadelphia to see him? Well, I should think so! A conversation with him will be as satisfactory to me as it possibly can be to him. But first I must obey the call from Miss Remsen. There may be much to learn there."

It was nearly an hour before Mr. Barnes's duties in connection with other cases made him at liberty. He went straight to Miss Remsen's, and was shown into her presence.

"You sent for me, Miss Remsen," he began.

"Yes, Mr. Barnes," she replied. "Will you be seated?" The detective accepted her invitation, and she continued: "To come to the point at once, I wish to see you about my lost ruby. It was a present from Mr. Mitchel to me, and besides being very costly, I attach a sentimental value to it. I want you to undertake to recover it, and I will give you a thousand dollars if you succeed."

Mr. Barnes had never had so many thousand-dollar offers made to him in so short a time before. He smiled slightly, and said:

"Your offer comes too late, Miss Remsen. I have a letter from Mr. Mitchel himself, making a similar offer. It would scarcely be proper for me to accept two rewards for one service."

"Then you refuse to help me?"

"On the contrary, I will use my utmost endeavors to detect the thief and recover your property for you. But I need no money from you."

"You are very conscientious, Mr. Barnes, and I admire it. I honor a man who places his duty above money."

"I thank you for your courteous remark. Now, if I am to help you, you must begin by assisting me."

"I will do whatever I can, certainly."

"Then tell me, have you no suspicion as to who might have taken your jewel?" The girl hesitated, and the detective watched her face keenly. As she did not reply at once, he asked another question.

"Did you feel the person take the pin from your hair?"

"Yes, I did, but I did not realize what was occurring till he had it!"

"Why did you not make any resistance, or cry out?"

Again she hesitated, but in a moment she said firmly:

"I know that you have a right to ask me these questions, and I will reply to them if you insist upon it. But first tell me, would it be right for me to call a name to you, as one that I may have suspected, when I had but the flimsiest excuse for my suspicion? Might I not thus do more harm than good by attracting your attention to a false scent?"

"That is certainly a possibility, Miss Remsen, but it is one which I am inclined to risk. I mean that I prefer to trust to my experience, than to have you omit to tell me your suspicions."

"Very well, only promise me that you will not jump to conclusions, and thus perhaps annoy the person whom I shall name."

"I agree to that. I will take no action without sufficient reason other than that furnished by yourself."

"Very well. You asked if I suspected any one, and again why I did not resist the thief. If you will remember, my head was bowed. At first I could not understand how something seemed to move my pin. I fancied that it had become entangled in the Sultan's robe. Then the clock began to chime, and in a moment it flashed across my mind that perhaps Mr. Mitchel was taking my pin, in order to win his wager. Therefore I said nothing. This makes my action clear to you?"

"Perfectly. Then I am to understand that Mr. Mitchel did not tell you in advance that he would do this?"

"No, he did not, and that is why I have sent for you."

"I don't understand you."

"Why, all the time that I thought he had the pin I was not worried. I even went so far as to act indignation at the festival. That was partly for your edification and mystification. I wanted to help Mr. Mitchel's plan. But when it occurred to me yesterday that Mr. Mitchel, if he had meant to take the pin, would have told me in advance, I saw at once that my first idea was wrong, and that my ruby is really gone. Then I wrote to you."

"Then you feel sure that he would have told you in advance?"

"Positive."

"May he not have feared to ask you to implicate yourself in a robbery, and possible scandal? You know he was liable to arrest, and it might be a considerable time before he could have proven that his theft was only a joke. He may have wished to spare you notoriety."

"He knows me better than that." She said this with a smile.

"How better?" asked the detective.

"I mean that he knows there is nothing that I would not risk for him, since I have consented to give him myself. I am one of those women, Mr. Barnes, who are not easily deterred from aiding the man of her choice."

"Do you mean that you would be willing to share unenviable notoriety with him, and that he knew this?"

"I do, and therefore feel confident that he would have asked my assistance if it had been his intention to take my pin."

"Just as he did on another occasion?" The detective had been leading her up to this for the last few moments, and now watched to see the effect. She did not change countenance, but simply said:

"What occasion?"

"The morning when he locked your maid in this room, whilst you went down-town and took a little girl from one house to another?"

"To what other?" This was a hard one for the detective, and as he did not reply she smiled aggravatingly, as she continued:

"Mr. Barnes, you have no proof of your assertion. You suspect that I did what you say, but you do not know it. As I told you just now, it is possible for a bare suspicion to lead one astray."

"Perhaps, but I do not think that I am far wrong in this instance."

"We will not discuss it. Let us return to the ruby. You told Mr. Van Rawlston, so he tells me, that you knew in advance that this crime was about to occur. Did you know the person who would take the pin?"

"To be perfectly frank with you, Miss Remsen, I expected that Mr. Mitchel would take it. I think now that he did take it. Do you wish me to continue the investigation? It may lead to your friend's losing his wager, whereas you have the right to notify the police that your gem has been returned to you. That would make our work on the case useless, and assure him of winning his bet."

Mr. Barnes's object here was ingenious. He thought that if the girl accepted his suggestion, he would thus be assured that she still suspected Mr. Mitchel. Thus he would reach her true opinion of the case. Her answer was.

"I cannot do that. It would certainly be to give up my hope of recovering the stone. I am sure that Mr. Mitchel has not taken it. If I am wrong, and he has done so without trusting me, why then he has made a mistake, and must suffer by it. I am sure, however, it will prove otherwise. So do the best you can, if you please."

"You may rely upon it that my best energies shall be devoted to this work. I wish you good-morning."

About six o'clock that same afternoon, Mr. Barnes sent his card up to Mr. Mitchel, at the Lafayette, in Philadelphia. A few minutes later he was shown into that gentleman's room, and found him in bed.

"Delighted to see you, Mr. Barnes. You are very kind to come and see me. For doing so, I am almost willing to forgive you for the wrong which you have done me."

"Wrong? What wrong?"

"Do you remember the day you came to see me at the Fifth Avenue, about the button which you had found? You asked me to show you the seventh of my own set. I agreed on condition that you would not annoy the lady."

"Well!"

"You broke your promise – that is all."

"In what way?"

"In the first place you bribed her maid to tell her a lie, and leave her, so that one of your spies could take her place. Secondly, your spy did take her place. The result of which was that Miss Remsen could not re-engage her old maid, and has had much trouble to get another as good."

"I did not foresee, when I made that promise, that such an emergency would arise as did later."

"Very true! But I did, and I warned you that you would gain nothing by making the promise, since you would only find my own story verified by your visit."

"Well, I am very sorry, and will say that it shall not occur again."

"But, Mr. Barnes, it has occurred again."

"How so?"

"Why, she cannot leave her home at any time, without being dogged by your spies."

Mr. Barnes bit his lip in chagrin to find how well this man was acquainted with his plans, but he replied unhesitatingly,

"This time you are wrong. I promised you not to annoy Miss Remsen in connection with the particular case of which we were then speaking. My men have shadowed her in connection with another affair."

"What other affair?"

"Abduction."

"Abduction? Absurd! Who on earth has Miss Remsen abducted?"

"The girl Rose Mitchel."

"And who, pray, is the girl Rose Mitchel? The daughter of the murdered woman?"

"Perhaps. That is what I intend to discover. She passed however, as your daughter."

"Ah! Now can you prove that she is not?"

"No."

"Very good. Then, so far as your information goes, Rose Mitchel who passed as my daughter, was removed from a certain house, to a certain other house, to you unknown." He paused a moment as though to enjoy Mr. Barnes's discomfiture, then continued: "She was taken, so you suspect, but cannot prove, by Miss Remsen. Now, then, if Miss Remsen, my affianced wife, takes a girl who is my own child from one house to another, where is the abduction so long as I make no complaint?"

"Let us drop this nonsense, Mr. Mitchel. You know very well that that child was removed for a purpose, else she would not be hidden away. If Miss Remsen had a hand in this, she was aiding you to baffle detective investigation, and that was an illegal act. Therefore we have the right to watch her, in order to discover what we can."

"Very well, then we will grant you that privilege. Much good may it do you. But as to the removal of the child, that was done because your spy Lucette had discovered where she was, and I did not choose to have her annoyed."

"What makes you so certain that this Lucette was my spy, as you term it?"

"Well, I don't mind telling you that, though perhaps I am showing my hand a little. Let us go to the beginning. In the first place you knew about my bet, and I knew that you knew that much. From that starting-point what more natural than for me to suppose that you would begin by having me shadowed. To be sure of this, I made a few trips on the elevated road, a structure peculiarly applicable for such a test, with the result of course that I soon became pretty well acquainted with your assistant. Whenever I had nothing else to do, I would amuse myself getting away from him. You gave me occupation for several hours I assure you. But to come to Lucette. I guessed that the next step in your game would be to supply spy number two, who would take up the trail wherever spy number one would lose it. I began to look for this second man. See, I admit that I did not count upon a woman. You beat me there, or almost did. I don't suppose you told the girl to let me see her face, eh?" Mr. Barnes made no reply, though to himself he said, "Just as I told the fool." Mr. Mitchel went on: "At last one day, just as I was getting on a train, a smart-looking young woman came out of the waiting-room and followed me aboard. Purely from habit I walked through the train to the first coach. I ride in that because it is the coolest in summer and the least draughty in winter. Now there were several cross seats empty in the coaches through which I passed, and as the young woman behind me did not take one, but followed me through the train, I became suspicious. When she sat down opposite to me, of course I studied her face. I hardly ever forget a face after I have made a mental note of it. The rest was simple. She was sharp enough not to get off the train when I did, and I dismissed her from my mind. Thus I suppose she was enabled to follow me to the Irving Place house. But of course I recognized her at once when I saw her at Miss Remsen's."

"Did I understand you to say that this Rose Mitchel is your daughter?"

"I don't know what you understood, but I did not say so. I spoke of her just as you did, 'Rose Mitchel, who passed as my daughter.'"

"Well, then, is she your daughter?"

"I decline to answer."

"Why do you do so?"

"I must decline to reply to that also."

"Do you not see, Mr. Mitchel, you are simply making your actions more and more suspicious?"

"My dear Mr. Barnes, I do not care a straw how much suspicion I arouse, so long as I am not confronted by any proof. Whenever you think you have any proof against me, come to me and I will endeavor to refute it."

"Very well. You have asked me to discover who stole Miss Remsen's ruby. I have already done so."

"Mr. Barnes, you are a genius. Who is it?"

"Yourself."

"Bosh! Can't you do better than that? Why, I have been sick abed here for over three days."

"Mr. Mitchel, you are caught this time. You were not sick abed here at the time of the robbery. On the contrary you went over to New York, attended the festival, and took the ruby pin from Miss Remsen's hair."

"Mr. Barnes, you are laboring under a delusion. I tell you I have been in this room since December 30th."

"One of my men followed you to this place. On the night of the 1st, he registered at this hotel, being assigned to the room next to this. He picked the lock of the communicating door, and came in here, thus discovering your absence."

"Very clever idea, I am sure. The fellow deserves credit. But did he tell you which communicating door he came through?"

Mr. Barnes looked around and was amazed to find that the only door in the room opened on the hall. The story told by his man was thus an impossibility. A thought came to him quickly and he said:

"You have changed to another room since then. You were at that time in No. 234."

"And this is number 342, a floor higher up. But you are wrong; I have not changed my room. I will explain how your man has made this mistake. I knew when I came here that your spy had probably followed me. I was tired of the espionage. This is what I did. I registered and was given number 234. I was shown to the room and at once sent for the clerk. When he came up I asked for another room, and desired him not to make any change on the register, as I had an inquisitive friend who would not hesitate to walk right up if he knew what room I was in. I explained that I wished to avoid him. My request was granted. I suppose your man asked for a room near that of his "friend Mr. Mitchel." The clerk at once thought him to be the man whom I wished to avoid, and gave him a room next to 234, which of course satisfied him, and I am sure pleased me as well."

Mr. Barnes was supremely disgusted, especially as, during the interview, he had become thoroughly satisfied that Mr. Mitchel was really sick and troubled with a bad cough. He returned to New York puzzled.

CHAPTER XII.
THE HISTORY OF THE RUBY

During the next two weeks there were numerous references to the ruby robbery in the daily papers. Interviews were published purporting to have been held with every one of note who had been present. The police were twitted with their inability to discover the thief. The detectives from the central office came and went mysteriously, and were silent to all questioners, the while maintaining an expression which plainly said, "We could an' if we would." One or two persons were even arrested, only to be promptly discharged when brought before the committing magistrates. So that interest in the affair soon died out. Another crime occurred, and all New York had something else to talk of. The Remsen ruby was forgotten by the masses.

Mr. Barnes, however, thought of little else. He racked his brain for a promising starting-point, and the more he thought, the more he was tempted to make a trip to New Orleans, to unravel this, as he had many other mysteries, "from the other end." Yet he hated to leave the scene where were the chief actors in the drama, and, as he felt certain, the principal in one or all of the crimes. At last he resolved to make a move, hoping little from it, yet unwilling longer to rest actually idle in this case. He wrote the following letter:

"Mr. Arthur Randolph:

"Dear Sir – Since you have engaged me to undertake to prove that Mr. Mitchel himself stole the ruby on the night of the festival, I presume that you will consent to give me some assistance in the matter. In the first interview that I had with you you may recall that you stated that your friend, in your opinion, is somewhat insane on the subject of celebrated jewels. You said, in effect, that if he were pressed a little on this line he would drift off into the narration of tales of gems and crimes committed to obtain them. I would much like to hear Mr. Mitchel talk upon his hobby, but, as you know, he is on the defensive with me. Can you in some way arrange to have a talk with him yourself and draw him out, whilst I should be secreted where I could overhear the conversation? I should wish you to mention the loss of the ruby, to suggest, if not charge outright, that he himself has taken the gem; and when he denies it, as he surely will, ask him whether there is any peculiar story connected with it – that is, whether it has ever been stolen before. From such a conversation I might get a hint, which, seeming as nothing to you, might be valuable to me. Will you do this? Remember you yourself said that 'all is fair,' etc.

Yours truly,
"J. Barnes."

In reply to this he received a note asking him to meet Mr. Randolph at his club on the following evening.

The next afternoon Mr. Mitchel called at the Hoffman House and went up to the room occupied by Mr. Thauret, finding that gentleman at home. Mr. Thauret advanced to meet him, and the two shook hands cordially.

"Thauret," began Mr. Mitchel, "I want to talk to you seriously about that jewel robbery."

"I am all attention," said Mr. Thauret, lighting a cigarette and dropping into a comfortable rocking-chair.

"To begin with, let me recapitulate. I will go back to our partnership arrangement. You and I became, in a way, secret partners, or, perhaps, 'gambling pals' would be more accurate. At that time I agreed to furnish the capital for our operations up to a certain point. I believe I have done so, in spite of the fact that our losses have been rather heavy, and the further fact that you confidentially told me that you had a method, or a system, by which losses could be avoided, or at least controlled. Am I accurate?"

"Quite so, my friend. You have proven yourself an admirable silent partner, since you have allowed me to have my own way, paying the bills and asking no questions, till now. Am I to understand that the losses annoy you, and that you wish an explanation?"

"You may give me one in a moment. There is another point. You promised to drop Adrian Fisher."

"Well?"

"You have not done so. I requested you to wear the Ali Baba costume the other night, and yet you chose to give it to Fisher. Why was that?"

"It will be more simple to explain about the losses first, and come to Fisher later. As you perhaps know, that detective Barnes has chosen to place a spy at my heels. Under the circumstances, I thought it wise to play the spy upon my spy. Several times I have gone to the club, and then placed myself where I could watch my man. In this way I soon discovered that he had become intimate with one of the club servants. One day I called this fellow, and partly by threatening to have him discharged, but mainly by using money, I got out of him what the detective was asking about me. This was chiefly whether I lose or win when I play cards. I found that the result of every game that I played was being reported. Consequently after that I made it a rule to lose."

"To lose my money!"

"To lose our money, since we are partners. You are simply advancing the funds till I get remittances from Paris. You have my I.O.U.'s. If you are tired of the arrangement, I will pay you at once, though it would be inconvenient."

"No, the money is of no consequence. But tell me, why did you think it best to lose?"

"It is very simple. From the fact that the detectives are investigating this point, it is evident that they had heard of the winnings which I made when Fisher played with me. They may have concluded that I am a card sharper. I wish to dispel that idea."

"Naturally. But now tell me about Fisher. What has this to do with him?"

"As you know, I did not design to attend the festival. You went to Philadelphia, were taken ill, and sent me a letter asking me to take your place, and wear your dress, which I was to obtain by presenting your note to the costumer. I did this, fully intending to carry out your wishes."

"Then how was it that Fisher wore my costume?"

"I am coming to that. Just before leaving for the affair, who should call here but the costumer, who informed me that a man had been to his place, and had catechised him about me, explaining that he was a detective hunting down a celebrated criminal. He showed the fellow your note. Afterwards he regretted having done so, and came to notify me, as he expressed it, 'so that I might not get into any trouble.' I saw at once that this meant that Barnes would be at the festival, or, at any rate, one of his men."

"You were right in that. He was there."

"Yes, but I was not sure of it till after the robbery, when all unmasked. He wore one of the Forty Thieves dominos, and I failed to see through the disguise. With the knowledge thus obtained, I determined to have some amusement at the expense of your great detective, and decided to wear one of the dominos instead of your dress. It was essential, however, that some one should impersonate Ali Baba in order that the tableaux might not be interrupted. Fisher was the only man I could ask to assume the rôle. He acquiesced, and that is all there was to that. I have not taken him up again, I assure you."

"Very good. That is satisfactory. You must pardon my questioning; but after all, I did not understand, and had a right to do so. Tell me, were you near when the robbery occurred? Did you see it done?"

"I must have been near, but I did not see it. I was awaiting to kiss the hand of the Scheherezade when Mr. Barnes suddenly cried out that a robbery had been committed, and ordered masks off. I slipped out of my domino, and went to him as soon as the lights were on."

"You might have suggested to him to search everybody, as he did on the train."

"By George! that is just what I did, but he declined. I guess that train experience made him dubious as to the value of that sort of thing."

At this both men laughed heartily, as though enjoying the discomfiture of the detective.

"It seems," said Mr. Mitchel, "that Barnes suspected that the ruby was to be stolen, and informed Mr. Rawlston early in the evening that there would be thieves in the audience."

"Did he, indeed? Too bad that, with all his shrewdness, he was not able to catch the thief, or thieves rather, eh?"

Once more they both laughed. Then Mr. Mitchel suggested that they should go to the club, and thither they went. Upon entering, the doorkeeper informed Mr. Mitchel that Mr. Randolph was in the parlor and desired to see him. He and Mr. Thauret therefore went into the great reception-room. Mr. Randolph arose as they appeared.

"Good-evening, Randolph," said Mr. Mitchel. "You wish to see me?"

"Oh, nothing special. I came in to dine here, and told the doorman to send you to me in case you should turn up. I wanted company, that is all."

"Don't like to eat alone, eh?"

"That is it. Eating is a nuisance, made tolerable only by good companionship. Mr. Thauret, shall I have a place set for you, also?"

"If you desire, I shall be most happy," said Mr. Thauret.

"Very well," said Mr. Randolph. "I will attend to it. I have some letters to write now, if you will excuse me. Meet me promptly at seven in the private dining-room."

Mr. Randolph left the apartment, and went to the floor above. Here he joined Mr. Barnes, who was awaiting him.

"Well," said the detective, "can you manage it?"

"Everything is arranged. Mitchel is here, and he has brought Thauret with him. I don't understand the intimacy that has sprung up between those two, but that is not to the point. They will dine with me in our private dining-room. I shall arrange that our meal shall be served at a table immediately next to the large portière that separates the private dining-room from the main saloon. I shall also order a dinner for you at a table just on the other side of the curtain. If you have good ears, you should hear all that passes with little difficulty."

"I am satisfied with your arrangement and shall undoubtedly be able to hear at least the greater part of what occurs."

"Very well. Now go to the library, and at the farther end, hidden behind a newspaper file, you will be safe from the observation of prying eyes. Promptly at seven, I and my guests will take our seats. Five minutes later your own place will be in readiness, and you can take it in safety."

Mr. Barnes followed these instructions, and Mr. Randolph went to the dining-room to perfect his arrangements. At seven, on the minute, he was joined by his invited guests, and the three sat at table. Shortly after the noise of dishes on the other side of the portière indicated that Mr. Barnes was being served.

About the third course Mr. Randolph endeavored to lead the conversation in the desired direction.

"I trust," said he, addressing Mitchel, "that you have entirely recovered from that unfortunate illness that prevented you from attending the affair at Rawlston's."

"Oh, yes," said Mitchel, "it was but a temporary matter. The only serious result was that I was kept from the festival. I think I might have saved Miss Remsen from the annoyance of losing her ruby."