Fred’s letter was a great relief to me. I had not dared to allow my thoughts to dwell on the man whom I had seen in May Derwent’s apartment on that eventful night. The supposition, however, that it was her brother, explained everything satisfactorily. Nothing could be more likely than that this angel of mercy should give shelter to this returned prodigal, and try to save him from the punishment he so richly deserved. But what cared I what he had done? She—she—was immaculate.

At the hospital that morning, I was in such good spirits that I had some difficulty in keeping my elation within bounds. As it was, I noticed that several nurses eyed me with suspicion.

My preoccupation about Miss Derwent’s affairs had been so great that I had hardly given a thought to the mysterious murder, and was consequently very much surprised, on returning home that afternoon, to find the detective patiently awaiting me.

“Well, Mr. Merritt,” I exclaimed; “glad to see you; what can I do for you? Anything wrong with your heart, or your liver, or your nerves, eh?”

“Well, Doctor, I guess my nerves are pretty near all right,” he answered, with a slow smile.

“I’m glad to hear it. Won’t you sit down?”

He selected a comfortable chair, and we sat down facing each other. I wondered what could be coming next.

“Now, Doctor,” he began, in a matter-of-fact voice, “I’d like you to tell me all you know of the murder.”

He had taken me completely by surprise, but I am learning to control my features, and flatter myself that I did not move a muscle as I quietly replied:

“This is a very strange question, and I can only answer that I know nothing.”

“Oh, hardly as little as that,” the detective rejoined, with irritating complacency.

“Just as little as that,” I asserted, with some warmth.

“Well, Doctor, if that is the case, you can no doubt explain a few things that have been puzzling me. In the first place, will you tell me why, if you were not expecting another victim, you showed such surprise at the sight of the corpse? What reason could you have had for being so deeply interested in the relative positions of your roof—not your office, mind you, but your roof—and the room in which the body was found, unless you had noticed something unusual from that point of observation? Why were you so sure that the Derwent’s flat was occupied, if you had not seen some person or persons there? By the way, I noticed that from your roof I could look directly into their windows. Again, you betrayed great surprise when Miss Derwent lifted her veil. Why did you do so, except that you had previously seen a very different looking person in her apartment? And why did you select the Atkins’s two servants out of all the people in the building, to question about a certain noise, but that you yourself had heard a scream coming from their premises? And, lastly, you showed an unexplained interest in the back door of the Rosemere, which is particularly suggestive in view of the fact that this window is exactly opposite to it. I need only add that your presence on the roof during some part of Wednesday night, or early Thursday morning, is attested by the fact that I found some pipe-ash near the chimney. You smoke a pipe, I see” (pointing to a rack full of them); “your janitor does not, neither do your two fellow-lodgers. Besides that, all the other occupants of this house are willing to swear that they have not been on the roof recently, and those ashes could not have been long where I found them; the wind would have scattered them. You see, I know very little, but I know enough to be sure that you know more.”

I was perfectly dumbfounded, and gazed at the detective for some moments without speaking.

“Well, granted that I was on the roof during a part of Wednesday night, what of it? And if I did hear or see anything suspicious, how can you prove it, and above all, how can you make me tell you of it?”

“I can’t,” rejoined Mr. Merritt, cheerfully. “I can only ask you to do so.”

“And if I refuse?”

“Then I shall have to delay satisfying my curiosity till we meet in court, but I do not doubt that my patience will then be adequately rewarded, for a skilful lawyer will surely be able to get at many details that would escape me, and I hardly think that you would resort to perjury to shield two women whom I am convinced you never laid eyes on before yesterday, and have certainly not seen since.” The detective paused.

I still hesitated, for I felt an extreme reluctance to further compromise that poor girl by anything I might say.

“Come, Doctor,” he urged, leaning forward and placing his hand on my knee, “don’t you think it would be better for all parties for you to tell me what you know? I am as anxious to shield the innocent as you can be. By withholding valuable information you may force me to put a young lady through a very trying and public ordeal, which I am sure might be easily spared her, if I only knew a few more facts of the case.”

This last argument decided me, and making a virtue of necessity I gave him a minute account of all I had seen and heard. When I came to describing the man’s prolonged search Mr. Merritt nodded several times with great satisfaction.

“Can’t you tell me a little more how this man looked?” he eagerly inquired. “You must have seen him pretty clearly while he was moving around that lighted room. Had he any hair on his face?”

“Well,” I confessed, “it is a funny thing, but I can’t for the life of me remember; I’ve tried to; sometimes I think he was clean shaven, and again I am sure he had a small moustache.”

The detective glared at me for a moment; it was difficult for him to forgive such aggravating lack of memory. To be given such an opportunity and to foozel it! He heaved a sigh of resignation as he inquired:

“Can you remember how he was dressed?”

“Oh, yes,” I replied with alacrity, anxious to retrieve myself, “he had on a white shirt and dark trousers, and his sleeves were rolled back.”

“Did he close the windows before he left?”

“Yes, and he pulled down the blinds also.”

“You are sure that you saw no one in the apartment resembling Miss Derwent?”

“Quite sure; the woman I saw was taller and had flat, black hair.”

“What do you mean by ‘flat’?”

“Why, nowadays girls wear their hair loose; it bulges away from their faces; but hers lay tight to her head in a flat, black mass,” I explained.

I then harped on the probability of the return of Miss May’s prodigal brother, and suggested the possibility that the dark-haired woman might be his wife.

“Well, well, Doctor! This is all very interesting. The story of the brother, especially. You see, I had already discovered that a man had spent many hours in her apartment——”

“How did you find that out?” I interrupted.

“Oh, quite easily,” rejoined the detective; “as soon as all the excitement was over yesterday, I made McGorry open the Derwent’s apartments for me. You may imagine what a fuss he made about it. Well anyhow he got me——”

“But why did you want to get in?” I inquired; “did you suspect her?”

“No,” he replied, “I did not. But in my profession you take no chances. Impressions, intuitions, are often of great value, only you must be careful always to verify them. I was almost sure that the young lady was innocent, but it was my business to prove her so. Now, it is certain that the person, or persons, who smuggled the corpse into the room where it was found, must, at one time or another, have had the key of that apartment in their possession, and there are only three people whom we know of as yet who were in a position to have had it. These three are: Miss Derwent, the French butler, and, of course, McGorry. So far I have not been able to connect the latter two, even in the most indirect way, with the catastrophe. Unfortunately, that is not the case with the young lady. One person, at least, has identified the body as that of her visitor, and your behaviour,” he added, with a smile, “led me to believe that you suspected her of something. Not of the crime, I felt sure of that, but of what, then? I determined to find out, and now that I have done so, let me tell you that I am still convinced of her innocence.”

I jumped up and shook him by the hand. “So am I, so am I,” I exclaimed.

“But this is a very queer case,” he continued, “and I shall need all the assistance you can give me, if——”

“You shall have it,” I broke in, enthusiastically; “anything I can do. But tell me, first, how you found out about Miss Derwent’s brother?”

“Not so fast, young man! At present, we know nothing about a brother. I only said that I had discovered in the apartment traces of the recent and prolonged presence of a man, and I may add of a man of some means.”

“How did you find that out? Especially about his means?” I inquired, with a smile.

“Quite easily. In the parlor, which was the first room I entered, I noticed that every piece of furniture had been lately moved from its place. Now, this was too heavy a job for a girl to have undertaken single-handed. Who helped her, I wondered? Her visitor of Tuesday evening might have been the person, but for various reasons I was inclined to doubt it. I thought it more likely to have been the woman whose existence your behaviour had led me to infer. I next examined the dining-room. A few crumbs showed that it had been used, but I could find no traces of her mysterious companion. The library had not even been entered. On the floor above, the front bedroom alone showed signs of recent occupation. Two crumpled sheets were still on the bed, and in the drawers were several articles of woman’s apparel. Returning to the lower floor by the back stairs, I found myself in the kitchen. Here, in the most unexpected place, I discovered an important clue.” Mr. Merritt paused, and looked at me with a gleam of triumph in his eye.

“Yes, yes, and what was that?” I inquired, breathlessly.

“Only the odor, the very faintest ghost of an odor, I may say, of cigar-smoke.”

“In the kitchen?” I exclaimed, incredulously.

“In the kitchen,” repeated the detective. “I at once drew up the blinds, and looked out. The window opened directly on the fire escape, with nothing opposite but the roofs of some low houses. Pulling out my magnifying glass, I crawled out. I soon satisfied myself that the stairs leading up and down had not been recently used; on the other hand, I was equally sure that someone had very lately been out on the small landing. So I sat down there and looked about me. I could see nothing. At last, by peering through the bars of the iron flooring, I thought I could discern a small brown object, caught in between the slats of the landing below. I climbed down there mighty quick, I can tell you, and in a moment held the butt end of a cigar in my hand. It was, as I had suspected, from the delicate odor it had left behind, one which had cost about fifty cents. I now extended my search downward, and examined every window-sill, every crevice, till I reached the basement, and, as a result of my hunt, I collected five cigar stumps, all of the same brand. From the number, I concluded that whoever had been in the apartment had been there a considerable time. From his only smoking in the kitchen or on the fire-escape, I gathered that he was anxious to leave no traces of his presence; and lastly, from the quality of his cigars, I judged him to be a man of means. So you see I had discovered, even without your assistance, that, although Miss Derwent may have told us the truth, she certainly had not told us all of it.”

I nodded gloomily.

“What you tell me of this dark-haired woman is still more puzzling,” the detective continued. “She has covered up her tracks so well that not only did I find no trace of her, but no one, not even yourself, saw her either enter or leave the building. And I should never have dreamed of her existence if I had not noticed your surprise when Miss Derwent lifted her veil. Now, the first thing to be done is to try and find this strange couple, and we will begin by tracing the man whom you saw leaving the Rosemere with a market-basket. It will be easy enough to find out if he is nothing but a local tradesman, and if he is not, then in all probability he is the man we want. The detective who is watching Miss Derwent——”

“A detective watching Miss Derwent!” I exclaimed.

“Why, yes. What did you expect? I sent one down with her to the country yesterday.”

Perhaps I ought to have been prepared for it, but the idea of a common fellow dogging May Derwent’s footsteps, was quite a shock to me, so I inquired, with considerable ill-humor: “And what does he report?”

“Nothing much. The young lady returned to her mother, as she said she would, and since then has kept to her room, but has refused to see a doctor.”

“Have you discovered yet who the dead man really is?” I asked, after a slight pause.

“No,” answered the detective, with a troubled look, “and I can’t make it out. Jim and Joe each persists in his own identification. I expected Jim to weaken, he seemed so much less positive at first, but whether he has talked himself into the belief that the corpse is that of the young lady’s visitor, or whether it really does resemble him so much as to give the boy grounds for thinking so, I can’t make out.”

“I see, however, that you believe the murdered man to be Mrs. Atkins’s friend, of whose history and whereabouts she was so strangely ignorant.”

“Well, I don’t know,” the detective replied. “We have found out that an Allan Brown did engage a berth on the midnight train to Boston.”

“Really? Why, I was sure that Allan Brown was a creation of the little lady’s imagination. By the way, it is a strange coincidence that two mysterious Allans are connected with this case.”

“Yes, I have thought of that,” the detective murmured; “and Allan is no common name, either. But it is a still stranger circumstance that neither of Allan Brown nor of the murdered man (I am now taking for granted that they are not identical) can we discover the slightest trace beyond the solitary fact that an upper berth on the Boston train was bought on Tuesday afternoon, by a person giving the former’s name, and whose description applies, of course, equally to both. Mrs. Atkins volunteers the information that Brown was a stranger in the city, and so far I have no reason to doubt it. Now, a man who can afford to wear a dress suit, and who is a friend of a woman like Mrs. Atkins, presumably had fairly decent quarters while he was in town. And yet inquiries have been made at every hotel and boarding-house, from the cheapest to the most expensive, and not one of them knows anything of an Allan Brown, nor do they recognize his description as applying to any of their late guests. The deceased, of course, may have had rooms somewhere, or a flat, or even a house, in which case it will take longer to trace him; although even so, it is remarkable that after such wide publicity has been given to his description, no one has come forward and reported him as missing. The morgue has been crowded with idle sightseers, but nobody as yet claims to have seen the victim before.”

“That is queer,” I assented, “especially as the dead man was in all probability a person of some prominence. He certainly must have been rich. The pearl studs he wore were very fine.”

“Oh, those were imitation pearls,” said the detective, “and I am inclined to think that, far from being wealthy, he was, at the time of his death, extremely badly off, although other indications point to his having seen better days.”

“Really!” I exclaimed.

“Yes; didn’t you notice that his clothes, although evidently expensive, were all decidedly shabby? That his silk socks were almost worn out; that his pumps were down at the heel?”

“Yes, I did notice something of the kind.”

“But those large imitation pearls blinded you to everything else, I see,” Mr. Merritt remarked, with a smile.

“I suppose so,” I acknowledged; “they and the sleeve-links with the crest.”

“Ah, those are really interesting, and for the first time in my life I find myself wishing that we were more careful in this country about the use of such things. Unfortunately, we are so promiscuous and casual in adopting any coat-of-arms that happens to strike our fancy that the links become almost valueless as a clue. Still, I have sent one of them to an authority in heraldry, and shall be much interested to hear what he has to say about it. By the way, did anything else strike you as peculiar about the corpse?”

“No,” I answered, after a moment’s reflection.

“It did not seem to you odd that no hat was found with the body?”

“Dear me! I never noticed that. How singular! What could have become of it?”

“Ah, if we only knew that we should be in a fair way to solving this mystery. For I have found out that, whereas the description of Miss Derwent’s visitor and Mrs. Atkins’s friend tally on all other points, they differ radically on this one. The former wore a panama, whereas the latter wore an ordinary straw hat. Now, one of those hats must be somewhere in the Rosemere, and yet I can’t find it.”

“Mr. Merritt,” I inquired, “have you any theory as to the motive of this murder?”

“Not as yet,” he replied. “It may have been jealousy, revenge, or a desire to be rid of a dangerous enemy, and if you had not given it as your opinion that the man met his death while wholly or semi-unconscious, I should have added self-defence to my list of possibilities. The only thing I am pretty sure of is—that the motive was not robbery.”

“Look here, Mr. Merritt, I can’t help wondering that, whereas you have treated Miss Derwent with the utmost suspicion, have made a thorough search of her apartment, and have even sent a sleuth to watch her, yet you have shown such indifference to Mrs. Atkins’s movements. Surely suspicion points quite as strongly to her as to the young lady?”

“No, it doesn’t,” replied the detective. “The key! You forget the key cannot so far be connected with her. But, may I ask, who told you that I had neglected to make inquiries about the lady?”

“Nobody; I only inferred,” I stammered.

“You were wrong,” continued Mr. Merritt. “I have made every possible inquiry about Mrs. Atkins. I have even sent a man to Chicago to find out further particulars, although I have already collected a good deal of interesting information about the little lady’s past life.”

“Really? And was there anything peculiar about it?”

“No; I can’t exactly say there was. Mrs. Atkins is the only daughter of a wealthy saloon-keeper, John Day by name, and is twenty-six years old. Nothing is known against her except that in that city she chose her companions from amongst a very fast crowd. There is also a rumor, which the Chicago detective has not been able to verify, that when she was about sixteen or seventeen years old, she eloped with an Eastern man, from whom she was almost immediately divorced. At any rate, she has been known for a good many years as Miss Day, and has lived at home with her father. The memory of her marriage, if indeed she ever was married, has grown so dim that a great many people, among whom may be numbered some of her intimate friends, have never heard of it, and vehemently deny the whole story. I hope, however, soon to find out the facts of the case. Young Atkins met his wife last winter at Atlantic City, and at once fell in love with her. His father, who is a very wealthy contractor, was strongly opposed to the match. He was very ambitious for his son, and thought the daughter of a saloon-keeper, whose reputation was none of the best, was no desirable wife for his boy.”

“But they married in spite of him,” I said.

“Yes, and old man Atkins has become reconciled to them, and makes them a very handsome allowance.”

“How long have they been married?” I asked.

“Since the fifteenth of April,” replied the detective, “and they were not married in Chicago, but in this city. I guess the lady was not over anxious to introduce her husband to her former pals.”

“I suppose you have searched her apartment for a possible clue,—the hat, for instance?”

“Yes, but as she has not been out since Wednesday, I have not been able to make as thorough a search as I should like. She is a shy bird, and I don’t want to frighten her till I have a few more facts to go on. If she thinks herself watched she may become wary, while now, I hope she will make use of her fancied security to do something which may give us a lead.”

“Well, Mr. Merritt, I conclude from all this that, although you are unable to trace the possession of the key to Mrs. Atkins, nevertheless, your suspicions point towards her?”

“Certainly not. There is nothing to connect her with the tragedy, except the fact that one negro boy identified the corpse as that of one of her visitors. On the contrary, the more I look into this case, the less do I see how the lady could be involved in it. Let us suppose that she did kill the man. Where could she have secreted him during the twenty-four hours that must have elapsed before the body was finally disposed of? The only place of concealment on the lower floor of her apartment is a coat closet under the stairs, and I doubt very much whether a small, unmuscular woman like Mrs. Atkins is capable of dragging so large a man even for a short distance.”

“But,” I suggested, “the murder may have been committed in the hall, just a step from this hiding-place.”

“Yes, that is, of course, possible. But there is still another objection. The closet is so small that I do not believe a man could be got into it without doubling him up, and of that the body shows no signs. Besides, if Mrs. Atkins is guilty, we must believe her husband to be her accomplice, for who else could have helped her hide her victim? Now, you must know that the Atkins men, both father and son, bear most excellent reputations, especially the young man, of whom every one speaks in the highest terms, and I do not think that a person unaccustomed to deceit could have behaved with such perfect composure in the presence of a corpse of which he had criminal knowledge.”

“But he did show some emotion,” I urged.

“Oh, yes; I know what you mean,—when he learned that the man was murdered on Tuesday night he seemed startled.”

“Well, how do you account for that?”

“I don’t account for it. Why, Doctor, in a case like this there are a hundred things I can’t account for. For instance, what was the cause of Mrs. Atkins’s scream? You have no idea; neither have I. Why did she show such emotion at the sight of the corpse? I am not prepared to say. Why did she appear so relieved when she heard that the murder occurred on Tuesday? I can formulate no plausible explanation for it. And these are only a few of the rocks that I am running up against all the time.”

“But look here. If you really believe Miss Derwent and Mrs. Atkins both innocent, who do you think killed the man?”

“I don’t know. Oh, I am aware that the detective of fiction is always supposed to be omniscient, but my profession, Doctor, is just like any other. There is no hocus-pocus about it. To succeed in it requires, in the first place, accurate and most minute powers of observation, unlimited patience, the capacity for putting two and two together. Add to this an unprejudiced mind, and last, but not least, respect, amounting to reverence, for any established fact. Now, the only facts we have as yet gathered about this murder are: that the man was young, dissipated, and was stabbed through the heart by some very small instrument or weapon; that his assailant was an inmate of the Rosemere; that the crime was committed on Tuesday night; and, lastly, that whoever placed the body where it was found must, at one time or another, have had the key to the outside door in his or her possession. Whatever else we may think or believe, is purely speculative. We presume, for instance, that the man was poor. As for the other facts we have gleaned about the different inmates of the building, till we know which one of them had a hand in this tragedy, we cannot consider what we have learned about them as throwing any light on the murder. About that, as I said before, we know mighty little, and even that little is the result of thirty-eight hours’ work, not of one man alone, but of seven or eight.”

“Indeed!” I exclaimed.

“Now, both ladies deny that they knew the deceased, and perhaps they are right. It is, of course, possible that there was a third man in the building that evening, who was also tall, dark, and wore a pointed beard. It is not likely, however. Such a coincidence is almost unheard of. Still it is possible, and that possibility must be reckoned with. Now, I must be off,” said Mr. Merritt, rising abruptly from his chair, “and if you hear any more of the young lady’s movements, let me know. There’s my address. In the meantime, thank you very much for what you have already told me.” And before I could get out one of the twenty questions that were still burning on my lips, the man was gone.

For some minutes I sat quite still, too miserable to think connectedly. Alas! my fears had not been groundless. The poor girl was in even greater trouble than I had supposed. I believed the detective to be a decent chap, who would keep his mouth shut, but how dreadful to think that her reputation depended on the discretion of any man. Should it become known that she had received one young man alone in an empty apartment, while another was seen there at three o’clock in the morning, it would mean social death to her. Oh, for the right to offer her my protection, my services!

Of course, it was now absolutely necessary to trace the man who spent Tuesday evening with her, and to prove beyond doubt that he was still alive. I wished that this might be done without her knowledge, so as to spare her the shock of finding herself suspected of a crime.

Again I thought of Fred, and at once sent him a few lines, begging him to let me know whether he or his sister knew of any friend or admirer of Miss Derwent who resembled the enclosed description, and if either of them did know of such a person, please to telegraph me the man’s name, and, if possible, his address. While giving no reasons for my questions, I again enjoined the greatest secrecy.