It was close on eleven when the cab drew up before the door of Sidney’s lodging in York Street, St. James’s, and as luck would have it Sidney himself was standing on the doorstep, in the act of inserting his latch-key in the lock. Gimblet saw himself recognised as he sprang out of the taxi, and saw also a look of unmistakable pleasure in the recognition.

“This man is as innocent as I am,” he thought, as the young soldier greeted him.

“Come in, do,” Sidney said, “you’re the very man I wanted to see. I went to your flat this evening, but you’d just gone out, so the porter said. I am anxious to hear if you have any news of my aunt and Miss Turner.”

He led the way upstairs as he spoke, and ushered the detective into a sitting-room on the first floor, switching on the light as he did so.

Gimblet waited till the door was shut behind them, and then turned a grave face to his host.

“The news is very bad,” he said slowly, and waited a moment to give time for the significance of the words to sink in, and to prepare Sidney for what was to come.

“What has happened?” cried Sidney. “Are they hurt? Is Miss Turner——”

He stopped short, grasping the back of a chair.

“I don’t know what has happened to Miss Turner,” Gimblet said, “but I have terrible news of your poor aunt. Mrs. Vanderstein has been foully and cruelly murdered. I come now from the discovery of her dead body.”

“Murdered!” cried Sidney, “murdered! Who by? How? Where?” He sat down mechanically, and stared at Gimblet. “And Miss Turner? Have they killed her too?”

The detective repeated that at present he knew nothing of the younger lady.

“Good God!” said Sidney, “what a dreadful thing.”

Leaning his elbows on the table, he hid his face in his hands for a few minutes, and Gimblet sat silent opposite him, waiting till he should recover from the first shock of the news.

When Sidney raised his head again the face he disclosed was pale and drawn.

“Poor Aunt Ruth,” he said. “Poor thing, poor thing. To think that she should be dead. I can hardly realise it, you know. She has been killed for her jewels, I suppose, after all. The devils! You haven’t caught them, have you?” and, as Gimblet only shook his head: “How can such a thing be possible here in civilised London? And to think of that beastly old raven, Chark, going about croaking as he has been, and hinting that I’d killed her! To think of his being right after all! I don’t mean about my killing her,” he added, “but there it is, she’s dead; and I come into her money just in time to save me from ruin. I hate the thought of it!” He was talking to himself more than to his listener, and Gimblet let him talk. “I almost wish she had altered her will,” he went on, “it’s a beastly notion: her death being my profit, you know. And I suppose they’ll say I’ve murdered her all the more now?” He looked up interrogatively; then, as he received no answer, his expression changed and he started up, alert and wide awake once more. “I say,” said he, “do you think I did it, too?”

Gimblet hesitated a moment before answering.

“As a matter of fact,” he said at last, “I do not. I don’t think so for a moment. But that is merely my personal opinion and, to tell you the truth, I think it will be just as well if you can account for your movements since Monday to the satisfaction of more people than myself. I ought to suspect you—it’s my business to suspect every one—but, as I say, I don’t.”

“I daresay things do look rather black against me,” Sidney said; “it’s my fault for not having bothered to defend myself. You see, it seems so eccentric to me that anyone should think such a thing. It seems so impossible, and absurd, if you don’t mind my saying so. One forgets that other people don’t know what one is capable of as one does oneself, and it never struck me yesterday that you, or Sir Gregory either, might suspect me. I did go and see the editor of the worst of the newspapers, and explained things to him, and told him to let old Chark know he was wrong. You may have noticed he’s eaten his words in to-day’s paper. But I didn’t think it necessary to say anything to anyone else. You see, I’ve got what you call an alibi. I was in the country from Monday evening till yesterday morning. I met a pal almost on Aunt Ruth’s doorstep when she turned me out of the house, and he got me to go off with him down to his house near Ascot to play golf, and I was down there till Wednesday. I had only just come back, in fact, when I came to see you. I didn’t know about my aunt’s disappearance till I read it in the train coming up; my friend came up at the same time and stayed with me till I left him at your door. It’s waste of time suspecting me; I admit that it looks as if I ought to have murdered the poor dear, but in view of the facts that theory doesn’t hold water.”

“I’m very glad to hear what you say,” said Gimblet, “and I wish you’d told me before, though I never really thought you had any direct knowledge of the affair. Still, you must confess, Mr. Sidney, that you were not quite open with me: there was something which you knew, and which you kept to yourself when we talked about it.”

“I’m blessed if there was!” cried Sidney. “What was it?”

For answer Gimblet took Barbara’s telegraph form out of his notebook and handed it to the young man.

“You didn’t tell me you had received this telegram from Miss Turner,” he said, “not even though I quoted most of its contents to you by way of a hint.”

Sidney took the form, and stared at it for a moment.

“It is her writing,” he said at last. “I wonder what the deuce she meant.”

He, also, produced a folded paper from his pocket and pushed it across the table to the detective.

It was the message as he had received it.

“You will observe,” he said, “that there is no signature. How was I to know who it came from? As a matter of fact, I guessed, or at least thought it possible she had sent it, as no one else cares whether I go to blazes or not. But I’ve no idea whatever why she chose to think I should get some money or good news on Wednesday. I need hardly say that I didn’t. And I saw no reason to speak to you of what only concerns a young lady and myself. It can have no possible bearing on her disappearance, or that of my aunt.”

“You think not?” Gimblet looked at him oddly.

“How could it? I can’t imagine what connection there could be. But of course you’re the sort of fellow who can read the secret of dark mysteries in anything, from the Tower Bridge to a baked potato, aren’t you? So perhaps there’s some occult inference that I fail to draw. By the way, you’ve not told me much yet. How did you discover the murder, and where?”

“I found the poor lady’s body buried in a house in the north of London,” said Gimblet, “No.13 Scholefield Avenue. As to how I discovered it, it was by the help of two or three facts from which I was able to draw certain inferences.”

“I wish you would tell me all about it.”

“Well,” said Gimblet, “as Sir Gregory told you over the telephone this morning, I heard, as a result of the advertisement I gave you yesterday to have inserted in the papers, that the two ladies were seen by an actress on Monday night, standing under a board ‘To Let,’ before a detached house in some street on the way to Carolina Road. I was unable to find that street yesterday, and it was not until I could get hold of the cabman who had driven the actress that I ascertained that Scholefield Avenue was the only street he had passed through on Monday night which contains detached houses. I went there at once and found out that No.13 had recently been let, the board having been removed on Tuesday morning. I rang the bell, but no one came to the door, so after getting the name of the house agent from a neighbour I went to the office and interviewed the agent. From him I learnt that the house had only been let since Monday, and that the tenant was a man named West who had been ready to pay a high rent for immediate possession, and who gave out that he was a recluse, desiring nothing so much as solitude and privacy. The agent happened to have a spare key of No.13 Scholefield Avenue and he sent his clerk down with me to open the door.

“As soon as I got in I ran over the house with my servant, who as well as Sir Gregory had accompanied me, but there was no one to be seen in it, and so I proceeded to make a careful and searching examination. Not to weary you with details, I soon found a considerable number of small paste spangles, or imitation diamonds, such as are sewn on to the more elaborate and gorgeous kinds of ladies’ evening dresses. As I found several of these on the staircase between the hall and the drawing-room and a good many more in the drawing-room itself, but none in any other part of the house, I thought it was likely that, if they came off Mrs. Vanderstein’s gown, this was the only room she had visited. There was, of course, the possibility that they had fallen from the dress of some one who had been in the room before the place was let, but I set against this the improbability of the mistress of the house or her friends being rich people who would wear such expensively ornamented materials, and also the fact that your aunt’s maid in describing her toilette to me had spoken of it as ‘diamantÉe.’

“The next discovery was a most alarming one. On moving the sofa I saw beneath it a large stain in the carpet, which various indications assured me was the result of some acid that had been upset. From the nature of the damage I was pretty certain that it had been caused by sulphuric acid or vitriol. Now this is a strange thing to find traces of in a lady’s drawing-room, and when you find it in an empty house which a young and beautiful lady has been seen to enter, but which she has never been seen to leave, and when you further reflect that the disappearance of this lady appears to be complete, and on the fact that when last seen she was wearing a fortune in jewellery, one of two conclusions appears inevitable, unless you assume that all these facts are entirely unconnected and the result of pure coincidence. Assume them on the contrary to be related to each other, and you are led, as I say, to consider two possibilities. So I asked myself at once whether Mrs. Vanderstein had been decoyed to the house by some demented creature bent on assuaging a mad jealousy by throwing vitriol at her, or whether she had been induced to visit it to satisfy the still more fatal greed of a robber. And the more I looked at it, the more likely it seemed that the poor lady had been murdered for her jewels and that the vitriol was used to make the recognition of her body, if it should be discovered, a negligible danger. A few minutes later I came across a powder puff perfumed with the peculiar scent your aunt was in the habit of using—I daresay you know it—and this dispelled any doubts I still had as to her having been in the room.

“I still hoped against hope, however, that she might have left it alive, and I found some evidence downstairs which led me to think she had been locked in one of the lower rooms for a time; but if so it must have been before she was taken up to the drawing-room. In the library a pane of the window was broken, no doubt by some one trying to escape or attract attention, and obviously it had been done by a woman, as a man could have opened the window, which was so stiff as to require more than a woman’s strength. The broken glass had been carefully removed from the frame, so that, but for the draught, it might well have passed unnoticed.

“That it had been broken since the letting of the house was clear, since I found a dustpan full of broken glass, which would not have been left so by the landlord’s servants, or by the charwoman who cleaned up after their departure. The sight of that dustpan filled me with hopes that were doomed to disappointment. Nothing offers a better ground for the impression and retention of finger marks than a piece of shining metal, and I expected to find a whole collection on the tin surface of the pan. But to my astonishment and disgust I could not find a single one; and this strengthened my opinion that I had to deal with deliberate crime, and that of no ordinary stamp, for it was plain that not only had some one cleaned and polished the dustpan after using it, but that the person who had done so had worn gloves. And it was the same all over the house. Not a finger-print to be seen, except in the room with the broken pane, on the white painted door of which I found several distinct marks of fingers. What more likely than that the poor lady, finding herself locked into a strange room, should have broken the window and beaten on the door with her hands in a sudden panic? In the same cupboard as the dustpan was an old newspaper crumpled into a ball, which I found to contain a handful or so of what appeared to be garden mould, and I could not at first imagine why it should be there, though I can account for it now. I had by this time been all over the house and made the most thorough and exhaustive search, but the only other clue I could discover was a negative one.

“I must tell you that I had made sure that there was no article in the house belonging to the tenant, Mr. West, as he called himself; everything was accounted for in the inventory and belonged to Mr. Mill, the owner. It became clear to me that West must have taken the place for a definite purpose other than the usual one of living in it, and since I knew that it had been occupied on Monday evening, his object doubtless fulfilled itself then in a terrible manner and he probably fled from the scene of his crime the moment he had, to the best of his ability, removed all traces of it. In his haste he had left the little spangles which had scattered themselves in the wake of his victim; and, though he cleaned up the dustpan as if he feared it should tell tales in spite of the precautionary gloves, he seemed to have thought the broken glass could not betray him, or else, perhaps, he had no time to dispose of it. But, if he had left nothing behind him, it looked as if he had taken something away.

“The chairs and sofas in the drawing-room were provided with loose chintz covers, with one exception. There was a small sofa which stood opposite the door naked and unashamed, in all the hideousness of the original, ugly upholstery. Not only was the tapestry which covered it of a meretricious nineteenth-century design, quite out of keeping with the good taste displayed all over the house in the choice of pattern and decoration, but the legs and arms, which were very much in evidence, were made of brown varnished wood peculiarly objectionable in appearance. It seems to me in the last degree unlikely that in a room so full of beauty and quiet refinement this one thing should have been allowed to flaunt its vulgarity, and hold the eye of the visitor with an awful fascination. I felt convinced that West was responsible for its nakedness, and it was quite likely that he, a man doubtless devoid of any artistic sense, would imagine that the absence of that cover might pass unnoticed, as the tapestry resembled the chintzes in general colouring.”

“But why should he remove it? What could he want with a loose chintz sofa cover?” asked Sidney, as the detective paused.

“I asked myself these questions,” continued Gimblet, “and I saw that there were only two explanations which met all the facts. It might be that the chintz bore traces of his crime that at all costs must be destroyed; it might be, for instance, stained with blood. But in that case he would probably have tried to burn it; that would be a difficult job, and there was no sign of a fire having been lighted lately in any of the grates. No coal in the cellar and no firewood. He would have needed brushes and blacking to make all ship-shape again, and his grate cleaning would probably have been amateurish. Or he might have had a use for the chintz. It would be a handy thing to wrap a dead body in before carrying it out to the grave he would dig for it in the garden. For it seemed to me certain that after killing his victim he would have buried her in the garden. There was a toolshed at the end of it, and I hunted there for a spade that should show signs of recent use; but to my surprise there was no spade at all.

“By this time it was dark and late, and I returned to the house with the intention of deferring till to-morrow a search for the grave, which I felt sure of finding if it was there. I had little hope that the poor lady had escaped, but it was still quite possible that my theories were mistaken, and that even the signs of vitriol having been used were capable of some other interpretation; and I gladly admitted to myself that I had no actual proof of foul play. And then, just as I was on the point of knocking off for the night, an elusive memory that had been troubling me ever since I entered the house suddenly flashed clearly into conscious recollection, and I knew that I had made no mistake.

“When I opened the drawing-room door for the first time I had been aware of a faint odour, which I seemed to catch a whiff of as it passed me, so to speak, and to lose again immediately. During the second in which I perceived it, its name was on my tongue, but before I could utter it the smell was gone and with it my knowledge of what it was. I racked my brains to remember it without the least result; but, though I gave up the attempt and concentrated every effort on investigating what was apparent to my other senses, the thing bothered me, and I did not entirely forget it. As I stood in front of the house after my vain search for a spade, it suddenly flashed into my mind what it was that I had smelt: it was the never to be mistaken smell of chloroform.

“I was staring absently up at the balcony of the drawing-room when the knowledge came to me, and in an instant another light dawned on me with equal suddenness. There was a great box or stand for plants on the balcony, and the neighbour who had given me some information as to the tenant had remarked that the mistress of the house would be sad to see her flowers so neglected. Indeed, they were all faded and withered, and he had implied that it was for want of water. Now, the thought that leapt into my brain as swift and as illuminating as lightning was this one: Why should the flowers die for want of water when we have had constant rain for the last two days? Clearly it was not drought that they were suffering from. But how if the soidisant West, having cruelly murdered your unfortunate aunt, proceeded to uproot the flowers and to bury her, wrapped in the sofa cover, in the flower stand? It was quite large enough for such a purpose, and if he had then replanted the flowers it was probable enough that they would feel the effects of his attempt at gardening.

“I went up at once and put this theory to the test. I am very sorry to say that it proved to be correct in every detail.”

Gimblet ceased speaking, and Sidney, who had listened in sad silence, lifted his head, and asked a question.

“The vitriol? They had used it—as you thought?” His voice was hoarse, and his face stern and grim.

“Alas, yes.”

“Hanging is too good for such brutes; but I will never rest till they hang for it. Have you any idea who are the fiends who did this?”

“An idea? Say rather that I have a suspicion,” returned Gimblet. “Surely you can see the direction in which the circumstances point?”

“Unless it was the chauffeur,” said Sidney, “I can’t imagine who can have done it.”

“I don’t think there is anything in the theory that the chauffeur or any one of the servants had a hand in it. There are several things which make that idea hardly worth considering. But there is one person against whom things look very black. Do you mean to say you can’t see who it is?”

“No, I can’t,” repeated Sidney.

“Mr. Sidney,” said the detective slowly, “where do you suppose Miss Turner is?”

“I only wish I knew,” answered the young man; “it is horrible not to know. Where do you think she can possibly be? Tell me the truth, Mr. Gimblet: do you believe she is dead?” He spoke harshly, and with averted eyes.

“No,” said Gimblet, “I don’t think she is dead.”

Something in his tone made Sidney look up. Gimblet was looking at him with a strange expression, and as their eyes met he turned away uneasily. For a minute Sidney stared at him wonderingly, and then an incredulous enlightenment stole over him.

“You can’t mean,” he said slowly, “that you imagine she had any knowledge of the attack on my aunt?”

Gimblet was silent; and his silence was more eloquent than words.

“But it is impossible,” cried Sidney, “that anyone out of a lunatic asylum should think such a thing. You don’t know her, Mr. Gimblet, she is the sweetest, dearest girl. The most unselfish, the most devoted, the loyalest girl in the world! How can you hint at it? Oh, I know it is your business to suspect people, but you go too far! I cannot hear a word against her.”

Gimblet turned and faced him.

“Be reasonable, Mr. Sidney,” he said, “and accept it as a fact that the young lady will be suspected. If she is innocent it will be better to try and clear her than to refuse to hear what there is to be said as to her possible complicity. I understand your feelings, but you must see that there is nothing to gain by disguising the truth. It is because I thought it possible that you might feel a keen interest in Miss Turner that I have told you I suspect her. I hope you may be able to help me to convince myself of her innocence, and surely the best way to do that is to try and get at the truth.”

“I will try and be reasonable, as you call it,” said Sidney, after a pause, “and I suppose by that you mean listening to your abominable accusations. Well, let’s hear your evidence, and if I can prevent myself from throttling you I will! More than that no man could say,” he added, with an attempt at a smile. “And I feel a beast even to allow you to speak of the thing.”

“I am extremely sorry to have to do it,” said Gimblet, “but no good ever came of shutting one’s eyes to facts, and it’s facts that make me suspect Miss Turner. In the first place, there is the fact that she stands to profit by Mrs. Vanderstein’s death to the tune of £30,000.”

“That applies to me, too, only more so,” interrupted Sidney.

“Yes, and I don’t think it of much importance,” admitted the detective. “I mention it as one of the points which is outside the region of speculation, and therefore not negligible. The second fact is that you were at your wits’ end for money.”

“I daresay! But what that’s got to do with your suspecting Miss Turner beats me,” cried Sidney.

“It’s got this to do, though I’m afraid you will not like my alluding to your most private affairs—Miss Turner is in love with you. We may call that fact No.3.”

“There is absolutely no foundation for that statement,” said Sidney, flushing hotly, while he could not but be conscious of a strange acceleration in the beating of his heart.

“Is there not?” asked Gimblet, looking at him thoughtfully. “Well, we will waive that point if you like. Let us say that Miss Turner has an unusually friendly feeling for you. So friendly that she would go to any length to provide you with the necessary funds. You yourself have as good as told me so much. You cannot deny that she was the person who urged you to try to get the money by false pretences.”

“I am sure she did not look at it in that light,” protested Sidney, while inwardly he cursed himself for the slip by which, on the previous day, he had allowed the sex of his friend to escape him.

“I saw you with her in the Park last Sunday, did I not?” said the detective; “I noticed her expression. I am rather an observant fellow in my way, you know. I have only seen that look on the faces of people very much in love. I find I must go back to that, after all, in spite of your objection to the suggestion.”

“I do object very much. Miss Turner has no such feelings for me, I am sure, and I can’t let you impute them to her.”

“I am afraid you must,” said Gimblet tranquilly. “People who are madly in love,” he continued, “as I believe her to be, are capable of any sacrifice, of any heroism, or of any villainy. In that state of exaltation they are apt to lose their sense of proportion, and to confound extremes; they may see in the basest depths of infamy only another aspect of noble heights of self-abnegation; if the object of their affections is in danger, they may consider no expedient too shameful if it can be made to provide a means of extricating him.

“There is nothing inherently impossible in imagining that Miss Turner, conscious of nothing but your need, blindly strove to supply it and was in no mood to boggle at any feasible method. I don’t know if you are aware of the character borne by her father. He was a man of the worst reputation: an utterly merciless and unscrupulous swindler. His daughter may not have escaped the taint of heredity; it is, at all events, conceivable that her principles suffered from her early association with him. He is said to have died in South America, where he was obliged to fly to escape his just deserts, but there is no proof at all that he really did die.

“I know that I am for the moment dealing in theory, if I say, suppose this man to be secretly in London and in secret communication with his daughter. Suppose she let him see how direly she needed money at this moment. Might not a scoundrel of his description seize the opportunity to persuade her to help him in some such nefarious business as the robbery of Mrs. Vanderstein, and secure her silence, if not her assistance, in even a more dastardly business? To return to the realm of fact; the order to the motor not to fetch the ladies from the opera was given by Miss Turner. She ran back alone to tell the chauffeur, after your aunt had gone into the theatre. She had previously sent you this wire, in which she was very positive that the money you required would be forthcoming.

“She was seen by Miss Finner standing at the door of the house in Scholefield Avenue in the company of your aunt, and it is not too much to presume that she subsequently entered it with her. There would be no imaginable motive to induce a thief or gang of thieves to decoy her to the house: she had no jewels to be deprived of. There would be, on the contrary, every reason why she should be prevented from going anywhere near the place. Since, then, she assuredly went there on her own initiative, it seems probable that Mrs. Vanderstein was persuaded to accompany her by the girl herself.

“To go back for the moment to speculation, one may imagine that it was old Turner who masqueraded as West, the tenant, who is described as a horsey-looking elderly man who had lived much in a hot climate. This accords with a description of Turner I took the trouble to obtain yesterday, with the exception of the beard or imperial worn by West, which he may easily have grown of late years. It may have been the girl’s father, therefore, who opened the door to the two women, and who, once he had her safe inside, first locked your aunt in the library while he finished his preparations upstairs, and then led her to the drawing-room, as in times more in harmony with his deeds he might have led her to the nearest tree.

“Finally, in support of this theory, or at least of Miss Turner’s complicity in the affair, we have the facts that the two ladies were last seen together, and that, while the one has been found robbed and murdered, the other has departed without a word or a sign. It is only too likely that she is half way to America. The ports are being watched, but by now it is probably too late.”

Gimblet finished speaking and sat watching the face of the younger man. Sidney looked troubled, but his manner was confident as he gave his opinion.

“If she has not been heard of,” he said, “it is because for some reason she is unable to communicate with anyone. I have heard all your arguments attentively, Mr. Gimblet, and I must confess that you have not in the least convinced me that there is anything in your idea. It all sounds very plausible, no doubt, but if you knew the young lady as I have the pleasure of doing you would see that the whole thing is ridiculous. No one can be what she is and act in the way you suggest. Her nature is such as to put it out of the question. I can only repeat that the thing is ludicrously impossible, and that if you knew her you would be the first to see it. However, I agree with you that the best way of proving what I say is to find the real murderer. My only fear is that to-morrow you may discover that she too has been killed and buried in the garden.”

“I am not afraid of that,” said Gimblet, “because, as I tell you, if her presence had not been desirable she would never have been near the place. She would have been kept as unaware of its existence as you were yourself. The first essential of such a plan as the murderer must have concocted would be to get hold of Mrs. Vanderstein alone and unsuspected by anyone who was not a confederate.”

Sidney made an impatient movement.

“I am absolutely convinced that Miss Turner had nothing whatever to do with it,” he said.

“Well,” returned Gimblet as he rose to go, “I hope you are right and that further investigations will lead me to share your view. If we can lay hands on Mr. West we shall get at the truth, and unless he is very careful how he disposes of the jewels we are sure to catch him. From what I hear, Mrs. Vanderstein’s rope of pearls is well known to every jeweller in Europe; and, if he tries to sell so much as one of them, he’ll find a very different sort of rope around his neck. Now I must be off; they are expecting me at Scotland Yard.”