“A skeleton key,” he repeated. “I discovered it before ever Sergeant John Ridgway had had a chance of looking for it, on the very spot where the poor thing’s body had lain. It must have been jerked from her hand—she had probably just produced it from her pocket—by the shot which killed her, and had remained there undetected during and after her removal. I was fortunate in securing it only a few minutes before the Sergeant came down to examine the place of the crime.

“Now, what had Annie Evans to do with a skeleton key—she, a modest servant girl of irreproachable character, as the housekeeper had just informed us? I examined the key. It was of the usual burglarious pattern, seemed newly turned, had a slight flaw, or projection, on the barrel end, and was splashed with an ugly Bluebeard red. Had Annie, after all, been quite the impeccable person Mrs. Bingley supposed? I wondered. I thought of the manner of her engagement, of her untraceable connexions, and I wondered. I wondered still at the Inquest, when, as it seemed, those same relations were still hopelessly to seek. I wondered no longer when, on the day following the inquiry, I came upon the Sergeant intently examining the ground about the scene of the crime. I came upon him unexpectedly, and surprised him. What was he looking for? He had already overhauled every detail of the girl’s belongings. Had he missed something which he had expected to find among them? A skeleton key possibly. But how could he have known she possessed such a thing? Obviously, there was only one answer—because he himself had provided her with it. For what reason—he, John Ridgway? Naturally, my mind flew off at a tangent to the other John Ridgway, my Parisian Jean, and his extraordinary story. A reputedly sham marriage which nevertheless had turned out genuine; documents in proof, and their possessor my host? Was it conceivable that this John Ridgway was interested in the recovery of those documents, and had employed a female confederate to steal them for him?

“It was quite conceivable, and quite true, for that, as appeared by degrees, was actually the case. But why was this John Ridgway interested in the recovery of those papers? We shall see.

“In the meanwhile, to what conviction had my reflections led me? That the detective and the girl were in collusion for a certain purpose. But much was to be deduced from that conviction—that the girl was an imposter, that she had secured her situation very possibly by means of a false character written by herself or her confederate, that, quite certainly, her name was not Annie Evans at all. Hence the calculated impossibility of tracing out her connexions.

“So far, then, so good. We come now to the frustrated business of the theft, and the crime which was its terrible consequence. It had inevitably occurred to me that the safe in Sir Calvin’s study must be the repository, and known by the confederates to be the repository, of the papers in question; else, if of easier access, they had long ago been abstracted and used to serve their purpose. Probably, as it appeared to me, the girl’s first business had been to secure an impression of the keyhole in wax, which she had despatched to Ridgway, receiving back from him in exchange the master-key. I seized an opportunity to examine the safe, and detected about the spot in question certain faint marks or scratches in the paint, which I had once before taken some curious stock of, and which I now perceived might well correspond with that little sharp projection I spoke of at the end of the key. I even once tried the key in the lock myself (that was on the night, Mr. Bickerdike, when you stalked me”—poor Vivian looked unutterably foolish—“but without detecting me in my second descent, which occurred after you had returned to your room) and found it easy to manipulate. Then the girl had already been secretly at work there, fumbling her job maybe? But why, in that case, had she not secured the plunder, given notice to leave, and at once cleared out? Because—as it was perfectly legitimate to infer from the evidence at the inquest—she had, in the meantime, fallen desperately in love with our young friend, and had refused to take any further part in a transaction designed to dispossess him of his name and inheritance.

“Now, that is to anticipate matters a little, perhaps; but grant my deduction sound—as, indeed, it proved to be—and what followed? Necessarily, a breach between the two confederates of a very violent nature. To the detective it meant betrayal and the ruin of his plans. Would that consideration be enough in itself to goad him on to murder? With a man of Ridgway’s character and trained cautiousness of disposition I did not think it probable. Assuming, then, that the murder were his act, what more overmastering motive could have driven him to it? What but jealousy, the one passion uncontrollable by even the most self-disciplining nature. He was himself passionately enamoured of his own beautiful decoy, and she had betrayed not only his interests but his love. The crime had been, in the expressive French phrase, and in the fullest sense, a crime passionel. I had it.

“To figure the course of events, even, was now no difficult task for the imagination. We will begin with Mrs. Bingley’s timely advertisement for a housemaid, upon which the confederates happened, and which gave them—perhaps suggested to them—the very opportunity they desired. Once the girl was established in the house, the two corresponded. We know that she received letters, though none could be found after her death. Of course not. She would have taken scrupulous care to destroy all such incriminating evidence, including the fraudulent ‘character.’ But they corresponded, and probably, on her part, very early in a tone which gave her accomplice to suspect, with growing uneasiness, that all was not right with her. Accident—it could have been nothing else—brought him down professionally and opportunely into this part of the country. He took the occasion to write and arrange for a secret personal interview with her—we had it from the housekeeper that a letter was received by Annie quite shortly before her death—and she answered appointing the Bishop’s Walk for their place of meeting. Of that I have no doubt. She was there to keep her engagement with Ridgway, and not to waylay the other. His appearance on the scene was quite fortuitous, and, as it turned out, the most fateful contretemps that could have happened. He came, and we know from his own confession what passed between them, with what she upbraided him, and with what threatened. Ridgway had overheard it all. He had arrived at the place duly to his appointment, and, on his first entering the copse, had probably heard, or perhaps caught distant sight of, the other male figure coming his way, and had slipped into the thick undergrowth for concealment. His propinquity unsuspected by the girl, she had delivered herself in his hearing of her deadly secret, and he knew at last of her double treachery to him. The lover gone, he came out of his ambush, and damned her with the truth. Likely, even then, it was the presence of the gun, so adversely left to his hand, which compelled him to the deed. It was the act of a demented moment, unthinking and unpremeditated. It was not until reason had returned to him that the idea of the diabolical vengeance it might be in his power to wreak on the seducer began to form in his mind. To bring the murder home to him! What a frenzy of triumph in the very thought! It possessed him devilishly, and verily from that moment it was as if the man had bargained away his soul to the evil one. Everything appeared to favour him—the mood, the motive, the conduct of his hated rival; most of all the fact that to his own hands, by some extraordinary freak of opportunism, had been committed the control of the case. How near he came to success in his inhuman design needs no retelling.

“But, meanwhile, there was the murder committed in that instant of madness. Probably he had not much hope at the time of escaping its consequences; probably, in his desperate state, with all his schemes gone to wreck, he did not much care. He had had his bloody revenge for an intolerable wrong, and the rest was indifference to him. He replaced the gun where it had stood, and left the spot. Possibly, as sanity returned to him, some instinct of self-preservation may have induced in him a certain mood of precaution. There is evidence to show, I think, that he lurked for a time in the woods before leaving them for the open hillside. But that he did leave them eventually to make his way up the hill, we have Henstridge’s evidence to testify.

“Now, from the first I had never succeeded in convincing myself that that hypothetical figure on the hill was as wholly a figment of the imagination as most people seemed to consider it. The cap pulled over the eyes and the turned-up collar—what butler ever turned up his coat collar?—were strong presumptions in my mind that Mr. Cleghorn had not been their wearer. Then the figure had been described as advancing hurriedly; yet it had taken twenty minutes or so to cover a distance of two hundred yards. You may object, possibly, that, in all your experience of Sergeant Ridgway, you have never seen him wear on his head other than a black plush Homburg hat. I answer that on the day of the murder he was wearing a cloth cap, easily, in the distance, to be mistaken for the cap worn by Mr. Cleghorn. I know this, because, in the course of one of my drives about the country in the company of a very charming young lady, I had made a point of calling at the Sergeant’s one-time lodgings at Antonferry—I had procured the address from Sir Calvin—where, at the cost of a little insinuative word-play, I was able to ascertain that the Sergeant had gone out, wearing a cloth cap, fairly early on the day of the murder, and that he had returned late, and seemingly in an exhausted condition, from a long walk. He had, and that hypothetical figure hurrying over the hill—at the moment with little concern for its safety—had been the figure of Sergeant Ridgway, tramping back to his lodgings in Antonferry after the murder. He had passed by the inn, making north by west, and had long turned the bend of the lonely road before Mr. Cleghorn, mistaken by Henstridge for the same figure, had arrived at the Red Deer and turned in at the tap.”

The Baron paused for refreshment, while Sir Francis applauded softly, his whole face beaming delight and approval.