"You seem surprised, Mr. Stanton!" exclaimed the inspector.

"I am surprised," I echoed, "and I intend to explain why presently. Meanwhile, I suppose you are trying to get on the track of the second man who lived in that tent?"

"That's what we are doing, sir–hard at it."

"You will never find him," I said.

"No, sir? May I ask what makes you so sure of that?"

"Simply because my opinion is that he does not exist–never did exist."

The inspector's jaw dropped. "But–but Mr. Carson Wildred—" he began, when I turned on him and cut him short.

"Did your experience never show you a case where a man, himself a criminal, invented proofs and clues for the purpose of putting the police upon the wrong track?"He too started from his chair, forgetting to set down his glass of whisky. "Good heavens, sir, you don't mean to accuse—"

"I don't accuse. I am not yet in a position to do that. I only suggest, and should be myself a criminal if I did not try to throw such light upon the matter as I can. Sit down again, inspector, and let me tell you what I know, and what I suspect."

He sat, or rather dropped into his lately-deserted chair, and his horrified expression, his drooping attitude, went far towards showing me what an exalted position Carson Wildred occupied in the esteem of the neighbourhood.

"I can't seem to realise it, Mr. Stanton," ejaculated the inspector. "Such a man as Mr. Wildred! So respected, so charitable, has given so much to the church! Why, you must be making a mistake."

"You shall judge for yourself whether I have any evidence to offer worth building upon," I returned. And then I told him everything, beginning with my chance meeting with Harvey Farnham at the theatre on Christmas Eve. His face grew graver and graver as I went on, and when at last (having dwelt with due insistence upon the mysterious proceedings attending my call at the House by the Lock) I mentioned the reappearance of the ring on "a young lady's finger," he shook his head regretfully.

"You've made out a fairly good case against Mr. Wildred, sir," he observed. "Would it be indiscreet to ask whether you've any personal enmity against the gentleman?"

"I don't like him," I admitted. And then I went on to describe in a few words my haunting impression of having been disagreeably associated with him in the past.

"I would wish," I added hurriedly, "to keep the name of the lady now in possession of the ring entirely out of the question if possible. It must only be brought in, inspector, at the last extremity should no other means remain of detecting a murderer. As for the ring itself, to save trouble in that direction, I think I could if necessary engage to get hold of it, and I am quite ready at any time to swear to its identity with the one worn by my old friend Farnham."

The inspector thoughtfully scratched his head. "It'll be a nasty business to examine Mr. Wildred's house, in case your friend Mr. Farnham should prove to be all right over in the States. But we can't lose any time. What you've told me to-day is very serious, sir, and must be attended to at once. A couple of detectives will call at the House by the Lock with a search-warrant before nightfall. I can assure you of that. Until some definite conclusion is arrived at, Mr. Stanton, I suppose you would prefer that your name didn't appear in the matter?"

"I don't care a hang whether it appears or not," I retorted recklessly. Perhaps if I had been a little less reckless–but it is never profitable to dwell on and brood over the mistakes of one's past.

The inspector assured me that a detective should call that night at the hotel in Great Marlow where I had volunteered to remain, and give me all particulars concerning the examination of the House by the Lock. The appointment made was for eight o'clock, by which time, allowing for obstacles and unforeseen delays, all was sure to be well over.

Though the inspector had promised that the New York police should be communicated with, a great restlessness was upon me, and I resolved myself to cable to America.

It was possible that the St. Paul, the ship in which Farnham had been supposed to sail, was arriving at New York that day, though the chances were, as the weather had been rough, that she would not have made one of her record trips. However, there could be no harm in wiring, and if the ship had got in all waste of time would be avoided.

I wrote out a despatch to the office of the American line in New York, to be answered (reply prepaid) the moment the St. Paul got in. In this I enquired whether Mr. Harvey Farnham, of Denver, Colorado, had been among the passengers. And not contenting myself with this I cabled Farnham, both to Denver and New York, and to the manager of the Fifth Avenue Hotel in the latter place, where I had been told that he usually put up.

The answers to these messages I requested to have sent me at the hotel I had chosen for my headquarters in Great Marlow.

The hours which must intervene before I could possibly hope for a return I spent at the Wayfarers', and there I heard of Wildred, who had lunched at the club with his friend Wigram, and later had been interrupted during a game of billiards by a telegram. He had used some strong language, and hurriedly excusing himself, had left in the midst of the game.

Things had evidently been put into train early, I told myself with satisfaction, and I concluded that the despatch had either gone out from police headquarters or been sent by that stealthy-faced, invaluable major-domo of Wildred's.

By half-past five I was in the train again, carrying with me all that I could want for the stay of a day or two in a strange hotel, and before eight o'clock I had dined and was anxiously awaiting the appearance of the detective. I had hardly dared to hope as yet for any answer to my cablegrams, still I was disappointed to find upon my advent in Great Marlow that nothing had arrived.

Every step along the corridor outside the private sitting-room I had taken made me start like a nervous woman, fancying each time that a knock on my door might follow and the wished-for message be handed in to me.

I did not believe that I should hear from Farnham, because my conviction was steadily growing that his murdered body lay unidentified in the mortuary not far away. But I did expect to hear from the ship's company to the effect that no such passenger had been on board the St. Paul. Should this intelligence arrive, there would be so great an increase of the circumstantial evidence against Wildred that I believed the police would be justified in making an arrest. Wildred once arrested and obliged to stand his trial for the crime of murder, Karine Cunningham would be saved.

Eight o'clock struck, however, and I was reluctantly obliged to give up all idea of receiving any news from America for the night. Five minutes later, as I restlessly paced the room, the wished-for knock sounded, but there was no cablegram to be presented on a tray. A young, fresh-faced man in plain clothing stood there, who I knew before he spoke must be the expected detective. His information might prove of equal importance with the tidings from America, and I received him cordially.

With his first words, however, my heart went down like lead. It was not that I was eager to see a presumably innocent man proved a murderer for the sake of my own selfish ends, but thoroughly believing Wildred to be a consummate scoundrel, I was anxious that he should be found out in time to prevent disaster.

"I think sir," said the young man of the cheerful countenance, "that we've been on a false scent to-day."

I got him to sit down, and launched him upon the full tide of narrative.

"Mr. Wildred was away when we first arrived at the House by the Lock, sir," he went on, "but we should have made use of our search-warrant without waiting for his return had not the passage and the octagonal room you described, as well as the tower, been shut off from all communication with the older part of the house by a heavy iron door, of which Mr. Wildred invariably carries the key. This his butler explained by saying that the door had been placed on account of his master's chemical experiments, which were sometimes of a slightly dangerous character, unless great precautions were used, and in case of an explosion or other accident the safety of the living-rooms might be assured by means of the iron door. The only way of opening it would have been to employ dynamite, the lock being impregnable; and as the grounds for suspicion against Mr. Wildred were not yet strong enough to resort to such violent means, there was nothing to do but wait. He was wired for to London at once."

"Naturally he would prefer being on the spot," I said, with something like a sneer. "All the same, I am very sure that there is another means of communicating with the octagonal room and the tower besides the main door through the passage." And I mentioned the mysterious disappearance of the servant, which had on Christmas Day led me to believe in the existence of a secret way of exit.

"We did look about for something of the sort, and even went down a cellar," said the detective, "but saw not the slightest sign to suggest a hidden door."

"Well, go on then to Mr. Wildred's return," I exclaimed impatiently. "I am anxious to learn why it has been decided that I put you on the wrong track."

"When he came home he admitted very frankly that he had been annoyed at the bother occasioned by our telegram, but appeared by that time to have recovered from his vexation, and to be inclined to laugh the matter off. He let us know in a moment that he guessed how the information had come, but we said nothing, of course, to confirm his suppositions.

"In the first place he opened the iron door, explained its workings as though he took some pride in its mechanism, which he said he had invented himself. Then he showed us into the octagonal room, which he had had fitted up as a studio and smoking-room combined. The little door you had seen behind the drapery merely led into a cupboard containing boots, an artist's model–a jointed figure of wood–and other odds and ends. It was concealed only because it was not 'an object of beauty,' Mr. Wildred said.

"We then proceeded to the tower, where the chemical experiments are made. There is a small room, reached by mounting a winding skeleton stairway of iron, and there we were shown Mr. Wildred's apparatus. I know something of chemistry myself, having had a fad that way when I was a boy, and I could see that everything he had was straight and above-board. A big fireplace in the room accounts for the sparks you saw when you approached the house that day, and Mr. Wildred voluntarily mentioned that there had been something wrong with the flues, so that his experiments could not be conducted properly, and he had sent for an expert to come down from London to look at everything. The man had been expected on Christmas Eve, then on Christmas, as Mr. Wildred considered the matter urgent, and finally arrived the day after. Mr. Wildred gave us his address without waiting to be asked to do so. That accounted for one more point in your story, sir–the man who was so anxiously looked for, the man the butler seemed at first to take you to be.

"We then said we had been informed that screams or groans had been heard issuing from his house on Christmas Day. Mr. Wildred laughed, remarking that, judging from what he knew of our informant, he had been waiting for us to come to that point.

"And he repeated the explanation which had been given you, asking us also if we would care to see the scar (which was not yet quite healed) made by the burning methylated spirit on the cook's foot or ankle.

"We thought it best to do as he suggested–indeed, if he had not, we should have proposed the same course ourselves, for the sake of making assurance doubly sure. The cook was sent for, a very handsome young woman, sir, bright and ready with her answers. She described the accident, and whipping off the shoe and stocking from the right foot, showed us a red mark which spread from the ankle down over the whole instep."

"So the cook was a handsome young woman, was she?" I asked, suspiciously, remembering the face which had peered at me through the narrow window by the door. "Had she great black eyes, a very white face, and a quantity of dark hair?"

"She had, sir. That would describe her very well. A woman not more than twenty-five or six, and evidently of a superior class."

I turned this bit of information over in my mind. To be sure, I could not at the moment make anything of it apropos of the case in hand, but afterwards I was to remember it under somewhat startling circumstances.

"So you see, sir," the detective continued, "every point you made was met, and in our opinion, frankly and sufficiently met. Nothing was found which could possibly justify an arrest, and unless unfavourable reports are received from the New York police, the case against Mr. Wildred will have to be dropped. The inspector is having an interview with him to-night, and doubtless some details with which we, in enforcing our search-warrant, had no concern will be satisfactorily cleared up. I mean to say, details relating to the American gentleman, his ring, and his departure for the States. Should we hear from New York that he has not returned, why of course, in spite of appearances at the House by the Lock and failure of circumstantial evidence, suspicion will be renewed again."

There was absolutely nothing more to be said. Deep as was my chagrin, I held my tongue as to my opinion of the way affairs had been managed, and parted with the young detective with apparent nonchalance.

Naturally, I slept little during the night, and was awake even before the early knock which sounded at my door.

"Two cablegrams for you, sir," said the waiter, when I had bidden him come in.