Gurdon nodded thoughtfully. He was trying to piece the puzzle together in his mind, but so far without success. He was not in the least surprised to find that Venner had guessed correctly.

"You've got it exactly," he said. "That is just what the gruesome thing is. What does it all mean?"

By this time dinner had long been a thing of the past, and all the guests had departed. Here and there the lights were turned down, leaving half the room in semi-darkness. It was just the time and place for an exchange of confidences.

"How did you know exactly what was in that box?" Gurdon asked. "I have read things of this kind before, but they have generally taken the form of a warning previous to some act of vengeance."

"As a matter of fact, this is something of the same kind," Venner said; "though I am bound to say that my guess was somewhat in the nature of a shot. Still, putting two and two together, I felt that I could not have been far wrong. Since I have been here this evening, I have begun to form a pretty shrewd opinion as to where Fenwick gets his money."

"What shall we do with that box?" Gurdon asked.

"Leave it where it is, by all means. You may depend upon it that Fenwick will return for his lost property."

The prophecy came true quicker than Gurdon had expected, for out of the gloom there presently emerged the yellow face of Mark Fenwick. He came in with a furtive air, like some mean thief who is about to do a shabby action. He was palpably looking for something. He made a gesture of disappointment when he saw that the table where he had dined was now stripped of everything except the flowers. He did not seem to see the other two men there at all. Venner took the box from his companion's hand, and advanced to Fenwick's side.

"I think you have lost something, sir," he said coolly. "Permit me to restore your property to you."

The millionaire gave a kind of howl as he looked at Venner. The noise he made was like that of a child suffering from toothache. He fairly grovelled at Venner's feet, but as far as the latter's expression was concerned, the two might have met for the first time. Just for a moment Fenwick stood there, mopping his yellow face, himself a picture of abject misery and despair.

"Well?" Venner said sharply. "Is this little box yours, or not?"

"Oh, yes, oh yes," Fenwick whined. "You know that perfectly well—I mean, you must recognise—oh, I don't know what I mean. The fact is, I am really ill to-night. I hardly know what I am doing. Thank you, very much."

Fenwick snatched the box from Venner's fingers, and made hastily for the door.

"I believe we are allowed to smoke in here after ten," Gurdon said. "If that is the case, why not have a cigar together, and discuss the matter? What I am anxious to know at present is the inner meaning of the finger in the box."

There was no objection to a cigar in the dining-room at this late hour, and presently the two friends were discussing their Havanas together. Venner began to speak at length.

"Perhaps it would be as well," he said, "to stick to the box business first. You will remember, some three years ago, my writing you to the effect that I was going to undertake a journey through Mexico. I don't suppose I should have gone there at all, only I was attracted by the notion of possible adventures in that country, among the hills where, at one time, gold was found. There was no question whatever that gold in large quantities used to be mined in the wild district where I had chosen to take up my headquarters. Practical engineers say that the gold is exhausted, but that did not deter me in the least.

"The first man who put the idea into my head was a half-caste Mexican, who had an extraordinary grip on the history of his country, especially as far as legends and traditions were concerned. He was a well-educated man, and an exceedingly fascinating story-teller. It was he who first gave me the history of what he called the Four Finger Mine. It appears that this mine had been discovered some century or more ago by a Frenchman, who had settled down in the country and married the daughter of a native chief. The original founder of the mine was a curious sort of man, and was evidently possessed of strong miserly tendencies. Most men in his position would have gathered together a band of workers, and simply exploited the mine for all it was worth. However, this man, Le Fenu, did nothing of the kind. He kept his discovery an absolute secret, and what mining was to be done, he did himself. I understand that he was a man of fine physique, and that his disposition was absolutely fearless. It was his habit at certain seasons of the year to go up to his mine, and there work it for a month or two at a time, spending the rest of the year with his family. It is quite certain, too, that he kept his secret, even from his grown-up sons; for when he died, they had not the slightest idea of the locality of the mine, which fact I know from Le Fenu's descendants.

"And now comes the interesting part of my story, Le Fenu went up into the mountains early in May one year, to put in his solitary two months' mining, as usual. For, perhaps, the first time in his life, he suffered from a serious illness—some kind of fever, I suppose, though he had just strength of will enough to get on the back of a horse and ride as far as the nearest hacienda.

"Now, on this particular farm there dwelt a Dutchman, who, I believe, was called Van Fort. Whether or not Le Fenu partially disclosed his secret in his delirium, will never actually be known. At any rate, two or three weeks later the body of Le Fenu was discovered not very far away from the scene of his mining operations, and from the evidence obtainable, there was no doubt in the world that he was foully murdered. Justice in that country walks with very tardy footsteps, and though there was little question who the real murderer was, Van Fort was never brought to justice. Perhaps that was accounted for by the fact that he seemed to be suddenly possessed of more money than usual, and was thus in a position to bribe the authorities.

"And now comes a further development. Soon after the death of Le Fenu, it was noted that Van Fort spent most of his time away from his farm in the mountains, no doubt prospecting for Le Fenu's mine. Whether he ever found it or not will never be known. Please to bear in mind the fact that for a couple of centuries at least Le Fenu's mysterious property was known as the Four Finger Mine. With this digression, I will go on to speak further of Van Fort's movements. To make a long story short, from his last journey to the mountains he never returned. His widow searched for him everywhere; I have seen her—a big sullen woman, with a cruel mouth and a heavy eye. From what I have heard, I have not the slightest doubt that it was she who inspired the murder of the Frenchman.

"She had practically given up all hope of ever seeing her husband again, when, one dark and stormy night, just as she was preparing for bed, she heard her husband outside, screaming for assistance. From his tone, he was evidently in some dire and deadly peril. The woman was by no means devoid of courage; she rushed out into the night and searched far and near, but no trace of Van Fort could be found, nor did the imploring cry for assistance come again. But the next morning, on the doorstep lay a bleeding forefinger, which the woman recognised as coming from her husband's hand. To make identity absolutely certain, on the forefinger was a ring of native gold, which the Dutchman always wore. Please to remember once more that this mine was known as the Four Finger Mine."

Venner paused just for a moment to give dramatic effect to his point. Gurdon said nothing; he was too deeply interested in the narrative to make any comment.

"That was what I may call the first act in the drama," Venner went on. "Six months had elapsed, and Van Fort's widow was beginning to forget all about the startling incident, when, one night, just at the same time, and in just the same circumstances, came that wild, pitiful yell for assistance outside the Dutchman's farm. Half mad with dread and terror the woman sat there listening. She did not dare to go outside now; she knew how futile such an act would be. Also, she knew quite well what was going to happen in the morning. She sat up half the night in a state bordering on madness. I need not insult your intelligence, my dear fellow, by asking you to guess what she found on the doorstep in the daylight."

"Of course, I can guess," Gurdon said. "Beyond all question, it was the third finger of the Dutchman's hand."

"Quite so," Venner resumed. "I need not over elaborate my story or bore you by telling how, six months later, the second finger of the hand appeared in the same sensational circumstances, and how, at the end of a year, the four fingers were complete. Let me once more impress upon you the fact that this mine was called the Four Finger Mine for more than a century before these strange things happened."

"It is certainly an extraordinary thing," Gurdon muttered. "I don't think I ever listened to a weirder tale. And did the Dutch woman confess to her crime? This strikes me as being a fitting end to the story. I suppose it came from her lips."

"She didn't confess, for the simple reason that she had no mind to confess with," Venner explained. "Of course, certain neighbors knew something of what was going on, but they never knew the whole truth, because, after the appearance of the last finger, Mrs. Van Fort went stark raving mad. She lived for a few days, and at the end of that time her body was found in a waterfall close to her house. That is the story of the Four Finger Mine so far as it goes, though I should not be surprised if we manage to get to the last chapter yet. Now, you are an observant man—did you notice anything peculiar in Fenwick's appearance to-night?"

Gurdon shook his head slowly. It was quite evident that he had not noticed anything out of the common in the appearance of the millionaire. Venner proceeded to explain.

"Let me tell you this," he said. "When I married my wife, we were within an easy ride of the locality where the Four Finger Mine is situated. Mind you, our marriage was a secret one, and I presume that Fenwick is still in ignorance of it, though, of course, he was fully aware of the fact that I had more than a passing admiration for Vera. I merely mention this by way of accentuating the little point that I am going to make. It is more than probable that, when I stumbled upon Fenwick and the girl who passes for his daughter, he also was in search of the Four Finger Mine. When he came in to-night he, of course, recognised me, though I treated him as an absolute stranger whom I had met for the first time. You will see presently why I treated him in this fashion. I am glad I spoke to him, because I noticed a slight thing that throws a flood of light upon the mystery. Now, did it escape your observation, or did you notice that Fenwick took the box I gave him in his right hand?"

"Oh, dear, no," Gurdon said. "A little thing like that would be almost too trivial for the typical detective of the cheap story."

"All the same, it is very important," Venner said. "He took the box in his right hand; he made as if to extend his left, then suddenly changed his mind, and put it in his pocket. But he was too late to disguise from me that he had—"

"I know," Gurdon shouted. "He had lost all the fingers on his left hand. What an amazing thing! We must get to the bottom of this business at all costs."

"That is precisely what we are going to do," Venner said grimly. "I am glad you are so quick in taking up the point. When I noted the loss of those fingers, I was absolutely staggered for a moment. If he had been less agitated than he was, Fenwick would have guessed what I had seen. I need not tell you that when I last saw Fenwick his left hand was as sound as yours or mine. The inference of this is, that Fenwick has fallen under the ban of the same strange vengeance that overtook Van Fort and his wife. There is not the slightest doubt that he discovered the mine, and that he has not yet paid the penalty for his temerity."

"I presume the penalty is coming," Gurdon said. "What a creepy sort of idea it is, that terrible vengeance reaching across a continent in such a sinister fashion. But don't forget that we know something as to the way in which this thing is to be brought about. Don't forget the cripple who sat at yonder table to-night."

"I am not likely to forget him," Venner observed. "All the more because he evidently knows more about this matter than we do ourselves. When he came here to-night, he little dreamed that there was one man in the room, at least, who had a fairly good knowledge of the Four Finger Mystery. We shall have to look him out, and, if necessary, force him to speak. But it is a delicate matter, and as far as I can see, one not unattended with danger."

Gurdon smoked in thoughtful silence for some little time, turning the strange thing over in his mind. The more he dwelt upon it, the more wild and dramatic did it seem.

"There is one thing in our favor," he said, presently. "The mysterious cripple is evidently a deadly enemy of Fenwick's. We shall doubtless find him ready to accept our offer, provided that we put it in the right way."

"I am not so sure of that," Venner replied. "At any rate, we can make no move in that direction without thinking the whole thing out carefully and thoroughly. Our crippled friend is evidently a fanatic in his way, and he is not alone in his scheme. Do not forget that we have also the little man who played the part of the waiter to deal with. I am sorry that I did not notice him. A man who could carry off a thing like that with such splendid audacity is certainly a force to be reckoned with."

Gurdon rose from his seat with a yawn, and intimated that it was time to go to bed. It was long past twelve now and the hotel was gradually retiring to rest. The Grand Empire was not the sort of house to cater to the frivolous type of guest, and usually within an hour of the closing of the theatres the whole of the vast building was wrapped in silence.

"I think I will go now," Gurdon said. "Come and lunch with me to-morrow, and then you can tell me something about your own romance. What sort of a night is it, waiter?"

"Very bad, sir," the waiter replied. "It's pouring in torrents. Shall I call you a cab, sir?"