as I shall tell in the proper place; but even then the real secret remained hidden from us till the appointed end.
So ended the case of Samuel's diamonds, so far as concerned Samuel himself and the owner; but the case of the Red Triangle had only begun.
THE CASE OF MR. JACOB MASON
I
The mystery of Denson's death remained a mystery, despite all the police could do. The coroner's jury returned a verdict of "Murder by some person or persons unknown" – which, indeed, was all that could be expected of them; for they had no more before them than the bare fact that the body, disguised in the clothes of a labourer, had been found on the steps near the Duke of York's column, just before midnight, by a police constable. But for the housekeeper's identification, even the name of the victim would have been unknown. The jury certainly wasted some time in idle speculation as to the strange triangular mark found on the forehead, without a speck of evidence to help them; but in the end they returned their verdict, and went home.
But the police knew a little more than the jury, though that little rather confused than helped them. They exercised their judgment at the inquest in withholding all evidence of the theft of diamonds on which the victim had been engaged, the curious particulars of which I have already related. In this they followed their usual course in cases where the evidence withheld could give the jury no help in arriving at their verdict, and at the same time might easily hamper further investigations if revealed. For the theft had been frustrated by Martin Hewitt's exertions, as we have seen, and in any case the thief was now dead and beyond the reach of human punishment. The one matter now remaining for the police was inquiry into the murder of this same thief, and the one object of their exertions the apprehension of the murderer or murderers.
The case, as I have already said, was in the hands of Inspector Plummer, an intelligent officer and an old friend of Hewitt's. A few days' work after the inquest yielded Plummer so little result that he called at Hewitt's office to talk matters over.
"I suppose," Plummer began, "it's no use asking if you've heard anything more of that matter of Denson's murder?"
Hewitt shook his head. "I haven't heard a word," he said. "If I had, it would have come on to you at once. But I hope you've had some luck yourself?"
"Not a scrap; time wasted; and the few off-chance clues I tried have led nowhere, so that I'm where I was at the start. The thing is quite the oddest in all my experience. See how we stand. Here's a man, Denson, who has just pulled off one of the cleverest jewel robberies ever attempted. He so arranges it that he walks safely off with fifteen thousand pounds' worth of diamonds, leaving the victim, Samuel, stuck patiently in an office for an hour or two before he even begins to suspect anything is wrong, and then unable to set the police after him, for the reasons you discovered. But this Denson doesn't carry the plunder off straightway, as he so easily might have done – he conceals it in the very house where the robbery was committed, taking with him a key by aid of which he may return and get it. Why? As you explained, it was probably because he feared somebody – feared being stopped and searched on the day of the robbery– not after, since it was plain he meant to return for his booty at night. Who could this have been, and why did Denson fear him? Mystery number one. Then this Denson is found dead that same night disguised in the clothes of a labourer, in a most conspicuous spot in London – the last place in the world one would expect a murderer to select for depositing his victim's body, for it is evidently not the place where the murder was committed. More, on the forehead there is this extraordinary impressed mark of a Red Triangle. Now, what can all that mean? Robbery, perhaps one thinks. But the body isn't robbed! There are three five-pound notes on it, besides a sovereign or two and some small change, a watch and chain, keys and all the rest of it. Then one guesses at the diamonds. Perhaps it was an accomplice in the robbery, who finds that Denson is about to bolt with the whole lot. But if there's one thing plain in this amazing business it is that Denson had no accomplice; he did the whole thing alone, as you discovered, and he needed no help. More than that, if this were the work of an accomplice why didn't he get the jewels? There were the keys to his hand and he left them! And would such a person actually go out of his way to put the body where it must be discovered at once, instead of concealing it till he could himself get away with the diamonds? Of course not. But there was no accomplice, and it's useless to labour that farther. All these arguments apply equally against the theory that it was the work of some criminal gang. They would have taken all they could get, notes, keys, diamonds and all, and they wouldn't have been so foolish as to exhibit the body with that extraordinary mark; criminal gangs are not such fools as to take unnecessary chances and gratuitously leave tracks behind them, as you know well enough. Well then, there we stand. So far, do you see any more in it than I do?"
Hewitt shook his head. "No," he said, "I can't say I do. All the considerations you have mentioned have already occurred to me. I talked them over, in fact, with my friend Brett. My connection with the case ceased, of course, with the discovery of the jewels, and about the murder I know no more than has been told me. I never saw the body, and so had no opportunity of picking up any overlooked clue; though doubtless you have seen to that. I know not a tittle more than you have just summarised, and on that alone the thing seems mystery pure and unadulterated."
"All there is beyond that was ascertained by the divisional surgeon on examination of the body. The man died from strangulation, as you know, and the natural presumption from that was that the murderer must have been a powerful man. But the surgeon is of the positive opinion – he is certain, in fact – that Denson was strangled with an instrument – a tourniquet."
"A tourniquet?"
"Yes, a surgeon's tourniquet, such as is used to compress a leg or arm and so stop a flow of blood. He considers the marks unmistakable. Now that might point to the murderer being a medical man."
"Conjecturally, yes; though, of course, it justifies nothing more than conjecture."
"Precisely. Well, that was something, but precious little. A tourniquet is a common thing enough – no more than a band with screw fittings, and there was nothing to show that the tourniquet used was any different from a thousand others; and I can see no particular reason why a doctor should commit a murder like this any more than any other man; in which the divisional surgeon agreed with me. And doctor or none, that Red Triangle was altogether unaccounted for. About that, too, by the way, the divisional surgeon told me a little, but a very useless little. The mark was not properly dried, owing to its slightly greasy nature, and although it was almost impossible to remove it wholly, it was possible to scrape off a little of the ink, or colour. Here is a little of it on a paper – quite dried now, of course."
Plummer carefully took from his pocket a small folded paper, unfolded it, and revealed a smaller paper within. On this were two little smears of a bright red colour. "There – that's the stuff," he said. "The surgeon examined it, and he reports it to be rather oddly constituted – so as to bear some affinity of meaning, possibly, to the triangle. For the stuff is a compound of three substances – animal, vegetable and mineral; there is a fine vegetable oil, he says, some waxy preparation, certainly of animal origin, and a mineral – cinnabar: vermilion, in fact. But though there may be some connection between the triangle and the substances representing the three natural kingdoms, it gives nothing practical – nothing to go on."
Martin Hewitt had been closely examining the marks on the paper, and now he answered, "I'm not so sure of that, though, Plummer. I think at least that it gives us another conjecture. I should guess that the man you want, as well as being acquainted with the use of the tourniquet, has at some time travelled in, or to, China."
"Why?"
"Unless I am wider of the mark than usual, this is the pigment used on Chinese seals. A Chinaman's seal acts for his signature on all sorts of documents; it is impressed or printed by hand pressure from a little
