"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?"