“I thank you,” said the doctor, with some dignity.  “I think you will trust him when you have talked to him a little.  And now,” he added with an air of amiably relaxing into lighter matters, “let us talk about the murder.

“This case,” he said in a detached manner, “will be found, I suspect, to be rather unique.  There is a very clear and conclusive combination of evidence against Thomas Burton Brown, otherwise myself.  But there is one peculiarity about that evidence, which you may perhaps have noticed.  It all comes ultimately from one source, and that a rather unusual one.  Thus, the woodcutter says I had his ax, but what makes him think so?  He says I told him I had his ax; that I told him so again and again.  Once more, Mr. Paynter here pulled up the ax out of the well; but how?  I think Mr. Paynter will testify that I brought him the tackle for fishing it up, tackle he might never have got in any other way.  Curious, is it not?  Again, the ax is found to be wrapped in lint that was in my possession, according to the fisherman.  But who showed the lint to the fisherman?  I did.  Who marked it with large letters as mine?  I did.  Who wrapped it round the handle at all?  I did.  Rather a singular thing to do; has anyone ever explained it?”

His words, which had been heard at first with painful coldness were beginning to hold more and more of their attention.

“Then there is the well itself,” proceeded the doctor, with the same air of insane calm.  “I suppose some of you by this time know at least the secret of that.  The secret of the well is simply that it is not a well.  It is purposely shaped at the top so as to look like one, but it is really a sort of chimney opening from the roof of one of those caves over there; a cave that runs inland just under the wood, and indeed is connected by tunnels and secret passages with other openings miles and miles away.  It is a sort of labyrinth used by smugglers and such people for ages past.  This doubtless explains many of those disappearances we have heard of.  But to return to the well that is not a well, in case some of you still don’t know about it.  When the sea rises very high at certain seasons it fills the low cave, and even rises a little way in the funnel above, making it look more like a well than ever.  The noise Mr. Paynter heard was the natural eddy of a breaker from outside, and the whole experience depended on something so elementary as the tide.”

The American was startled into ordinary speech.

“The tide!” he said.  “And I never even thought of it! 
I guess that comes of living by the Mediterranean.”

“The next step will be obvious enough,” continued the speaker, “to a logical mind like that of Mr. Ashe, for instance.  If it be asked why, even so, the tide did not wash away the Squire’s remains that had lain there since his disappearance, there is only one possible answer.  The remains had not lain there since his disappearance.  The remains had been deliberately put there in the cavern under the wood, and put there after Mr. Paynter had made his first investigation.  They were put there, in short, after the sea had retreated and the cave was again dry.  That is why they were dry; of course, much drier than the cave.  Who put them there, I wonder?”