“Hm-m-m!” said Cleek again.  “And were all the symptoms—­or, rather, the absence of symptoms—­the same?”

“Precisely.  All the organs were discovered to be in a normal condition, the blood was untainted by any suggestion of either mineral or animal poison, the heart was sound, the lungs healthy—­there was neither an internal disturbance nor an external wound, unless one could call a ‘wound’ a slight, a very slight, swelling upon the left side of the neck; a small thing, not so big as a sixpence.”

“And appearing very much like the inflammation resulting from the bite of a gnat or a spider, Captain?”

“Exactly like it, Mr. Cleek.  In fact, the doctors fancied at first that it was the result of his having been bitten by some poisonous insect, and were for accounting for his death that way.  But, of course, the entire absence of poison in the blood soon put an end to that idea, so it was certain that whatever he died from, it was not from a bite or a sting of any sort.”

“Clever chaps, those doctors,” commented Cleek with a curious one-sided smile.  “However, they were quite correct in that, I imagine, poison, either animal, vegetable, or mineral, was not the means of destruction.  Still, I should have thought that at this second post-mortem the likeness of the son’s case to that of the mother’s would have impelled them to extra vigilance, and resulted in a much more careful searching, and minute examination of the viscera.  If my theory is correct, I do not suppose they would have found anything in the contents of the thorax or the abdomen, but it is just possible that analysis of the matter removed from the cranial cavity might have revealed a small blood-clot in the brain.”

The Captain twitched up his eyebrows and stared at him in open-mouthed amazement.

“Of all the—­By Jove! you know, this beats me!  To think of your guessing that!” he said.  “As a matter of fact, that’s precisely what they did do, Mr. Cleek.  But as they couldn’t arrive at any conclusion nor trace a probable cause of its origin they were more in the dark than ever.  Selwin, the local practitioner, was for putting it down as a case of apoplexy on the strength of that small blood-clot, but as there was an entire absence of every other symptom of apoplectic conditions the other doctors scouted the suggestion as preposterous—­pointed out the generally healthy state of the brain and of the heart, lungs, arterial walls, et cetera, as utterly refuting such a theory—­and in the end the verdict on the son was the verdict given on the mother:  ’Death from unknown causes’; and he was buried as she had been buried, with the secret of the murder undiscovered.”

“And then what, Captain?”