"Our next obvious step is to check, so far as we can, the movements of Mortimer Tregennis after he left the room. In this there is no difficulty, and they seem to be above suspicion. Knowing my methods as you do, you were, of course, conscious of the somewhat clumsy water-pot expedient by which I obtained a clearer impress of his foot than might otherwise have been possible. The wet, sandy path took it admirably. Last night was also wet, you will remember, and it was not difficult – having obtained a sample print – to pick out his track among others and to follow his movements. He appears to have walked away swiftly in the direction of the vicarage.

"If, then, Mortimer Tregennis disappeared from the scene, and yet some outside person affected the card players, how can we reconstruct that person, and how was such an impression of horror conveyed? Mrs. Porter may be eliminated. She is evidently harmless. Is there any evidence that someone crept up to the garden window and in some manner produced so terrific an effect that he drove those who saw it out of their senses? The only suggestion in this direction comes from Mortimer Tregennis himself, who says that his brother spoke about some movement in the garden. That is certainly remarkable, as the night was rainy, cloudy, and dark. Anyone who had the design to alarm these people would be compelled to place his very face against the glass before he could be seen. There is a three-foot flower border outside this window, but no indication of a footmark. It is difficult to imagine, then, how an outsider could have made so terrible an impression upon the company, nor have we found any possible motive for so strange and elaborate an attempt. You perceive our difficulties, Watson?"

"They are only too clear," I answered with conviction.

"And yet, with a little more material, we may prove that they are not insurmountable," said Holrnes. "I fancy that among your extensive archives, Watson, you may find some which were nearly as obscure. Meanwhile, we shall put the case aside until more accurate data are available, and devote the rest of our morning to the pursuit of Neolithic man."

I may have commented upon my friend's power of mental detachment, but never have I wondered at it more than upon that spring morning in Cornwall when for two hours he discoursed upon Celts, arrowheads, and shards, as lightly as if no sinister mystery were waiting for his solution. It was not until we had returned in the afternoon to our cottage that we found a visitor awaiting us, who soon brought our minds back to the matter in hand. Neither of us needed to be told who that visitor was. The huge body, the craggy and deeply seamed face with the fierce eyes and hawk-like nose, the grizzled hair which nearly brushed our cottage ceiling, the beard – golden at the fringes and white near the lips, save for the nicotine stain from his perpetual cigar – all these were as well known in London as in Africa, and could only be associated with the tremendous personality of Dr. Leon Sterndale, the great lion-hunter and explorer.

We had heard of his presence in the district and had once or twice caught sight of his tall figure upon the moorland paths. He made no advances to us, however, nor would we have dreamed of doing so to him, as it was well known that it was his love of seclusion which caused him to spend the greater part of the intervals between his journeys in a small bungalow buried in the lonely wood of Beauchamp Arriance. Here, amid his books and his maps, he lived an absolutely lonely life, attending to his own simple wants and paying little apparent heed to the affairs of his neighbors.

It was a surprise to me, therefore, to hear him asking Holmes in an eager voice whether he had made any advance in his reconstruction of this mysterious episode. "The county police are utterly at fault," said he, "but perhaps your wider experience has suggested some conceivable explanation. My only claim to being taken into your confidence is that during my many residences here I have come to know this family of Tregennis very well – indeed, upon my Cornish mother's side I could call them cousins – and their strange fate has naturally been a great shock to me. I may tell you that I had got as far as Plymouth upon my way to Africa, but the news reached me this morning, and I came straight back again to help in the inquiry."

Holmes raised his eyebrows. "Did you lose your boat through it?"

"I will take the next."

"Dear me! that is friendship indeed."

"I tell you they were relatives."

"Quite so – cousins of your mother. Was your baggage aboard the ship?"

"Some of it, but the main part at the hotel."

"I see. But surely this event could not have found its way into the Plymouth morning papers."

"No, sir; I had a telegram."

"Might I ask from whom?"

A shadow passed over the gaunt face of the explorer. "You are very inquisitive, Mr. Holmes."

"It is my business."

With an effort Dr. Sterndale recovered his ruffled composure. "I have no objection to telling you," he said. "It was Mr. Roundhay, the vicar, who sent me the telegram which recalled me."

"Thank you," said Holmes. "I may say in answer to your original question that I have not cleared my mind entirely on the subject of this case, but that I have every hope of reaching some conclusion. It would be premature to say more."

"Perhaps you would not mind telling me if your suspicions point in any particular direction?"

"No, I can hardly answer that."

"Then I have wasted my time and need not prolong my visit." The famous doctor strode out of our cottage in considerable ill-humor, and within five minutes Holmes had followed him. I saw him no more until the evening, when he returned with a slow step and haggard face which assured me that he had made no great progress with his investigation.

He glanced at a telegram which awaited him and threw it into the grate. "From the Plymouth hotel, Watson," he said. "I learned the name of it from the vicar, and I wired to make certain that Dr. Leon Stemdale's account was true. It appears that he did indeed spend last night there, and that he has actually allowed some of his baggage to go on to Africa, while he returned to be present at this investigation. What do you make of that, Watson?"

"He is deeply interested."

"Deeply interested – yes. There is a thread here which we have not yet grasped and which might lead us through the tangle. Cheer up, Watson, for I am very sure that our material has not yet all come to hand. When it does we may soon leave our difficulties behind us."

Little did I think how soon the words of Holmes would be realized, or how strange and sinister would be that new development which opened up an entirely fresh line of investigation.

I was shaving at my window in the morning when I heard the rattle of hoofs and, looking up, saw a dogcart coming at a gallop down the road. It pulled up at our door, and our friend, the vicar, sprang from it and rushed up our garden path. Holmes was already dressed, and we hastened down to meet him.

Our visitor was so excited that he could hardly articulate, but at last in gasps and bursts his tragic story came out of him. "We are devil-ridden, Mr. Holmes! My poor parish is devil-ridden!" he cried. "Satan himself is loose in it! We are given over into his hands!" He danced about in his agitation, a ludicrous object if it were not for his ashy face and startled eyes. Finally he shot out his terrible news. "Mr. Mortimer Tregennis died during the night, and with exactly the same symptoms as the rest of his family."