“Before I could utter more, my visitor said, ‘It is in there. I can sense it. You may close the door now, Miss Stoner, and pray lock it and leave it locked no matter what sounds you may hear from within.’
“As I locked the door, and I will say I was greatly relieved to do so, I asked, ‘What do you intend to do now?’
“Said he, ‘I will be taking the earliest train back to London.’
“‘London?’ I exclaimed. ‘But you said you meant to deal with this situation somehow, Mr Thurn.’
“He said, ‘And so is it my intention, but I must be alone and undisturbed. I created these tulpas at a great remove, and at a remove I will destroy the last of them, but it will require the greatest concentration. It is perhaps even more difficult to unmake a tulpa than to make one. You see how they persisted even if only in a declining state after the death of your stepfather, though deprived of his belief in them? Even before his death they had taken on life of their own. I must have that life back. It will be no small effort.’ Here he affected a smile, but it was a horrid mockery of such an expression. He said, ‘To think that I studied and strived all these years, only to create weapons for a murderer.’
“‘Is there nothing I can do?’ I asked him.
“‘If it is possible,’ he replied, ‘you must focus on the knowledge that this creature is not a flesh and blood entity. It is an illusion, and you would do best to hold onto that thought with all your power, for surely the creature has been feeding off your own belief all this time, as well.’
“Mr Thurn bid me good afternoon then, and the last I saw of him he was walking off in the direction of the Crown Inn, so as to get a dog-cart to take him to Leatherhead, where he would take a train to London.
“You will not be surprised when I say I did not sleep that night as I lay wondering if I had entertained a madman in my home that day. And yet, almost against my will, I could not entirely dismiss what he had told me as absolute fancy. I suppose madmen are earnest in their madness, but this gentleman seemed entirely lucid to me. Looking into his too-keen eyes was much like looking into your own, Mr Holmes.
“In any case, at about half past two in the morning my restlessness caused me at last to rise from my bed, take up my lantern and venture from my chamber, stepping quietly so as not to disturb Mrs Littledale next door. I was drawn to the locked door leading to the abandoned wing of the house. I do not know quite why, but it was as though I had sleepwalked there; that is to say, it did not seem a conscious decision. I feel now that I was acting on an intuition.
“I leaned my head close to the panel but heard nothing beyond, even when I laid my ear against the wood. One might think I would then have gone back to my bedroom, and yet my compulsion had not been satisfied. I had brought the key with me as before, and again I unlocked the door and opened it while shining my lantern into the dreadful blackness beyond.
“Oh that I had not done so, Mr Holmes, because I will never forget the sight that lay before me. I dare say I would not have needed my lantern to see into that long, dark passage, because the two figures situated in its centre seemed to radiate a soft, pale glow much as though bathed in moonlight. There on the floor of the hallway lay the cheetah, though I would not have recognised it as such had I not known what it was. Otherwise, I might easily have taken it for the skeleton of a large dog, impossibly imbued with life. It lay on its side, so wasted that it was a wonder it was able to raise its head. But its head was indeed raised, as it glared with a palpable malice at the man who stood over it only a few paces away.
“That man was Mr Edward Thurn. I am embarrassed to tell you that he was without clothing, his skin appearing almost radiantly white as I have described. He was returning the animal’s gaze, but he had obviously heard me open the door and from the corner of his eye seen the glare of my lantern, for without taking his eyes off the creature he raised his left arm and pointed his finger at me. I understood what he signified by this gesture. He was commanding me to withdraw and close the door. This I did, and when I had turned the key in the lock I backed away from the door with the whole of my body shaking, for I had never in my life witnessed so ghastly a scene but for having watched my dear twin die before my very eyes. I returned to my room then and sat upon my bed, still shaking, until dawn. Only then could I summon the courage to return to the locked door and crack it open sufficiently to peer beyond. This time there was nothing to see but shadows. I experienced another intuition, and that was a certainty that the cheetah was gone forever.”
At this point in my narrative Mr Holmes asked, “Might this nocturnal excursion have only been a dream, Miss Stoner? For I am sorry to report that your visitor Edward Thurn is no longer among the living.”
“What’s this, Holmes?” Dr Watson said, quite surprised.
“Really, Watson,” Mr Holmes said to him, “you must pay closer attention to the morning paper.” Here he gestured to a folded copy of that morning’s Daily Telegraph that rested nearby. “I knew the name as soon as you uttered it, Miss Stoner, but I wanted to hear your story in full before I admitted as much. Yet I suspect you are already aware of the man’s fate, for you have just now come from the place where he had taken a room in Upper Swandam Lane, have you not?”
“You guess correctly, Mr Holmes,” said I.
“I do not guess, Miss Stoner. I deduce. Your breathlessness when you entered this room and your agitated comportment indicated a very recent shock.”
“I did not realise his death had already been reported in the paper. This morning when I inquired about Mr Thurn at the address given on the letter he had sent to my stepfather I was told there had been a terrifying cry from his room at about three in the morning, and when the door was finally forced Mr Thurn was found lying dead on the bed, his eyes staring fixedly into nothingness. It was the opinion of those who saw him that his heart had given out.”
“The cause given in the paper was apoplexy,” Mr Holmes stated. “But surely you see the dilemma here, Miss Stoner. The body of the obscure explorer and world traveller Edward Thurn was discovered at three in the morning, but you claim to have seen him standing in your very home at approximately half past two. It is impossible for him to have arrived back in London in so short a time.”
“Precisely, Mr Holmes. It would be an impossibility under natural circumstances.”
“Then I will propose supernatural circumstances, in keeping with your account. That it was not actually Mr Thurn you saw, but some projected essence of himself that he sent to deal with that other phantom being.”
“Make of it what you will, Mr Holmes. It is all beyond me.”
He clicked his pipe stem against his teeth, then pondered aloud, “Of course there is no such thing as a swamp adder. What was I thinking?”
“With all respect to Miss Stoner, whose own trustworthiness I do not doubt,” Dr Watson said to his friend, “if one were to entertain for even a moment such outrageous notions, surely a man as hateful as Grimesby Roylott would not be capable of the mental feats this Thurn fellow claimed were required for their collaboration.”
Lowering his pipe, Mr Holmes replied, “But Roylott was, in some ways, well suited to such an exercise, being that he felt he answered to no man or God, and that his mental acuity entitled him to power. There is no richer soil for the growth of evil than the supposition that one is superior to one’s fellow human beings. Mind, there are those who, being cognisant of their greater-than-average intelligence, will utilise it for the betterment of others as if it were a resource they had received in unfair quantity. But too many hoard their intelligence, and allow it to deform their self-conception into something superhuman, when in fact ‘inhuman’ would be the better designation. Unfortunately, Roylott was not a singular specimen; this world teems with his ilk.”