Dr. Grimesby Roylott’s chamber was larger than that of his step-daughter, but was as plainly furnished. A camp-bed, a small wooden shelf full of books, mostly of a technical character, an armchair beside the bed, a plain wooden chair against the wall, a round table, and a large iron safe were the principal things which met the eye. Holmes walked slowly round and examined each and all of them with the keenest interest.

“What’s in here?” he asked, tapping the safe.

“My stepfather’s business papers.”

“Oh! you have seen inside, then?”

“Only once, some years ago. I remember that it was full of papers.”

“There isn’t a cat in it, for example?”

“No. What a strange idea!”

“Well, look at this!” He took up a small saucer of milk which stood on the top of it.

“No; we don’t keep a cat. But there is a cheetah and a baboon.”

“Ah, yes, of course! Well, a cheetah is just a big cat, and yet a saucer of milk does not go very far in satisfying its wants, I daresay. There is one point which I should wish to determine.” He squatted down in front of the wooden chair and examined the seat of it with the greatest attention.

“Thank you. That is quite settled,” said he, rising and putting his lens in his pocket. “Hullo! Here is something interesting!”

The object which had caught his eye was a small dog lash hung on one corner of the bed. The lash, however, was curled upon itself and tied so as to make a loop of whipcord.

“What do you make of that, Watson?”

“It’s a common enough lash. But I don’t know why it should be tied.”

“That is not quite so common, is it? Ah, me! it’s a wicked world, and when a clever man turns his brains to crime it is the worst of all. I think that I have seen enough now, Miss Stoner, and with your permission we shall walk out upon the lawn.”

I had never seen my friend’s face so grim or his brow so dark as it was when we turned from the scene of this investigation. We had walked several times up and down the lawn, neither Miss Stoner nor myself liking to break in upon his thoughts before he roused himself from his reverie.

“It is very essential, Miss Stoner,” said he, “that you should absolutely follow my advice in every respect.”

“I shall most certainly do so.”

“The matter is too serious for any hesitation. Your life may depend upon your compliance.”

“I assure you that I am in your hands.”

“In the first place, both my friend and I must spend the night in your room.”

Both Miss Stoner and I gazed at him in astonishment.

“Yes, it must be so. Let me explain. I believe that that is the village inn over there?”

“Yes, that is the Crown.”

“Very good. Your windows would be visible from there?”

“Certainly.”

“You must confine yourself to your room, on pretence of a headache, when your stepfather comes back. Then when you hear him retire for the night, you must open the shutters of your window, undo the hasp, put your lamp there as a signal to us, and then withdraw quietly with everything which you are likely to want into the room which you used to occupy. I have no doubt that, in spite of the repairs, you could manage there for one night.”

“Oh, yes, easily.”

“The rest you will leave in our hands.”

“But what will you do?”

“We shall spend the night in your room, and we shall investigate the cause of this noise which has disturbed you.”

“I believe, Mr. Holmes, that you have already made up your mind,” said Miss Stoner, laying her hand upon my companion’s sleeve.

“Perhaps I have.”

“Then, for pity’s sake, tell me what was the cause of my sister’s death.”

“I should prefer to have clearer proofs before I speak.”

“You can at least tell me whether my own thought is correct, and if she died from some sudden fright.”

“No, I do not think so. I think that there was probably some more tangible cause. And now, Miss Stoner, we must leave you for if Dr. Roylott returned and saw us our journey would be in vain. Good-bye, and be brave, for if you will do what I have told you, you may rest assured that we shall soon drive away the dangers that threaten you.”

Sherlock Holmes and I had no difficulty in engaging a bedroom and sitting-room at the Crown Inn. They were on the upper floor, and from our window we could command a view of the avenue gate, and of the inhabited wing of Stoke Moran Manor House. At dusk we saw Dr. Grimesby Roylott drive past, his huge form looming up beside the little figure of the lad who drove him. The boy had some slight difficulty in undoing the heavy iron gates, and we heard the hoarse roar of the doctor’s voice and saw the fury with which he shook his clinched fists at him. The trap drove on, and a few minutes later we saw a sudden light spring up among the trees as the lamp was lit in one of the sitting-rooms.

“Do you know, Watson,” said Holmes as we sat together in the gathering darkness, “I have really some scruples as to taking you to-night. There is a distinct element of danger.”

“Can I be of assistance?”

“Your presence might be invaluable.”

“Then I shall certainly come.”

“It is very kind of you.”

“You speak of danger. You have evidently seen more in these rooms than was visible to me.”

“No, but I fancy that I may have deduced a little more. I imagine that you saw all that I did.”

“I saw nothing remarkable save the bell-rope, and what purpose that could answer I confess is more than I can imagine.”

“You saw the ventilator, too?”

“Yes, but I do not think that it is such a very unusual thing to have a small opening between two rooms. It was so small that a rat could hardly pass through.”

“I knew that we should find a ventilator before ever we came to Stoke Moran.”

“My dear Holmes!”

“Oh, yes, I did. You remember in her statement she said that her sister could smell Dr. Roylott’s cigar. Now, of course that suggested at once that there must be a communication between the two rooms. It could only be a small one, or it would have been remarked upon at the coroner’s inquiry. I deduced a ventilator.”

“But what harm can there be in that?”

“Well, there is at least a curious coincidence of dates. A ventilator is made, a cord is hung, and a lady who sleeps in the bed dies. Does not that strike you?”

“I cannot as yet see any connection.”

“Did you observe anything very peculiar about that bed?”

“No.”

“It was clamped to the floor. Did you ever see a bed fastened like that before?”

“I cannot say that I have.”

“The lady could not move her bed. It must always be in the same relative position to the ventilator and to the rope—or so we may call it, since it was clearly never meant for a bell-pull.”

“Holmes,” I cried, “I seem to see dimly what you are hinting at. We are only just in time to prevent some subtle and horrible crime.”

“Subtle enough and horrible enough. When a doctor does go wrong he is the first of criminals. He has nerve and he has knowledge. Palmer and Pritchard were among the heads of their profession. This man strikes even deeper, but I think, Watson, that we shall be able to strike deeper still. But we shall have horrors enough before the night is over; for goodness’ sake let us have a quiet pipe and turn our minds for a few hours to something more cheerful.”

About nine o’clock the light among the trees was extinguished, and all was dark in the direction of the Manor House. Two hours passed slowly away, and then, suddenly, just at the stroke of eleven, a single bright light shone out right in front of us.

“That is our signal,” said Holmes, springing to his feet; “it comes from the middle window.”

As we passed out he exchanged a few words with the landlord, explaining that we were going on a late visit to an acquaintance, and that it was possible that we might spend the night there. A moment later we were out on the dark road, a chill wind blowing in our faces, and one yellow light twinkling in front of us through the gloom to guide us on our sombre errand.

There was little difficulty in entering the grounds, for unrepaired breaches gaped in the old park wall. Making our way among the trees, we reached the lawn, crossed it, and were about to enter through the window when out from a clump of laurel bushes there darted what seemed to be a hideous and distorted child, who threw itself upon the grass with writhing limbs and then ran swiftly across the lawn into the darkness.

“My God!” I whispered; “did you see it?”

Holmes was for the moment as startled as I. His hand closed like a vice upon my wrist in his agitation. Then he broke into a low laugh and put his lips to my ear.

“It is a nice household,” he murmured. “That is the baboon.”

I had forgotten the strange pets which the doctor affected. There was a cheetah, too; perhaps we might find it upon our shoulders at any moment. I confess that I felt easier in my mind when, after following Holmes’ example and slipping off my shoes, I found myself inside the bedroom. My companion noiselessly closed the shutters, moved the lamp onto the table, and cast his eyes round the room. All was as we had seen it in the daytime. Then creeping up to me and making a trumpet of his hand, he whispered into my ear again so gently that it was all that I could do to distinguish the words:

“The least sound would be fatal to our plans.”

I nodded to show that I had heard.

“We must sit without light. He would see it through the ventilator.”

I nodded again.

“Do not go asleep; your very life may depend upon it. Have your pistol ready in case we should need it. I will sit on the side of the bed, and you in that chair.”

I took out my revolver and laid it on the corner of the table.

Holmes had brought up a long thin cane, and this he placed upon the bed beside him. By it he laid the box of matches and the stump of a candle. Then he turned down the lamp, and we were left in darkness.

How shall I ever forget that dreadful vigil? I could not hear a sound, not even the drawing of a breath, and yet I knew that my companion sat open-eyed, within a few feet of me, in the same state of nervous tension in which I was myself. The shutters cut off the least ray of light, and we waited in absolute darkness.

From outside came the occasional cry of a night-bird, and once at our very window a long drawn catlike whine, which told us that the cheetah was indeed at liberty. Far away we could hear the deep tones of the parish clock, which boomed out every quarter of an hour. How long they seemed, those quarters! Twelve struck, and one and two and three, and still we sat waiting silently for whatever might befall.

Suddenly there was the momentary gleam of a light up in the direction of the ventilator, which vanished immediately, but was succeeded by a strong smell of burning oil and heated metal. Someone in the next room had lit a dark-lantern. I heard a gentle sound of movement, and then all was silent once more, though the smell grew stronger. For half an hour I sat with straining ears. Then suddenly another sound became audible—a very gentle, soothing sound, like that of a small jet of steam escaping continually from a kettle. The instant that we heard it, Holmes sprang from the bed, struck a match, and lashed furiously with his cane at the bell-pull.

“You see it, Watson?” he yelled. “You see it?”

But I saw nothing. At the moment when Holmes struck the light I heard a low, clear whistle, but the sudden glare flashing into my weary eyes made it impossible for me to tell what it was at which my friend lashed so savagely. I could, however, see that his face was deadly pale and filled with horror and loathing. He had ceased to strike and was gazing up at the ventilator when suddenly there broke from the silence of the night the most horrible cry to which I have ever listened. It swelled up louder and louder, a hoarse yell of pain and fear and anger all mingled in the one dreadful shriek. They say that away down in the village, and even in the distant parsonage, that cry raised the sleepers from their beds. It struck cold to our hearts, and I stood gazing at Holmes, and he at me, until the last echoes of it had died away into the silence from which it rose.

“What can it mean?” I gasped.

“It means that it is all over,” Holmes answered. “And perhaps, after all, it is for the best. Take your pistol, and we will enter Dr. Roylott’s room.”

With a grave face he lit the lamp and led the way down the corridor. Twice he struck at the chamber door without any reply from within. Then he turned the handle and entered, I at his heels, with the cocked pistol in my hand.

It was a singular sight which met our eyes. On the table stood a dark-lantern with the shutter half open, throwing a brilliant beam of light upon the iron safe, the door of which was ajar. Beside this table, on the wooden chair, sat Dr. Grimesby Roylott clad in a long grey dressing-gown, his bare ankles protruding beneath, and his feet thrust into red heelless Turkish slippers. Across his lap lay the short stock with the long lash which we had noticed during the day. His chin was cocked upward and his eyes were fixed in a dreadful, rigid stare at the corner of the ceiling. Round his brow he had a peculiar yellow band, with brownish speckles, which seemed to be bound tightly round his head. As we entered he made neither sound nor motion.

“The band! the speckled band!” whispered Holmes.

I took a step forward. In an instant his strange headgear began to move, and there reared itself from among his hair the squat diamond-shaped head and puffed neck of a loathsome serpent.

“It is a swamp adder!” cried Holmes; “the deadliest snake in India. He has died within ten seconds of being bitten. Violence does, in truth, recoil upon the violent, and the schemer falls into the pit which he digs for another. Let us thrust this creature back into its den, and we can then remove Miss Stoner to some place of shelter and let the county police know what has happened.”

As he spoke he drew the dog-whip swiftly from the dead man’s lap, and throwing the noose round the reptile’s neck he drew it from its horrid perch and, carrying it at arm’s length, threw it into the iron safe, which he closed upon it.

Such are the true facts of the death of Dr. Grimesby Roylott, of Stoke Moran. It is not necessary that I should prolong a narrative which has already run to too great a length by telling how we broke the sad news to the terrified girl, how we conveyed her by the morning train to the care of her good aunt at Harrow, of how the slow process of official inquiry came to the conclusion that the doctor met his fate while indiscreetly playing with a dangerous pet. The little which I had yet to learn of the case was told me by Sherlock Holmes as we travelled back next day.

“I had,” said he, “come to an entirely erroneous conclusion which shows, my dear Watson, how dangerous it always is to reason from insufficient data. The presence of the gipsies, and the use of the word ‘band,’ which was used by the poor girl, no doubt, to explain the appearance which she had caught a hurried glimpse of by the light of her match, were sufficient to put me upon an entirely wrong scent. I can only claim the merit that I instantly reconsidered my position when, however, it became clear to me that whatever danger threatened an occupant of the room could not come either from the window or the door. My attention was speedily drawn, as I have already remarked to you, to this ventilator, and to the bell-rope which hung down to the bed. The discovery that this was a dummy, and that the bed was clamped to the floor, instantly gave rise to the suspicion that the rope was there as a bridge for something passing through the hole and coming to the bed. The idea of a snake instantly occurred to me, and when I coupled it with my knowledge that the doctor was furnished with a supply of creatures from India, I felt that I was probably on the right track. The idea of using a form of poison which could not possibly be discovered by any chemical test was just such a one as would occur to a clever and ruthless man who had had an Eastern training. The rapidity with which such a poison would take effect would also, from his point of view, be an advantage. It would be a sharp-eyed coroner, indeed, who could distinguish the two little dark punctures which would show where the poison fangs had done their work. Then I thought of the whistle. Of course he must recall the snake before the morning light revealed it to the victim. He had trained it, probably by the use of the milk which we saw, to return to him when summoned. He would put it through this ventilator at the hour that he thought best, with the certainty that it would crawl down the rope and land on the bed. It might or might not bite the occupant, perhaps she might escape every night for a week, but sooner or later she must fall a victim.

“I had come to these conclusions before ever I had entered his room. An inspection of his chair showed me that he had been in the habit of standing on it, which of course would be necessary in order that he should reach the ventilator. The sight of the safe, the saucer of milk, and the loop of whipcord were enough to finally dispel any doubts which may have remained. The metallic clang heard by Miss Stoner was obviously caused by her stepfather hastily closing the door of his safe upon its terrible occupant. Having once made up my mind, you know the steps which I took in order to put the matter to the proof. I heard the creature hiss as I have no doubt that you did also, and I instantly lit the light and attacked it.”

“With the result of driving it through the ventilator.”

“And also with the result of causing it to turn upon its master at the other side. Some of the blows of my cane came home and roused its snakish temper, so that it flew upon the first person it saw. In this way I am no doubt indirectly responsible for Dr. Grimesby Roylott’s death, and I cannot say that it is likely to weigh very heavily upon my conscience.”