Mr. Sherlock Holmes was always of opinion that I should publish the singular facts connected with Professor Presbury, if only to dispel once for all the ugly rumours which some twenty years ago agitated the university and were echoed in the learned societies of London. There were, however, certain obstacles in the way, and the true history of this curious case remained entombed in the tin box which contains so many records of my friend’s adventures. Now we have at last obtained permission to ventilate the facts which formed one of the very last cases handled by Holmes before his retirement from practice. Even now a certain reticence and discretion have to be observed in laying the matter before the public.

It was one Sunday evening early in September of the year 1903 that I received one of Holmes’s laconic messages:

Come at once if convenient — if inconvenient come all the same. S. H.

The relations between us in those latter days were peculiar. He was a man of habits, narrow and concentrated habits, and I had become one of them. As an institution I was like the violin, the shag tobacco, the old black pipe, the index books, and others perhaps less excusable. When it was a case of active work and a comrade was needed upon whose nerve he could place some reliance, my role was obvious. But apart from this I had uses. I was a whetstone for his mind. I stimulated him. He liked to think aloud in my presence. His remarks could hardly be said to be made to me — many of them would have been as appropriately addressed to his bedstead — but none the less, having formed the habit, it had become in some way helpful that I should register and interject. If I irritated him by a certain methodical slowness in my mentality, that irritation served only to make his own flame-like intuitions and impressions flash up the more vividly and swiftly. Such was my humble role in our alliance.

When I arrived at Baker Street I found him huddled up in his armchair with updrawn knees, his pipe in his mouth and his brow furrowed with thought. It was clear that he was in the throes of some vexatious problem. With a wave of his hand he indicated my old armchair, but otherwise for half an hour he gave no sign that he was aware of my presence. Then with a start he seemed to come from his reverie, and with his usual whimsical smile he greeted me back to what had once been my home.

“You will excuse a certain abstraction of mind, my dear Watson,” said he. “Some curious facts have been submitted to me within the last twenty-four hours, and they in turn have given rise to some speculations of a more general character. I have serious thoughts of writing a small monograph upon the uses of dogs in the work of the detective.”

“But surely, Holmes, this has been explored,” said I. “Bloodhounds — sleuth-hounds —”

“No, no, Watson, that side of the matter is, of course, obvious. But there is another which is far more subtle. You may recollect that in the case which you, in your sensational way, coupled with the Copper Beeches, I was able, by watching the mind of the child, to form a deduction as to the criminal habits of the very smug and respectable father.”

“Yes, I remember it well.”

“My line of thoughts about dogs is analogous. A dog reflects the family life. Whoever saw a frisky dog in a gloomy family, or a sad dog in a happy one? Snarling people have snarling dogs, dangerous people have dangerous ones. And their passing moods may reflect the passing moods of others.”

I shook my head. “Surely, Holmes, this is a little far-fetched,” said I.

He had refilled his pipe and resumed his seat, taking no notice of my comment.

“The practical application of what I have said is very close to the problem which I am investigating. It is a tangled skein, you understand, and I am looking for a loose end. One possible loose end lies in the question: Why does Professor Presbury’s wolfhound, Roy, endeavour to bite him?”

I sank back in my chair in some disappointment. Was it for so trivial a question as this that I had been summoned from my work? Holmes glanced across at me.

“The same old Watson!” said he. “You never learn that the gravest issues may depend upon the smallest things. But is it not on the face of it strange that a staid, elderly philosopher — you’ve heard of Presbury, of course, the famous Camford physiologist? — that such a man, whose friend has been his devoted wolfhound, should now have been twice attacked by his own dog? What do you make of it?”

“The dog is ill.”

“Well, that has to be considered. But he attacks no one else, nor does he apparently molest his master, save on very special occasions. Curious, Watson — very curious. But young Mr. Bennett is before his time if that is his ring. I had hoped to have a longer chat with you before he came.”

There was a quick step on the stairs, a sharp tap at the door and a moment later the new client presented himself. He was a tall, handsome youth about thirty, well dressed and elegant, but with something in his bearing which suggested the shyness of the student rather than the self-possession of the man of the world. He shook hands with Holmes, and then looked with some surprise at me.

“This matter is very delicate, Mr. Holmes,” he said. “ Consider the relation in which I stand to Professor Presbury both privately and publicly. I really can hardly justify myself if I speak before any third person.”

“Have no fear, Mr. Bennett. Dr. Watson is the very soul of discretion, and I can assure you that this is a matter in which I am very likely to need an assistant.”

“As you like, Mr. Holmes. You will, I am sure, understand my having some reserves in the matter.”

“You will appreciate it, Watson, when I tell you that this gentleman, Mr. Trevor Bennett, is professional assistant to the great scientist, lives under his roof, and is engaged to his only daughter. Certainly we must agree that the professor has every claim upon his loyalty and devotion. But it may best be shown by taking the necessary steps to clear up this strange mystery.”

“I hope so, Mr. Holmes. That is my one object. Does Dr. Watson know the situation?”

“I have not had time to explain it.”

“Then perhaps I had better go over the ground again before explaining some fresh developments.”

“I will do so myself,” said Holmes, “in order to show that I have the events in their due order. The professor, Watson, is a man of European reputation. His life has been academic. There has never been a breath of scandal. He is a widower with one daughter, Edith. He is, I gather, a man of very virile and positive, one might almost say combative, character. So the matter stood until a very few months ago.

“Then the current of his life was broken. He is sixty-one years of age, but he became engaged to the daughter of Professor Morphy, his colleague in the chair of comparative anatomy. It was not, as I understand, the reasoned courting of an elderly man but rather the passionate frenzy of youth, for no one could have shown himself a more devoted lover. The lady, Alice Morphy, was a very perfect girl both in mind and body, so that there was every excuse for the professor’s infatuation. None the less, it did not meet with full approval in his own family.”

“We thought it rather excessive,” said our visitor.

“Exactly. Excessive and a little violent and unnatural. Professor Presbury was rich, however, and there was no objection upon the part of the father. The daughter, however, had other views, and there were already several candidates for her hand, who, if they were less eligible from a worldly point of view, were at least more of an age. The girl seemed to like the professor in spite of his eccentricities. It was only age which stood in the way.

“About this time a little mystery suddenly clouded the normal routine of the professor’s life. He did what he had never done before. He left home and gave no indication where he was going. He was away a fortnight and returned looking rather travel-worn. He made no allusion to where he had been, although he was usually the frankest of men. It chanced, however, that our client here, Mr. Bennett, received a letter from a fellow-student in Prague, who said that he was glad to have seen Professor Presbury there, although he had not been able to talk to him. Only in this way did his own household learn where he had been.

“Now comes the point. From that time onward a curious change came over the professor. He became furtive and sly. Those around him had always the feeling that he was not the man that they had known, but that he was under some shadow which had darkened his higher qualities. His intellect was not affected. His lectures were as brilliant as ever. But always there was something new, something sinister and unexpected. His daughter, who was devoted to him, tried again and again to resume the old relations and to penetrate this mask which her father seemed to have put on. You, sir, as I understand, did the same — but all was in vain. And now, Mr. Bennett, tell in your own words the incident of the letters.”

“You must understand, Dr. Watson, that the professor had no secrets from me. If I were his son or his younger brother I could not have more completely enjoyed his confidence. As his secretary I handled every paper which came to him, and I opened and subdivided his letters. Shortly after his return all this was changed. He told me that certain letters might come to him from London which would be marked by a cross under the stamp. These were to be set aside for his own eyes only. I may say that several of these did pass through my hands, that they had the E. C. mark, and were in an illiterate handwriting. If he answered them at all the answers did not pass through my hands nor into the letter-basket in which our correspondence was collected.”

“And the box,” said Holmes.

“Ah, yes, the box. The professor brought back a little wooden box from his travels. It was the one thing which suggested a Continental tour, for it was one of those quaint carved things which one associates with Germany. This he placed in his instrument cupboard. One day, in looking for a canula, I took up the box. To my surprise he was very angry, and reproved me in words which were quite savage for my curiosity. It was the first time such a thing had happened, and I was deeply hurt. I endeavoured to explain that it was a mere accident that I had touched the box, but all the evening I was conscious that he looked at me harshly and that the incident was rankling in his mind.” Mr. Bennett drew a little diary book from his pocket. “That was on July 2d,” said he.

“You are certainly an admirable witness,” said Holmes. “I may need some of these dates which you have noted.”

“I learned method among other things from my great teacher. From the time that I observed abnormality in his behaviour I felt that it was my duty to study his case. Thus I have it here that it was on that very day, July 2d, that Roy attacked the professor as he came from his study into the hall. Again, on July 11th, there was a scene of the same sort, and then I have a note of yet another upon July 20th. After that we had to banish Roy to the stables. He was a dear, affectionate animal — but I fear I weary you.”

Mr. Bennett spoke in a tone of reproach, for it was very clear that Holmes was not listening. His face was rigid and his eyes gazed abstractedly at the ceiling. With an effort he recovered himself.

“Singular! Most singular!” he murmured. “These details were new to me, Mr. Bennett. I think we have now fairly gone over the old ground, have we not? But you spoke of some fresh developments.”

The pleasant, open face of our visitor clouded over, shadowed by some grim remembrance. “What I speak of occurred the night before last,” said he. “I was lying awake about two in the morning, when I was aware of a dull muffled sound coming from the passage. I opened my door and peeped out. I should explain that the professor sleeps at the end of the passage —”

“The date being?” asked Holmes.

Our visitor was clearly annoyed at so irrelevant an interruption.

“I have said, sir, that it was the night before last — that is, September 4th.”

Holmes nodded and smiled.

“Pray continue,” said he.

“He sleeps at the end of the passage and would have to pass my door in order to reach the staircase. It was a really terrifying experience, Mr. Holmes. I think that I am as strong-nerved as my neighbours, but I was shaken by what I saw. The passage was dark save that one window halfway along it threw a patch of light. I could see that something was coming along the passage, something dark and crouching. Then suddenly it emerged into the light, and I saw that it was he. He was crawling, Mr. Holmes — crawling! He was not quite on his hands and knees. I should rather say on his hands and feet, with his face sunk between his hands. Yet he seemed to move with ease. I was so paralyzed by the sight that it was not until he had reached my door that I was able to step forward and ask if I could assist him. His answer was extraordinary. He sprang up, spat out some atrocious word at me, and hurried on past me, and down the staircase. I waited about for an hour, but he did not come back. It must have been daylight before he regained his room.”

“Well, Watson, what make you of that?” asked Holmes with the air of the pathologist who presents a rare specimen.

“Lumbago, possibly. I have known a severe attack make a man walk in just such a way, and nothing would be more trying to the temper.”

“Good, Watson! You always keep us flat-footed on the ground. But we can hardly accept lumbago, since he was able to stand erect in a moment.”

“He was never better in health,” said Bennett. “In fact, he is stronger than I have known him for years. But there are the facts, Mr. Holmes. It is not a case in which we can consult the police, and yet we are utterly at our wit’s end as to what to do, and we feel in some strange way that we are drifting towards disaster. Edith — Miss Presbury — feels as I do, that we cannot wait passively any longer.”

“It is certainly a very curious and suggestive case. What do you think, Watson?”

“Speaking as a medical man,” said I, “it appears to be a case for an alienist. The old gentleman’s cerebral processes were disturbed by the love affair. He made a journey abroad in the hope of breaking himself of the passion. His letters and the box may be connected with some other private transaction — a loan, perhaps, or share certificates, which are in the box.”

“And the wolfhound no doubt disapproved of the financial bargain. No, no, Watson, there is more in it than this. Now, I can only suggest —”

What Sherlock Holmes was about to suggest will never be known, for at this moment the door opened and a young lady was shown into the room. As she appeared Mr. Bennett sprang up with a cry and ran forward with his hands out to meet those which she had herself outstretched.

“Edith, dear! Nothing the matter, I hope?”

“I felt I must follow you. Oh, Jack, I have been so dreadfully frightened! It is awful to be there alone.”

“Mr. Holmes, this is the young lady I spoke of. This is my fiancee.”

“We were gradually coming to that conclusion, were we not, Watson?” Holmes answered with a smile. “I take it, Miss Presbury, that there is some fresh development in the case, and that you thought we should know?”

Our new visitor, a bright, handsome girl of a conventional English type, smiled back at Holmes as she seated herself beside Mr. Bennett.

“When I found Mr. Bennett had left his hotel I thought I should probably find him here. Of course, he had told me that he would consult you. But, oh, Mr. Holmes, can you do nothing for my poor father?”

“I have hopes, Miss Presbury, but the case is still obscure. Perhaps what you have to say may throw some fresh light upon it.”

“It was last night, Mr. Holmes. He had been very strange all day. I am sure that there are times when he has no recollection of what he does. He lives as in a strange dream. Yesterday was such a day. It was not my father with whom I lived. His outward shell was there, but it was not really he.”

“Tell me what happened.”

“I was awakened in the night by the dog barking most furiously. Poor Roy, he is chained now near the stable. I may say that I always sleep with my door locked; for, as Jack — as Mr. Bennett — will tell you, we all have a feeling of impending danger. My room is on the second floor. It happened that the blind was up in my window, and there was bright moonlight outside. As I lay with my eyes fixed upon the square of light, listening to the frenzied barkings of the dog, I was amazed to see my father’s face looking in at me. Mr. Holmes, I nearly died of surprise and horror. There it was pressed against the windowpane, and one hand seemed to be raised as if to push up the window. If that window had opened, I think I should have gone mad. It was no delusion, Mr. Holmes. Don’t deceive yourself by thinking so. I dare say it was twenty seconds or so that I lay paralyzed and watched the face. Then it vanished, but I could not — I could not spring out of bed and look out after it. I lay cold and shivering till morning. At breakfast he was sharp and fierce in manner, and made no allusion to the adventure of the night. Neither did I, but I gave an excuse for coming to town — and here I am.”

Holmes looked thoroughly surprised at Miss Presbury’s narrative.

“My dear young lady, you say that your room is on the second floor. Is there a long ladder in the garden?”

“No, Mr. Holmes, that is the amazing part of it. There is no possible way of reaching the window — and yet he was there.”

“The date being September 5th,” said Holmes. “That certainly complicates matters.”

It was the young lady’s turn to look surprised. “This is the second time that you have alluded to the date, Mr. Holmes,” said Bennett. “Is it possible that it has any bearing upon the case?”

“It is possible — very possible — and yet I have not my full material at present.”

“Possibly you are thinking of the connection between insanity and phases of the moon?”

“No, I assure you. It was quite a different line of thought. Possibly you can leave your notebook with me, and I will check the dates. Now I think, Watson, that our line of action is perfectly clear. This young lady has informed us — and I have the greatest confidence in her intuition — that her father remembers little or nothing which occurs upon certain dates. We will therefore call upon him as if he had given us an appointment upon such a date. He will put it down to his own lack of memory. Thus we will open our campaign by having a good close view of him.”

“That is excellent,” said Mr. Bennett. “I warn you, however, that the professor is irascible and violent at times.”

Holmes smiled. “There are reasons why we should come at once — very cogent reasons if my theories hold good. To-morrow, Mr. Bennett, will certainly see us in Camford. There is, if I remember right, an inn called the Chequers where the port used to be above mediocrity and the linen was above reproach. I think, Watson, that our lot for the next few days might lie in less pleasant places.”

Monday morning found us on our way to the famous university town — an easy effort on the part of Holmes, who had no roots to pull up, but one which involved frantic planning and hurrying on my part, as my practice was by this time not inconsiderable. Holmes made no allusion to the case until after we had deposited our suitcases at the ancient hostel of which he had spoken.

“I think, Watson, that we can catch the professor just before lunch. He lectures at eleven and should have an interval at home.”

“What possible excuse have we for calling?”

Holmes glanced at his notebook.

“There was a period of excitement upon August 26th. We will assume that he is a little hazy as to what he does at such times. If we insist that we are there by appointment I think he will hardly venture to contradict us. Have you the effrontery necessary to put it through?”

“We can but try.”

“Excellent, Watson! Compound of the Busy Bee and Excelsior. We can but try — the motto of the firm. A friendly native will surely guide us.”

Such a one on the back of a smart hansom swept us past a row of ancient colleges and, finally turning into a tree-lined drive, pulled up at the door of a charming house, girt round with lawns and covered with purple wistaria. Professor Presbury was certainly surrounded with every sign not only of comfort but of luxury. Even as we pulled up, a grizzled head appeared at the front window, and we were aware of a pair of keen eyes from under shaggy brows which surveyed us through large horn glasses. A moment later we were actually in his sanctum, and the mysterious scientist, whose vagaries had brought us from London, was standing before us. There was certainly no sign of eccentricity either in his manner or appearance, for he was a portly, large-featured man, grave, tall, and frock-coated, with the dignity of bearing which a lecturer needs. His eyes were his most remarkable feature, keen, observant, and clever to the verge ............