proved to be mad. No action is as yet possible."
"Then what on earth are we to do?"
"A little patience, Mr. Bennett. Things will soon develop. Unless I am mistaken next Tuesday may mark a crisis. Certainly we shall be in Camford on that day. Meanwhile, the general position is undeniably unpleasant, and if Miss Presbury can prolong her visit"
"That is easy."
"Then let her stay till we can assure her that all danger is past. Meanwhile, let him have his way and do not cross him. So long as he is in a good humour all is well."
"There he is!" said Bennett, in a startled whisper. Looking between the branches we saw the tall, erect figure emerge from the hall door and look around him. He stood leaning forward, his hands swinging straight before him, his head turning from side to side. The secretary with a last wave slipped off among the trees, and we saw him presently rejoin his employer, the two entering the house together in what seemed to be animated and even excited conversation.
"I expect the old gentleman has been putting two and two together," said Holmes, as we walked hotel-wards. "He struck me as having a particularly clear and logical brain, from the little I saw of him. Explosive, no doubt, but then from his point of view he has something to explode about if detectives are put on his track and he suspects his own household of doing it. I rather fancy that friend Bennett is in for an uncomfortable time."
Holmes stopped at a post office and sent off a telegram on our way. The answer reached us in the evening, and he tossed it across to me. "Have visited the Commercial Road and seen Dorak. Suave person, Bohemian, elderly. Keeps large general store.—Mercer."
"Mercer is since your time," said Holmes. "He is my general utility man who looks up routine business. It was important to know something of the man with whom our Professor was so secretly corresponding. His nationality connects up with the Prague visit."
"Thank goodness that something connects with something," said I. "At present we seem to be faced by a long series of inexplicable incidents with no bearing upon each other. For example what possible connection can there be between an angry wolf-hound and a visit to Bohemia, or either of them with a man crawling down a passage at night? As to your dates, that is the biggest mystification of all."
Holmes smiled and rubbed his hands. We were, I may say, seated in the old sitting-room of the ancient hotel, with a bottle of the famous vintage of which Holmes had spoken on the table between us.
"Well, now, let us take the dates first," said he, his fingertips together and his manner as if he were addressing a class. "This excellent young man's diary shows that there was trouble upon July 2nd, and from then onwards it seems to have been at nine-day intervals, with, so far as I remember, only one exception. Thus the last outbreak upon Friday was on September 3rd, which also falls into the series, as did August 25th, which preceded it. The thing is beyond coincidence."
I was forced to agree.
"Let us, then, form the provisional theory that every nine days the Professor takes some strong drug which has a passing but highly poisonous effect. His naturally violent nature is intensified by it. He learned to take this drug while he was in Prague, and is now supplied with it by a Bohemian intermediary in London. This all hangs together, Watson!"
"But the dog, the face at the window, the creeping man in the passage?"
"Well, well, we have made a beginning. I should not expect any fresh developments until next Tuesday. In the meantime we can only keep in touch with friend Bennett and enjoy the amenities of this charming town."
In the morning Mr. Bennett slipped round to bring us the latest report. As Holmes had imagined, times had not been easy with him. Without exactly accusing him of being responsible for our presence, the Professor had been very rough and rude in his speech, and evidently felt some strong grievance. This morning he was quite himself again, however, and had delivered his usual brilliant lecture to a crowded class. "Apart from his queer fits," said Bennett, "he has actually more energy and vitality than I can ever remember, nor was his brain ever clearer. But it's not he—it's never the man whom we have known."
"I don't think you have anything to fear now for a week at least," Holmes answered. "I am a busy man, and Dr. Watson has his patients to attend to. Let us agree that we meet here at this hour next Tuesday, and I shall be surprised if before we leave you again we are not able to explain, even if we cannot perhaps put an end to, your troubles. Meanwhile, keep us posted in what occurs."
I saw nothing of my friend for the next few days, but on the following Monday evening I had a short note asking me to meet him next day at the train. From
