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 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.”

"Shall I tell you what is happening, monsieur le secretaire-general? Well, you too are having your head turned by all this business Now that you possess the list, your state of mind has suddenly sunk to that of a Daubrecq or a d'Albufex. There is no longer even a question, in your thoughts, of taking it to your superiors, so that this ferment of disgrace and discord may be ended. No, no; a sodden temptation has seized upon you and intoxicated you; and, losing your head, you say to yourself, 'It is here, in my pocket. With its aid, I am omnipotent. It means wealth, absolute, unbounded power. Why not benefit by it? Why not let Gi1hert and Clarisse Mergy die? Why not lock up that idiot of a Lupin? Why not seize this unparalleled piece of fortune by the forelock?"'

He bent toward Prasville and, very softly, in a friendly and confidential tone, said:

"Don't do that, my dear sir, don't do it."

"And why not?"

"It is not to your interest, believe me."

"Really!"

"No. Or, if you absolutely insist on doing it, have the kindness first to consult the twenty-seven names on the list of which you have just robbed me and reflect, for a moment, on the name of the third person on it."

"Oh? And what is the name of that third person?"

"It is the name of a friend of yours."

"What friend?

"Stanislas Vorenglade, the ex-deputy."

"And then?" said Prasville, who seemed to be losing some of his self-confidence.

"Then? Ask yourself if an inquiry, however summary, would not end by discovering, behind that Stanislas Vorenglade, the name of one who shared certain little profits with him."

"And whose name is?"

"Louis Prasville."

M. Nicole banged the table with his fist.

"Enough of this humbug, monsieur! For twenty minutes, you and I have been beating about the bush. That will do. Let us understand each other. And, to begin with, drop your pistols. You can't imagine that I am frightened of those playthings! Stand up, sir, stand up, as I am doing, and finish the business: I am in a hurry."

He put his hand on Prasville's shoulder and, speaking with great deliberation, said:

"If, within an hour from now, you are not back from the Elysee, bringing with you a line to say that the decree of pardon has been signed; if, within one hour and ten minutes, I, Arsene Lupin, do not walk out of this building safe and sound and absolutely free, this evening four Paris newspapers will receive four letters selected from the correspondence exchanged between Stanislas Vorenglade and yourself, the correspondence which Stanislas Vorenglade sold me this morning. Here's your hat, here's your overcoat, here's your stick. Be off. I will wait for you."

Then happened this extraordinary and yet easily understood thing, that Prasville did not raise the slightest protest nor make the least show of fight. He received the sudden, far-reaching, utter conviction of what the personality known as Arsene Lupin meant, in all its breadth and fulness. He did not so much as think of carping, of pretending - as he had until then believed - that the letters had been destroyed by Vorenglade the deputy or, at any rate, that Vorenglade would not dare to hand them over, because, in so doing, Vorenglade was also working his own destruction. No, Prasville did not speak a word He felt himsell caught in a vise of which no human strength could force the jaws asunder. There was nothing to do but yield. He yielded.