"Yes, the portress caught Victoire listening to Daubrecq's conversation with me on the telephone; and the Masher, who was watching the house, saw you go out. I suspected, therefore, that you would follow Daubrecq that evening."

"And the woman who came here, late one afternoon ... "

"Was myself. I felt disheartened and wanted to see you."

"And you intercepted Gilbert's letter?"

"Yes, I recognized his writing on the envelope."

"But your little Jacques was not with you?"

"No, he was outside, in a motor-car, with the Masher, who lifted him up to me through the drawing-room window; and he slipped into your bedroom through the opening in the panel."

"What was in the letter?"

"As ill-luck would have it, reproaches. Gilbert accused you of forsaking him, of taking over the business on your own account. In short, it confirmed me in my distrust; and I ran away."

Lupin shrugged his shoulders with irritation:

"What a shocking waste of time! And what a fatality that we were not able to come to an understanding earlier! You and I have been playing at hide-and-seek, laying absurd traps for each other, while the days were passing, precious days beyond repair."

"You see, you see," she said, shivering, "you too are afraid of the future!"

"No, I am not afraid," cried Lupin. "But Reference I am thinking of all the useful work that we could have done by this time, if we had united our efforts. I am thinldng of all the mistakes and all the acts of imprudence which we should have been saved, if we had been working together. I am thinking that your attempt to-night to search the clothes which Daubrecq was wearing was as vain as the others and that, at this moment, thanks to our foolish duel, thanks to the din which we raised in his house, Daubrecq is warned and will be more on his guard than ever."

Clarisse Mergy shook her head:

"No, no, I don't think that; the noise will not have roused him, for we postponed the attempt for twenty-four hours so that the portress might put a narcotic in his wine." And she added, slowly, "And then, you see, nothing can make Daubrecq be more on his guard than he is already. His life is nothing but one mass of precautions against danger. He leaves nothing to chance... Besides, has he not all the trumps in his hand?"

Lupin went up to her and asked:

"What do you mean to convey? According to you, is there nothing to hope for on that side? Is there not a single means of attaining our end?"

"Yes," she murmured, "there is one, one only... "

He noticed her pallor before she had time to hide her face between her hands again. And again a feverish shiver shook her frame.

He seemed to understand the reason of her dismay; and, bending toward her, touched by her grief:

"Please," he said, "please answer me openly and frankly. It's for Gilbert's sake, is it not? Though the police, fortunately, have not been able to solve the riddle of his past, though the real name of Vaucheray's accomplice has not Leaked out, there is one man, at least, who knows it: isn't that so? Daubrecq has recognized your son Antoine, through the alias of Gilbert, has he not?"

And then in a moment it happened! It was not the chain that broke, but it was the collar that slipped, for it had been made for a thick-necked Newfoundland. We heard the rattle of falling metal, and the next instant dog and man were rolling on the ground together, the one roaring in rage, the other screaming in a strange shrill falsetto of terror. It was a very narrow thing for the professor’s life. The savage creature had him fairly by the throat, its fangs had bitten deep, and he was senseless before we could reach them and drag the two apart. It might have been a dangerous task for us, but Bennett’s voice and presence brought the great wolf-hound instantly to reason. The uproar had brought the sleepy and astonished coachman from his room above the stables. “I’m not surprised,” said he, shaking his head. “I’ve seen him at it before. I knew the dog would get him sooner or later.”

The hound was secured, and together we carried the professor up to his room, where Bennett, who had a medical degree, helped me to dress his torn throat. The sharp teeth had passed dangerously near the carotid artery, and the haemorrhage was serious. In half an hour the danger was past, I had given the patient an injection of morphia, and he had sunk into deep sleep. Then, and only then, were we able to look at each other and to take stock of the situation.

“I think a first-class surgeon should see him,” said I.

“For God’s sake, no!” cried Bennett. “At present the scandal is confined to our own household. It is safe with us. If it gets beyond these walls it will never stop. Consider his position at the university, his European reputation, the feelings of his daughter.”

“Quite so,” said Holmes. “I think it may be quite possible to keep the matter to ourselves, and also to prevent its recurrence now that we have a free hand. The key from the watch-chain, Mr. Bennett. Macphail will guard the patient and let us know if there is any change. Let us see what we can find in the professor’s mysterious box.”

There was not much, but there was enough — an empty phial, another nearly full, a hypodermic syringe, several letters in a crabbed, foreign hand. The marks on the envelopes showed that they were those which had disturbed the routine of the secretary, and each was dated from the Commercial Road and signed “A. Dorak.” They were mere invoices to say that a fresh bottle was being sent to Professor Presbury, or receipt to acknowledge money. There was one other envelope, however, in a more educated hand and bearing the Austrian stamp with the postmark of Prague. “Here we have our material!” cried Holmes as he tore out the enclosure.

HONOURED COLLEAGUE [it ran]:

Since your esteemed visit I have thought much of your case, and though in your circumstances there are some special reasons for the treatment, I would none the less enjoin caution, as my results have shown that it is not without danger of a kind.