“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 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.”

"Perhaps I'm in the way?" Lupin suggested.

"Not at all, doctor, not at all," said Daubrecq. "Besides, what I have to say has a certain bearing on your errand." And, into the telephone, "Hullo! M. Prasville?... Ah, it's you, Prasville, old cock!... Why, you seem quite staggered! Yes, you're right, it's an age since you and I met. But, after all, we've never been far away in thought... And I've had plenty of visits from you and your henchmen... In my absence, it's true. Hullo!... What?... Oh, you're in a hurry? I beg your pardon!... So am I, for that matter... Well, to come to the point, there's a little service I want to do you... Wait, can't you, you brute?... You won't regret it... It concerns your renown... Hullo!... Are you listening?... Well, take half-a-dozen men with you... plain-clothes detectives, by preference: you'll find them at the night-office... Jump into a taxi, two taxis, and come along here as fast as you can... I've got a rare quarry for you, old chap. One of the upper ten... a lord, a marquis Napoleon himself... in a word, Arsene Lupin!"

Lupin sprang to his feet. He was prepared for everything but this. Yet something within him stronger than astonishment, an impulse of his whole nature, made him say, with a laugh:

"Oh, well done, well done!"

Daubrecq bowed his head, by way of thanks, and muttered:

"I haven't quite finished... A little patience, if you don't mind." And he continued, "Hullo! Prasville!... No, no, old chap, I'm not humbugging... You'll find Lupin here, with me, in my study... Lupin, who's worrying me like the rest of you... Oh, one more or less makes no difference to me! But, all the same, this one's a bit too pushing. And I am appealing to your sense of kindness. Rid me of the fellow, do... Half-a-dozen of your satellites and the two who are pacing up and down outside my house will be enough... Oh, while you're about it, go up to the third floor and rope in my cook as well... She's the famous Victoire: you know, Master Lupin's old nurse... And, look here, one more tip, to show you how I love you: send a squad of men to the Rue Chateaubriand, at the corner of the Rue Balzac... That's where our national hero lives, under the name of Michel Beaumont... Do you twig, old cockalorum? And now to business. Hustle!"

When Daubrecq turned his head, Lupin was standing up, with clenched fists. His burst of admiration had not survived the rest of the speech and the revelations which Daubrecq had made about Victoire and the flat in the Rue Chateaubriand. The humiliation was too great; and Lupin no longer bothered to play the part of the small general practitioner. He had but one idea in his head: not to give way to the tremendous fit of rage that was urging him to rush at Daubrecq like a bull.

Daubrecq gave the sort of little cluck which, with him, did duty for a laugh. He came waddling up, with his hands in his trouser-pockets, and said, incisively:

"Don't you think that this is all for the best? I've cleared the ground, relieved the situation... At least, we now know where we stand. Lupin versus Daubrecq; and that's all about it. Besides, think of the time saved! Dr. Vernes, the divisional surgeon, would have taken two hours to spin his yarn! Whereas, like this, Master Lupin will be compelled to get his little story told in thirty minutes... unless he wants to get himself collared and his accomplices nabbed. What a shock! What a bolt from the blue! Thirty minutes and not a minute more. In thirty minutes from now, you'll have to clear out, scud away like a hare and beat a disordered retreat. Ha, ha, ha, what fun! I say, Polonius, you really are unlucky, each time you come up against Bibi Daubrecq! For it was you who were hiding behind that curtain, wasn't it, my ill-starred Polonius?"