"Monsieur Destange may or may not be at home. That depends. Has monsieur a card?"
Monsieur did not have a card, but he had a letter of introduction and, after the servant had taken the letter to Mon. Destange, he was conducted into the presence of that gentleman who was sitting in a large circular room or rotunda which occupied one of the wings of the house. It was a library, and contained a profusion of books and architectural drawings. When the stranger entered, the architect said to him:
"You are Monsieur Stickmann?"
"Yes, monsieur."
"My secretary tells me that he is ill, and has sent you to continue the general catalogue of the books which he commenced under my direction, and, more particularly, the catalogue of German books. Are you familiar with that kind of work?"
"Yes, monsieur, quite so," he replied, with a strong German accent.
Under those circumstances the bargain was soon concluded, and Mon. Destange commenced work with his new secretary.
Herlock Sholmes had gained access to the house.
In order to escape the vigilance of Arsène Lupin and gain admittance to the house occupied by Lucien Destange and his daughter Clotilde, the famous detective had been compelled to resort to a number of stratagems, and, under a variety of names, to ingratiate himself into the good graces and confidence of a number of persons—in short, to live, during forty-eight hours, a most complicated life. During that time he had acquired the following information: Mon. Destange, having retired from active business on account of his failing health, now lived amongst the many books he had accumulated on the subject of architecture. He derived infinite pleasure in viewing and handling those dusty old volumes.
His daughter Clotilde was considered eccentric. She passed her time in another part of the house, and never went out.
"Of course," Sholmes said to himself, as he wrote in a register the titles of the books which Mon. Destange dictated to him, "all that is vague and incomplete, but it is quite a long step in advance. I shall surely solve one of these absorbing problems: Is Mon. Destange associated with Arsène Lupin? Does he continue to see him? Are the papers relating to the construction of the three houses still in existence? Will those papers not furnish me with the location of other houses of similar construction which Arsène Lupin and his associates will plunder in the future?
"Monsieur Destange, an accomplice of Arsène Lupin! That venerable man, an officer of the Legion of Honor, working in league with a burglar—such an idea was absurd! Besides, if we concede that such a complicity exists, how could Mon. Destange, thirty years ago, have possibly foreseen the thefts of Arsène Lupin, who was then an infant?"
No matter! The Englishman was implacable. With his marvellous scent, and that instinct which never fails him, he felt that he was in the heart of some strange mystery. Ever since he first entered the house, he had been under the influence of that impression, and yet he could not define the grounds on which he based his suspicions.
Up to the morning of the second day he had not made any significant discovery. At two o'clock of that day he saw Clotilde Destange for the first time; she came to the library in search of a book. She was about thirty years of age, a brunette, slow and silent in her movements, with features imbued with that expression of indifference which is characteristic of people who live a secluded life. She exchanged a few words with her father, and then retired, without even looking at Sholmes.
The afternoon dragged along monotonously. At five o'clock Mon. Destange announced his intention to go out. Sholmes was alone on the circular gallery that was constructed about ten feet above the floor of the rotunda. It was almost dark. He was on the point of going out, when he heard a slight sound and, at the same time, experienced the feeling that there was someone in the room. Several minutes passed before he saw or heard anything more. Then he shuddered; a shadowy form emerged from the gloom, quite close to him, upon the balcony. It seemed incredible. How long had this mysterious visitor been there? Whence did he come?
The strange man descended the steps and went directly to a large oaken cupboard. Sholmes was a keen observer of the man's movements. He watched him searching amongst the papers with which the cupboard was filled. What was he looking for?
Then the door opened and Mlle. Destange entered, speaking to someone who was following her:
"So you have decided not to go out, father?... Then I will make a light ... one second ... do not move...."
The strange man closed the cupboard and hid in the embrasure of a large window, drawing the curtains together. Did Mlle. Destange not see him? Did she not hear him? Calmly she turned on the electric lights; she and her father sat down close to each other. She opened a book she had brought with her, and commenced to read. After the lapse of a few minutes she said:
"Your secretary has gone."
"Yes, I don't see him."
"Do you like him as well as you did at first?" she asked, as if she were not aware of the illness of the real secretary and his replacement by Stickmann.
"Oh! yes."
Monsieur Destange's head bobbed from one side to the other. He was asleep. The girl resumed her reading. A moment later one of the window curtains was pushed back, and the strange man emerged and glided along the wall toward the door, which obliged him to pass behind Mon. Destange but in front of Clotilde, and brought him into the light so that Herlock Sholmes obtained a good view of the man's face. It was Arsène Lupin.
The Englishman was delighted. His forecast was verified; he had penetrated to the very heart of the mystery, and found Arsène Lupin to be the moving spirit in it.
Clotilde had not yet displayed any knowledge of his presence, although it was quite improbable that any movement of the intruder had escaped her notice. Lupin had almost reached the door and, in fact, his hand was already seeking the door-knob, when his coat brushed against a small table and knocked something to the floor. Monsieur Destange awoke with a start. Arsène Lupin was already standing in front of him, hat in hand, smiling.
"Maxime Bermond," exclaimed Mon. Destange, joyfully. "My dear Maxime, what lucky chance brings you here?"
"The wish to see you and Mademoiselle Destange."
"When did you return from your journey?"
"Yesterday."
"You must stay to dinner."
"No, thank you, I am sorry, but I have an appointment to dine with some friends at a restaurant."
"Come, to-morrow, then, Clotilde, you must urge him to come to-morrow. Ah! my dear Maxime.... I thought of you many times during your absence."
"Really?"
"Yes, I went through all my old papers in that cupboard, and found our last statement of account."
"What account?"
"Relating to the avenue Henri-Martin."
"Ah! do you keep such papers? What for?"
Then the three of them left the room, and continued their conversation in a small parlor which adjoined the library.
"Is it Lupin?" Sholmes asked himself, in a sudden access of doubt. Certainly, from all appearances, it was he; and yet it was also someone else who resembled Arsène Lupin in certain respects, and who still maintained his own individuality, features, and color of hair. Sholmes could hear Lupin's voice in the adjoining room. He was relating some stories at which Mon. Destange laughed heartily, and which even brought a smile to the lips of the melancholy Clotilde. And each of those smiles appeared to be the reward which Arsène Lupin was seeking, and which he was delighted to have secured. His success caused him to redouble his efforts and, insensibly, at the sound of that clear and happy voice, Clotilde's face brightened and lost that cold and listless expression which usually pervaded it.
"They love each other," thought Sholmes, "but what the deuce