A violent ringing of the bell awakened the concierge of number nine, avenue Hoche. She pulled the doorstring, grumbling:  
“I thought everybody was in. It must be three o’clock!”
 
“Perhaps it is some one for the doctor,” muttered her husband.
 
“Third floor, left. But the doctor won’t go out at night.”
 
“He must go to-night.”
 
The visitor entered the vestibule, ascended to the first floor, the second, the third, and, without stopping at the doctor’s door, he continued to the fifth floor. There, he tried two keys. One of them fitted the lock.
 
“Ah! good!” he murmured, “that simplifies the business wonderfully. But before I commence work I had better arrange for my retreat. Let me see.... have I had sufficient time to rouse the doctor and be dismissed by him? Not yet.... a few minutes more.”
 
At the end of ten minutes, he descended the stairs, grumbling noisily about the doctor. The concierge opened the door for him and heard it click behind him. But the door did not lock, as the man had quickly inserted a piece of iron in the lock in such a manner that the bolt could not enter. Then, quietly, he entered the house again, unknown to the concierge. In case of alarm, his retreat was assured. Noiselessly, he ascended to the fifth floor once more. In the antechamber, by the light of his electric lantern, he placed his hat and overcoat on one of the chairs, took a seat on another, and covered his heavy shoes with felt slippers.
 
“Ouf! Here I am—and how simple it was! I wonder why more people do not adopt the profitable and pleasant occupation of burglar. With a little care and reflection, it becomes a most delightful profession. Not too quiet and monotonous, of course, as it would then become wearisome.”
 
He unfolded a detailed plan of the apartment.
 
“Let me commence by locating myself. Here, I see the vestibule in which I am sitting. On the street front, the drawing-room, the boudoir and dining-room. Useless to waste any time there, as it appears that the countess has a deplorable taste.... not a bibelot of any value!...Now, let’s get down to business!... Ah! here is a corridor; it must lead to the bed chambers. At a distance of three metres, I should come to the door of the wardrobe-closet which connects with the chamber of the countess.” He folded his plan, extinguished his lantern, and proceeded down the corridor, counting his distance, thus:
 
“One metre.... two metres.... three metres....Here is the door....Mon Dieu, how easy it is! Only a small, simple bolt now separates me from the chamber, and I know that the bolt is located exactly one metre, forty-three centimeters, from the floor. So that, thanks to a small incision I am about to make, I can soon get rid of the bolt.”
 
He drew from his pocket the necessary instruments. Then the following idea occurred to him:
 
“Suppose, by chance, the door is not bolted. I will try it first.”
 
He turned the knob, and the door opened.
 
“My brave Lupin, surely fortune favors you....What’s to be done now? You know the situation of the rooms; you know the place in which the countess hides the black pearl. Therefore, in order to secure the black pearl, you have simply to be more silent than silence, more invisible than darkness itself.”
 
Arsène Lupin was employed fully a half-hour in opening the second door—a glass door that led to the countess’ bedchamber. But he accomplished it with so much skill and precaution, that even had had the countess been awake, she would not have heard the slightest sound. According to the plan of the rooms, that he holds, he has merely to pass around a reclining chair and, beyond that, a small table close to the bed. On the table, there was a box of letter-paper, and the black pearl was concealed in that box. He stooped and crept cautiously over the carpet, following the outlines of the reclining-chair. When he reached the extremity of it, he stopped in order to repress the throbbing of his heart. Although he was not moved by any sense of fear, he found it impossible to overcome the nervous anxiety that one usually feels in the midst of profound silence. That circumstance astonished him, because he had passed through many more solemn moments without the slightest trace of emotion. No danger threatened him. Then why did his heart throb like an alarm-bell? Was it that sleeping woman who affected him? Was it the proximity of another pulsating heart?
 
He listened, and thought he could discern the rhythmical breathing of a person asleep. It gave him confidence, like the presence of a friend. He sought and found the armchair; then, by slow, cautious movements, advanced toward the table, feeling ahead of him with outstretched arm. His right had touched one of the feet of the table. Ah! now, he had simply to rise, take the pearl, and escape. That was fortunate, as his heart was leaping in his breast like a wild beast, and made so much noise that he feared it would waken the countess. By a powerful effort of the will, he subdued the wild throbbing of his heart, and was about to rise from the floor when his left hand encountered, lying on the floor, an object which he recognized as a candlestick—an overturned candlestick. A moment later, his hand encountered another object: a clock—one of those small traveling clocks, covered with leather. ———-
 
Well! What had happened? He could not understand. That candlestick, that clock; why were those articles not in their accustomed places? Ah! what had happened in the dread silence of the night?
 
Suddenly a cry escaped him. He had touched—oh! some strange, unutterable thing! “No! no!” he thought, “it cannot be. It is some fantasy of my excited brain.” For twenty seconds, thirty seconds, he remained motionless, terrified, his forehead bathed with perspiration, and his fingers still retained the sensation of that dreadful contact.
 
Making a desperate effort, he ventured to extend his arm again. Once more, his hand encountered that strange, unutterable thing. He felt it. He must feel it and find out what it is. He found that it was hair, human hair, and a human face; and that face was cold, almost icy.
 
However frightful the circumstances may be, a man like Arsène Lupin controls himself and commands the situation as soon as he learns what it is. So, Arsène Lupin quickly brought his lantern into use. A woman was lying before him, covered with blood. Her neck and shoulders were covered with gaping wounds. He leaned over her and made a closer examination. She was dead.
 
“Dead! Dead!” he repeated, with a bewildered air.
 
He stared at those fixed eyes, that grim mouth, that livid flesh, and that blood—all that blood which had flowed over the carpet and congealed there in thick, black spots. He arose and turned on the electric lights. Then he beheld all the marks of a desperate struggle. The bed was in a state of great disorder. On the floor, the candlestick, and the clock, with the hands pointing to twenty minutes after eleven; then, further away, an overturned chair; and, everywhere, there was blood, spots of blood and pools of blood.
 
“And the black pearl?” he murmured.
 
The box of letter-paper was in its place. He opened it, eagerly. The jewel-case was there, but it was empty.
 
“Fichtre!” he muttered. “You boasted of your good fortune much too soon, my friend Lupin. With the countess lying cold and dead, and the black pearl vanished, the situation is anything but pleasant. Get out of here as soon as you can, or you may get into serious trouble.”
 
Yet, he did not move.
 
“Get out of here? Yes, of course. Any person would, except Arsène Lupin. He has something better to do. Now, to proceed in an orderly way. At all events, you have a clear conscience. Let us suppose that you are the commissary of police and that you are proceeding to make an inquiry concerning this affair——Yes, but in order to do that, I require a clearer brain. Mine is muddled like a ragout.”
 
He tumbled into an armchair, with his clenched hands pressed against his burning forehead.
 
The murder of the avenue Hoche is one of those which have recently surprised and puzzled the Parisian public, and, certainly, I should never have mentioned the affair if the veil of mystery had not been removed by Arsène Lupin himself. No one knew the exact truth of the case.
 
Who did not know—from having met her in the Bois—the fair Léotine Zalti, the once-famous cantatrice, wife and widow of the Count d’Andillot; the Zalti, whose luxury dazzled all Paris some twenty years ago; the Zalti who acquired an European reputation for the magnificence of her diamonds and pearls? It was said that she wore upon her shoulders the capital of several banking houses and the gold mines of numerous Australian companies. Skilful jewelers worked for Zalti as they had formerly wrought for kings and queens. And who does not remember the catastrophe in which all that wealth was swallowed up? Of all that marvelous collection, nothing remained except the famous black pearl. The black pearl! That is to say a fortune, if she had wished to part with it.
 
But she preferred to keep it, to live in a commonplace apartment with her companion, her cook, and a man-servant, rather than sell that inestimable jewel. There was a reason for it; a reason she was not afraid to disclose: the black pearl was the gift of an emperor! Almost ruined, and reduced to the most mediocre existence, she remained faithful to the companion of her happy and brilliant youth. The black pearl never left her possession. She wore it during the day, and, at night, concealed it in a place known to her alone.
 
All these facts, being republished in the columns of the public press, served to stimulate curiosity; and, strange to say, but quite obvious to those who have the key to the mystery, the arrest of the presumed assassin only complicated the question and prolonged the excitement. Two days later, the newspapers published the following item:
 
“Information has reached us of the arrest of Victor Danègre, the servant of the Countess d’Andillot. The evidence against him is clear and convincing. On the silken sleeve of his liveried waistcoat, which chief detective Dudouis found in his garret between the mattresses of his bed, several spots of blood were discovered. In addition, a cloth-covered button was missing from that garment, and this button was found beneath the bed of the victim.
 
“It is supposed that, after dinner, in place of going to his own room, Danègre slipped into the wardrobe-closet, and, through the glass door, had seen the countess hide the precious black pearl. This is simply a theory, as yet unverified by any evidence. There is, also, another obscure point. At seven o’clock in the morning, Danègre went to the tobacco-shop on the Boulevard de Courcelles; the concierge and the shop-keeper both affirm this fact. On the other hand, the countess’ companion and cook, who sleep at the end of the hall, both declare that, when they arose at eight o’clock, the door of the antechamber and the door of the kitchen were locked. These two persons have been in the service of the countess for twenty years, and are above suspicion. The question is: How did Danègre leave the apartment? Did he have another key? These are matters that the police will investigate.”
 
As a matter of fact, the police investigation threw no light on the mystery. It was learned that Victor Danègre was a dangerous criminal, a drunkard and a debauchee. But, as they proceeded with the investigation, the mystery deepened and new complications arose. In the first place, a young woman, Mlle. De Sinclèves, the cousin and sole heiress of the countess, declared that the countess, a month before her death, had written a letter to her and in it described the manner in which the black pearl was concealed. The letter disappeared the day after she received it. Who had stolen it?
 
Again, the concierge related how she had opened the door for a person who had inquired for Doctor Harel. On being questioned, the doctor testified that no one had rung his bell. Then who was that person? And accomplice?
 
The theory of an accomplice was thereupon adopted by the press and public, and also by Ganimard, the famous detective.
 
“Lupin is at the bottom of this affair,” he said to the judge.
 
“Bah!” exclaimed the judge, “you have Lupin on the brain. You see him everywhere.”
 
“I see him everywhere, because he is everywhere.”
 
“Say rather that you see him every time you encounter something you cannot explain. Besides, you overlook the fact that the crime was committed at twenty minutes past eleven in the evening, as is shown by the clock, while the nocturnal visit, mentioned by the concierge, occurred at three o’clock in the morning.”
 
Officers of the law frequently form a hasty conviction as to the guilt of a suspected person, and then distort all subsequent discoveries to conform to their established theory. The deplorable antecedents of Victor Danègre, habitual criminal, drunkard and rake, influenced the judge, and despite the fact that nothing new was discovered in corroboration of the early clues, his official opinion remained firm and unshaken. He closed his investigation, and, a few weeks later, the trial commenced. It proved to be slow and tedious. The judge was listless, and the public prosecutor presented the case in a careless manner. Under those circumstances, Danègre’s counsel had an easy task. He pointed out the defects and inconsistencies of the case for the prosecution, and argued that the evidence was quite insufficient to convict the accused. Who had made the key, the indispensable key without which Danègre, on leaving the apartment, could not have locked the door behind him? Who had ever seen such a key, and what had become of it? Who had seen the assassin’s knife, and where is it now?
 
“In any event,” argued the prisoner’s counsel, “the prosecution must prove, beyond any reasonable doubt, that the prisoner committed the murder. The prosecution must show that the mysterious individual who entered the house at three o’clock in the morning is not the guilty party. To be sure, the clock indicated eleven o’clock. But what of that? I contend, that proves nothing. The assassin could turn the hands of the clock to any............