CHAPTER II. THE MYSTERY DEEPENS.

Although the moment was obviously one that demanded caution, Jules Peret was never the man to hesitate in the face of an unknown danger.

He realized that he was in the presence of some terrible invisible thing that might strike him down at any moment, but, as he had no idea what that thing was and could not hope to cope with it until it attacked him or in some manner made itself manifest, he dismissed it from his mind for the moment and turned his attention to the two men who had gone down before its onslaught.

Kneeling beside Dr. Sprague’s prostrate form, he bent over and peered in the physician’s face. One look at the horribly distorted features and the glassy eyes that stared into his own told him that the man was dead.

Turning now from the dead to the living, Peret jumped to his feet and ran to help the pedestrian who, with the help of the terrified little druggist, was in the act of staggering to his feet. Although the druggist’s teeth were chattering with fear, his first thought seemed to be for the sufferer, and he helped Peret support the man, too weak to stand unaided, when he reeled back against the fence.

Choking, gasping, spitting, the pedestrian fought manfully to regain his breath. His face was purple with congested blood, and his glazed eyes were bulging. Great beads of sweat poured from his forehead and mingling with the froth that oozed from between his lips, flecked his face as he [119] twisted his head from side to side in agony.

“What is the matter with you?” shouted Peret. “Speak! I want to help you.”

The stricken man made a violent effort to throw off the invisible horror that had him in its clutches. Then the muscles of his body relaxed, and he ceased to struggle. Drawing in a deep breath of air, he expelled it with a sharp whistling sound. Then, exhausted, he shook off Peret’s hand, and sank down on the pavement in a sitting posture.

“ Sacrebleu! ” yelled Peret. “Speak to me, my friend, so I can avenge you! One little word is all I ask. What attacked you? ”

“I—I don’t know,” the man gasped. “It—It was something I could not see! It was a monster—an invisible monster. It whispered in my ear, and then it began to choke me. Oh, God—.”

His head fell forward; he began to sob weakly.

“An invisible monster,” repeated Peret, staring at the man curiously. “What do you mean by that?”

Before the man could reply, the police patrol-wagon swung around the corner and, with a clang of the bell, drew up to the curb. Detective Sergeant Strange of the homicide squad and two subordinates leaped to the sidewalk and approached the Frenchman.

“Well?” demanded Strange, with characteristic brevity.

“Murder,” returned Peret, with equal conciseness, and nodded at the two bodies on the pavement.

“How?” Strange shot out.

“I don’t know,” replied Peret. “As I was passing the house ten minutes ago, Max Berjet, the man on your left, hurled himself through the window, cried out that he had been attacked by ten assassins, and died immediately afterward. After summoning a physician, I started to enter the house to investigate, and heard the doctor scream. When I turned I saw Dr. Sprague and this man”—pointing to the pedestrian—“struggling in the grasp of something I could not see. Before I could reach them, the two men fell to the pavement. Dr. Sprague died almost instantly; this other man, as you see, is recovering. He has just informed me that he was attacked by an invisible monster.”

Strange’s bellicose features twisted into a grin.

“An invisible monster, eh? Well, it had better stay invisible if it’s still sticking around.” He whirled about, and to the patrolman: “I want all available men here on the jump, Bill. Call the coroner at the same time. O’Shane”—to one of the plainclothes men who accompanied him—“watch the front of that house and keep an eye on these bodies until the coroner comes. Mike, take care of the back of the house, and,” he added with a grim humor, “keep your eye peeled for an ‘invisible monster’.”

Strange turned once more to the Frenchman.

“You’re sure these two men are dead, Peret?”

“They will never be any deader,” replied Peret shortly.

“All right—Who is that man?”—pointing over his shoulder at the druggist.

“I am the proprietor of the drug store across the street,” spoke up the druggist. “I ran over with Dr. Sprague, who happened to be in the store when this gentleman summoned assistance.”

Strange nodded.

“I may have to hold you as a witness,” was his curt reply. “Stick around until I can find time to question you. Now Peret, before we enter the house, spill the details. What do you know about this ‘invisible monster’?”

“Little more than I have already told you,” answered Peret, and [120] launched into a detailed recital of his harrowing experience.

Although Detective Strange was a man difficult to surprise, he made no effort to conceal his astonishment when Peret brought his story to an end.

“You say Dr. Sprague and this other man were seized by the Thing when your back was turned?” he questioned.

“ Oui ; as I was leaping over the fence,” nodded Peret, “I heard Dr. Sprague scream just as I landed on the ground. When I turned to see what was the matter, both he and the other man appeared to be struggling with some invisible antagonist. Before I could reach them, both men fell to the ground. Sprague was apparently dead before he fell. The other man, after a struggle, threw off the Thing—whatever it was or is.”

“Didn’t you see anything at all?” demanded Strange.

“Absolutely nothing.”

“Hear anything?”

“No. But that man”—jerking his thumb at the pedestrian—“said he heard the Thing whisper.”

“I also heard the Thing whisper,” interposed the druggist, a small, bald-headed individual with a cataract over one of his eyes. Still in a state of nervous apprehension, he had edged up close to the two detectives as if seeking their protection. “I was talking to Dr. Sprague when he was attacked,” he continued, darting furtive glances over his shoulder from time to time. “An instant before he screamed I heard a—a whispering sound.”

Peret’s eyes shone with interest.

“It’s strange that I did not hear this sound,” he muttered, half to himself. “Just what, exactly, do you mean by a whispering sound, Monsieur? ”

“I scarcely know,” replied the druggist, after a moment’s thought. “It was a whisper—nothing that I could understand. Just an inarticulate whisper . I had hardly heard it when Sprague screamed and began to struggle.”

“Whence did the whisper emanate, Monsieur ?” queried Peret eagerly.

“I do not know.”

“You saw nothing?”

“Nothing.”

“’S damn funny,” growled Strange, scratching his ear. “An ‘invisible monster’ that whispers is a new one on me.” He looked at the Frenchman, perplexedly. “Queer business, Peret.”

“It is,” agreed Peret; then whirled around to confront the pedestrian. “Ah, Monsieur , perhaps you can help us a little, eh? How are you feeling now?”

“Considerably better,” returned the other in a hoarse voice, and then added, “But I don’t believe I’ll ever recover from the shock. What in God’s name was it, anyway?”

He was a tall, heavy-set man with glittering black eyes, a close-cropped mustache and, though his features were irregular, had rather a handsome countenance. Although deathly pale and still a little shaken, he seemed to have himself pretty well in hand.

Strange looked at him shrewdly.

“What’s your name?” he asked, taking out his notebook.

“Albert Deweese,” replied the man. “I am an artist and have a studio in the next block. I was on my way home when I heard the crash of breaking glass as Mr. Berjet jumped through the window-sash. Naturally, I ran back to find out what the trouble was.”

Strange made a note and nodded.

“What attacked you?” he suddenly shot out.

“I don’t know,” replied Deweese. “The Thing, whatever it was, was invisible. I felt it, God knows, but did not see it.”

“But you must have some idea of what the Thing was,” Strange insisted. “Was it a man, or an animal, or—?”

Deweese shook his head slowly.

“I have said that I do not know,” was his emphatic reply, “and I do not. How could I, when I did not see it? It was large, powerful and ferocious, but whether it was an animal of some kind, or a demon out of hell, I do not know.”

“Perhaps your ears served you better than your eyes?” said Strange. “Did you hear the Thing when it leaped upon you?”

“I did,” replied Deweese, with a shudder. “At almost the very instant that it attacked me I heard it whisper.”

“ Eh, bien, Monsieur ,” cried Peret, “and what did it say to you?”

“It did not say anything intelligible,” was Deweese’s disappointing reply. “It just whispered.”

Strange and Peret looked at each other in silence. The Frenchman shrugged his shoulders, and exhaled a cloud of cigarette smoke. Strange took a hitch in his trousers, and his face became stern.

“All right,” he said curtly to Deweese. “Stick around till the coroner comes. I want to question you and this other man further, a little later on.”

He gave an order to O’Shane, who was standing a little distance away with his eyes glued on the front of Berjet’s house, then turned to Peret.

“I’m going in,” he growled, and drew his revolver.

The Frenchman threw his cigarette on the pavement, drew his own automatic, and, opening the front gate, ran across the little yard. Followed by Strange and Deweese, who asked and obtained permission to accompany them, Peret buttoned his coat around his frail body, got a firm grip on the window ledge and, with the agility of a monkey, climbed through the broken sash of the window through which Berjet had projected himself.

The room in which the detectives found themselves had evidently been the scientist’s sitting room. It was simply but comfortably furnished and was quite masculine in character. The walls were lined with well-filled book shelves, and in the center of the room was a large table, littered with a miscellany of papers, pamphlets, pipes, burnt matches and tobacco ashes. On the carpeted floor near the table lay an open book, the leaves of which were rumpled and torn. Except for this, the room was in perfect order.

“No signs of gas anywhere,” said Strange, audibly sniffing the air. “The asphyxiation theory of Dr. Sprague’s is a dud, in my opinion.”

Peret, who had begun to make an inspection of the room, did not reply. Strange continued his investigation, while Deweese stood near the window looking on.

The result of Peret’s examination, which, while brief, was more or less thorough, annoyed and confounded him. The detective sergeant also appeared to be puzzled. The Frenchman was the first to give expression to his thoughts.

“The three doors and the four windows in this room, sergeant, are locked on the inside ,” he remarked, as Strange paused for a moment to look at him with questioning eyes. “The key to that door on the far side of the room, and which I am sure is the door of a closet, is missing, but the other keys are in the locks. The windows, moreover, are, as you have no doubt observed, fastened with a form of mechanism that could not possibly have been sprung from the outside. Yet Berjet said he was attacked by ten assassins!”

“The point that you are trying to make, I take it,” Strange grunted, “is that the broken window is the only means of egress from the room.”

“Your penetration is remarkable,” snapped Peret, who always became irritated when baffled.

“It’s the devil’s own work,” commented Deweese, who had been watching [122] the movements of the two detectives with keen interest. “Certainly there was nothing human about the Thing that attacked me, and I imagine that Berjet’s death can be laid at the door of the same agency.”

Peret flung himself into a chair and lit a cigarette.

“Any way you look at the thing, it seems preposterous,” he said reflectively. “The ‘invisible monster’ theory is too absurd for serious consideration, and the other theories that have been advanced do not stand up in the presence of the facts. However, let us consider. We will assume that Berjet was, as he said, attacked by ten men. Eh! bien! How did they get out of the room? All of the exits are locked on the inside, as you see.

“There is a small transom over that door opening onto the hall, it is true, but it is not large enough for a child to crawl through, much less a man. Dr. Sprague seemed to think that Berjet was asphyxiated. Yet this room, as you yourself observed when we entered it, sergeant, contained not the slightest trace of any kind of gas. As a matter of fact, the room is lighted by electricity. What are we to conclude from these premises? That the poison fumes, assuming that poison fumes were the cause of Berjet’s death, were administered by human hands? If so, oblige me, my friend, by telling me how the owner of those hands got out of the room?”

“Well, if the murderers were invisible, and they were, if the testimony of you and Deweese counts for anything,” rejoined Strange, “they might have followed Berjet through the window without having been observed by you.”

“ Invisible murderers!” snorted Peret, with a contemptuous shrug of his shoulders. “You are growing feeble-minded, my friend. Didn’t Berjet say he saw his murderers?”

“So you say,” returned Strange rudely. “But you didn’t see Sprague’s murderer, although you claim to have been looking at him when he was attacked. Maybe your eyesight is failing you,” he added.

Peret glared at the detective sergeant, but said nothing.

“Perhaps Berjet was subject to a hallucination,” ventured Strange, after a moment’s thought. “He may just have imagined he saw the murderers.”

“Perhaps he just imagined he was murdered, too,” retorted the Frenchman, and returned to his examination of the room.

At this juncture someone rapped on the door opening into the hall. Strange crossed the room, turned the key in the lock and, opening the door, admitted Central Bureau Detectives Frank and O’Shane.

“Well?” demanded Strange.

“Major Dobson sent us four men from headquarters, and we’ve searched the house as you ordered,” answered O’Shane. “We drew an absolute blank. The house is empty.”

“Hasn’t Berjet got a family?” inquired Strange.

“The people next door say that Berjet’s wife and daughter are spending the winter at Palm Beach.”

“Ain’t they any servants?”

“All of the servants go home at night except Adolphe, the murdered man’s valet.”

“Did you find him?”

“No.”

“Was the front door, and the rest of the doors and windows in the house, locked?”

“The front door was not only unlocked but slightly ajar. The rest of the house was secured.”

“Do you not think it possible that the murderer might have slipped out of the front door while you were watching without being seen by you?”

“Absolutely not,” said O’Shane, emphatically. “I didn’t take my eye off the front of the house after you entered it until the men the major sent arrived. Mike watched the back of the house with equal care. Nobody [123] could a-got out without one of us knowin’ it. If a murder’s been committed the murderer’s still in the house somewhere.”

The burly sergeant nodded his satisfaction.

“Well, if he’s here, we’ll get him,” he declared. As an after-thought: “Got the house surrounded?”

“I’ve thrown a cordon around the whole block,” replied O’Shane. “A mouse couldn’t get through it without getting its neck broke.”

“Good.” Strange drew his revolver, which he had returned to his pocket after entering the room, and tried the handle of the closet door. “Now, men, before we go any farther, let’s get this closet open. It may contain a secret exit, for all we know. Take a chair and burst it in, one of you.”

“Wait, my friend, I know an easier way,” said Peret.

He drew a jimmy from his inside coat pocket, inserted the flattened end in the crack between the door and the jamb, and bore down on the handle. Yielding to the powerful leverage, the door creaked, splintered around the lock and flew open.

“Ten thousand devils!” cried Peret, leaping back.

The body of a dead man rolled out on the floor!