"Murder?" gasped Cabell, at last.
"Yes, he speaks English all right," remarked The Thinking Machine. "Now, Mr. Cabell, will you please tell me just who Miss Austin is, and where she is, and her mental condition? Believe me, it may save you a great deal of trouble. What I said in the note is not exaggerated."
The young man turned suddenly and began to pace back and forth across the room. After a few minutes he paused before The Thinking Machine, who stood impatiently waiting for an answer.
"I'll tell you, yes," said Cabell, firmly. "Miss Austin is a middle-aged woman whom my sister befriended several times-was, in fact, my sister's governess when she was a child. Of late years she has not been wholly right mentally, and has suffered a great deal of privation. I had about concluded arrangements to put her in a private sanitarium. I permitted her to remain in these rooms in my absence, South. I did not take Jean-he lived in the quarters of the other employees of the place, and gave the apartment entirely to Miss Austin. It was simply an act of charity."
"What was the cause of your sudden determination to go South to-night?" asked the scientist.
"I won't answer that question," was the sullen reply.
There was a long, tense silence. Jean, the valet, came and went several times.
"How long has Miss Austin known Mr. Henley?"
"Presumably since she has been in these apartments," was the reply.
"Are you sure you are not Miss Austin?" demanded the scientist.
The question was almost staggering, not only to Cabell, but to Hatch. Suddenly, with flaming face, the young Southerner leaped forward as if to strike down The Thinking Machine.
"That won't do any good," said the scientist, coldly. "Are you sure you are not Miss Austin?" he repeated.
"Certainly I am not Miss Austin," responded Cabell, fiercely.
"Have you a mirror in these apartments about twelve inches by twelve inches?" asked The Thinking Machine, irrelevantly.
"I-I don't know," stammered the young man. "I-have we, Jean?"
"Oui," replied the valet.
"Yes," snapped The Thinking Machine. "Talk English, please. May I see it?"
The valet, without a word but with a sullen glance at the questioner, turned and left the room. He returned after a moment with the mirror. The Thinking Machine carefully examined the frame, top and bottom and on both sides. At last he looked up; again the valet was bending over a suit case.
"Do you use gas in these apartments?" the scientist asked suddenly.
"No," was the bewildered response. "What is all this, anyway?"
Without answering, The Thinking Machine drew a chair up under the chandelier where the gas and electric fixtures were and began to finger the gas tips. After awhile he climbed down and passed into the next room, with Hatch and Cabell, both hopelessly mystified, following. There the scientist went through the same process of fingering the gas jets. Finally, one of the gas tips came out in his hand.
"Ah," he exclaimed, suddenly, and Hatch knew the note of triumph in it. The jet from which the tip came was just on a level with his shoulder, set between a dressing table and a window. He leaned over and squinted at the gas pipe closely. Then he returned to the room where the valet was.
"Now, Jean," he began, in an even, calm voice, "please tell me if you did or did not kill Miss Regnier purposely?"
"I don't know what you mean," said the servant sullenly, angrily, as he turned on the scientist.
"You speak very good English now," was The Thinking Machine's terse comment. "Mr. Hatch, lock the door and use this 'phone to call the police."
Hatch turned to do as he was bid and saw a flash of steel in young Cabell's hand, which was drawn suddenly from a hip pocket. It was a revolver. The weapon glittered in the light, and Hatch flung himself forward. There was a sharp report, and a bullet was buried in the floor.
VI.
Then came a fierce, hard fight for possession of the revolver. It ended with the weapon in Hatch's hand, and both he and Cabell blowing from the effort they had expended. Jean, the valet, had turned at the sound of the shot and started toward the door leading into the hall. The Thinking Machine had stepped in front of him, and now stood there with his back to the door. Physically he would have been a child in the hands of the valet, yet there was a look in his eyes which stopped him.
"Now, Mr. Hatch," said the scientist quietly, a touch of irony in his voice, "hand me the revolver, then 'phone for Detective Mallory to come here immediately. Tell him we have a murderer-and if he can't come at once get some other detective whom you know."
"Murderer!" gasped Cabell.
Uncontrollable rage was blazing in the eyes of the valet, and he made as if to throw The Thinking Machine aside, despite the revolver, when Hatch was at the telephone. As Jean started forward, however, Cabell stopped him with a quick, stern gesture. Suddenly the young Southerner turned on The Thinking Machine; but it was with a question.
"What does it all mean?" he asked, bewildered.
"It means that that man there," and The Thinking Machine indicated the valet by a nod of his head, "is a murderer-that he killed Louise Regnier; that he shot Welden Henley on Boston Common, and that, with the aid of Miss Regnier, he had four times previously attempted to kill Mr. Henley. Is he coming, Mr. Hatch?"
"Yes," was the reply. "He says he'll be here directly."
"Do you deny it?" demanded The Thinking Machine of the valet.
"I've done nothing," said the valet sullenly. "I'm going out of here."
Like an infuriated animal he rushed forward. Hatch and Cabell seized him and bore him to the floor. There, after a frantic struggle, he was bound and the other three men sat down to wait for Detective Mallory. Cabell sank back in his chair with a perplexed frown on his face. From time to time he glanced at Jean. The flush of anger which had been on the valet's face was gone now; instead there was the pallor of fear.
"Won't you tell us?" pleaded Cabell impatiently.
"When Detective Mallory comes and takes his prisoner," said The Thinking Machine.
Ten minutes later they heard a quick step in the hall outside and Hatch opened the door. Detective Mallory entered and looked from one to another inquiringly.
"That's your prisoner, Mr. Mallory," said the scientist, coldly. "I charge him with the murder of Miss Regnier, whom you were so confident committed suicide; I charge him with five attempts on the life of Weldon Henley, four times by gas poisoning, in which Miss Regnier was his accomplice, and once by shooting. He is the man who shot Mr. Henley."
The Thinking Machine arose and walked over to the prostate man, handing the revolver to Hatch. He glared down at Jean fiercely.
"Will you tell how you did it or shall I?" he demanded.
His answer was a sullen, defiant glare. He turned and picked up the square mirror which the valet had produced previously.
"That's where the screw was, isn't it?" he asked, as he indicated a small hole in the frame of the mirror. Jean stared at it and his head sank forward hopelessly. "And this is the bath robe you wore, isn't it?" he demanded again, and from the suit case he pulled out the garment with the scarlet stripe.
"I guess you got me all right," was the sullen reply.
"It might be better for you if you told the story then?" suggested The Thinking Machine.
"You know so much about it, tell it yourself."
"Very well," was the calm rejoinder. "I will. If I make any mistake you will correct me."