"Watch the strokes," said the scientist, "and watch the legs after the twentieth."
"Fourteen, fifteen, sixteen," Hatch counted. Each time the wire touched, and each time came the spasmodic motion. "Seventeen, eighteen, nineteen, twenty."
The Thinking Machine, instead of touching the twenty-first time, held the wire aloft. At the instant it would have touched the flesh, according to the beat, there came the same quick, spasmodic twitch, and then the legs were still.
"You see the effect is precisely as if I had touched them the twenty-first time," explained The Thinking Machine, "and that, Mr. Hatch, is one of the things science doesn't attempt to explain. It can be explained some day-it will be explained, but--" He paused. "Darrow hasn't been captured yet?" he said.
"No; no trace of him yet," was the reply. "The police have sent out a general alarm for him all over the country, and to-day Burdock increased the reward he offered from five thousand to ten thousand dollars."
"One of my objections to dealing with the police is that they are prone to jump at conclusions," remarked The Thinking Machine. "I didn't say, of course, that Darrow was a murderer. He may have killed Miss Burdock,-he probably did,-but it isn't conclusive at all. Still he is the next link in the chain, so his presence is necessary."
Hatch gazed at him in amazement, and a hundred questions rushed to his lips. They were stilled by the sudden appearance in the doorway of a young man. A soft hat was pulled down over his eyes, and he was crouching as if about to spring. One hand, the right, was in his coat pocket, clutching something fiercely. His face was perfectly pallid, and roving, glittering eyes blazed with madness.
"Come in," suggested The Thinking Machine calmly.
"I-I must talk to you, quick!" the young man burst out. "It's a matter of the most vital importance, and--"
"I'm at your service, Mr. Darrow," remarked The Thinking Machine pleasantly. "Have a seat."
Darrow! Hatch was startled, made speechless, by the uncanny appearance of this man whom the police of the entire continent were seeking. Darrow was still crouching there in the doorway, staring at them.
"I risked everything to come here," declared the young man-and there was a menace in his tone. "I was on the stoop about to ring the bell when I glanced back and saw Detective Mallory turn the corner. I didn't wait to ring-the door was unfastened and I came on in. Mallory is probably coming here. I must talk to you-and I won't be taken alive. Do you understand what I say?"
"Perfectly," replied The Thinking Machine. "Mr. Mallory won't see you. Come in out of the door."
"No tricks!" warned Darrow fiercely.
"No tricks. Sit down."
With furtive glances to right and left along the hall, the young man entered and dropped into a seat in a corner, facing them. There was a long, tense silence, and finally the door bell rang. Darrow half rose and made as if to take his right hand from his pocket.
"That's Mallory," remarked The Thinking Machine, and he started toward the door.
Darrow took one step forward, blocking his way. "Understand, please," he began in a low, even voice. "I am utterly desperate, and I won't be taken! If you attempt to betray me, I--" He stopped.
The Thinking Machine walked round him to the door leading into the hall. Martha, his aged servant, was just passing.
"Mr. Mallory is at the door, Martha," said the scientist. "Tell him I am not in; but that I shall be at police headquarters within an hour, and Mr. Darrow will come with me."
He stepped back into the laboratory and closed the door, without even a glance at his visitor. They heard Martha open the front door, then they heard Mallory's heavy voice, finally Martha's answer, then the door was closed, and Martha's footsteps passed along the hall. Darrow suddenly rushed to the window and glanced out.
"All right, Mr. Darrow," remarked the little scientist, as he sat down. "I know now you are innocent; I know why you have been hiding out, I know why you came here to see me, and I understand too your deep grief; so we can come immediately to the vital things."
The young man turned and glared at the small, impassive figure. "You said I would be at police headquarters with you in an hour," he said accusingly.
"Certainly," agreed the scientist impatiently. "As an innocent man you will go there of your own free will, with me."
The young man dropped into a chair and sat there for a long time with his face in his hands. After awhile Hatch saw a teardrop trickle through the unsteady fingers, and the shoulders moved convulsively. The Thinking Machine sat with head tilted back, squinting upward and fingers at rest, tip to tip.
"This trouble between you and Mr. Burdock?" suggested the scientist at last.
"You don't know the malignant hatred he has for me," said Darrow suddenly. "He is not a man of great wealth, but he is a man of great power, great influence, and if I should fall into the hands of the police with the circumstantial case against me that now exists he would bring all that power and influence to bear against me, with the result that I should be railroaded to a felon's grave. I don't know just how he would do it; but he would do it. I'm afraid of him-that's why I came here to see you when I wouldn't dare go to the police. I won't be taken by the police until I know I can prove my innocence; then I will surrender."
The Thinking Machine nodded.
"The enmity existing between us is of years' standing, and is not of importance here," Darrow went on. "But I know this man's power,-I have felt it all my life,-he has brought me to the edge of starvation half a dozen times, pursued me in every walk of life, until now-now if I should have to commit murder, he would be the victim. I'm telling you this because--"
"All this is of no consequence," interrupted The Thinking Machine shortly. "Who poisoned the rose?"
"I don't know," replied Darrow helplessly.
"You must have some idea," insisted The Thinking Machine.
"I did have an idea," was the reply. "I went this morning to a place to see a-a person whom I intended to accuse openly of the crime, taking the chance of capture myself, much as I dreaded it; but there was no one there. The door was locked; a servant connected with the apartment house told me that the-the person had not been there for a day or so."
The Thinking Machine turned quickly in his chair and glared at Darrow curiously.
"What's her name?" he demanded sharply.
"I don't know that she could have had anything to do with it," warned Darrow. "It seems awful to suggest such a thing, and yet--" He stopped. "I will go there with you to see her if you wish."
"Mr. Hatch," directed The Thinking Machine, "step into the next room there and telephone for a cab." He turned again to Darrow. "She threatened you, or Miss Burdock, I imagine?"
"Yes," said Darrow reluctantly.
"And now, please, one last question," said the little scientist. "What relation existed between you and Miss Burdock?"
"She was my wife," Darrow replied in a low voice. "We were secretly married four months ago."
"Um-m," mused the scientist. "I imagined as much."
Detective Mallory impatiently strode back and forth across his private office, his brain turbulent with conjecture. The telephone bell rang; The Thinking Machine was at the other end of the wire.
"Come at once and bring the medical examiner to the Craddock apartments!" commanded the irritable voice of the little scientist.
"Another murder?" demanded the detective, aghast.
"No, a suicide," was the reply. "Good by."
Detective Mallory and Medical Examiner Francis found The Thinking Machine, Hutchinson Hatch, and Paul K. Darrow in the sitting room of a small apartment on the fourth floor. Some sinister thing lay outstretched on a couch, covered with a sheet.
"Mr. Mallory, this is Mr. Darrow," the scientist remarked. "And here," he indicated the couch, "is the woman who murdered Miss Burdock, or rather Mrs. Darrow. Her name is Maria di Peculini. Here is a full confession in her own handwriting," he passed an envelope to the detective, "and here are several torn pieces of paper which show how assiduously she practised before show forged Mr. Darrow's handwriting in addressing the box in which the red rose was sent to Miss-I should say Mrs. Darrow. I may add that Signorina di Peculini killed herself by inhaling hydrocyanic acid-perhaps you know it better as Prussic acid-in a bottle from which came the single drop, allowed to settle in the bloom of the rose, which killed Mrs.Darrow."
Detective Mallory remained standing still for a long time to take it all in. At last he opened the confession-only a dozen lines-and read it from end to end. It was a pitiful, disjointed, almost incoherent, revelation of a woman's distorted soul. She too had loved Darrow, and this had changed to hate when he drifted away from her. Then, when by her own hand she had removed the woman he had made his wife, and had sought subtly to place the blame on him by the little forgery,-then had come a revulsion of feeling. She loved again, and overcome by remorse sought relief in death.
"There was no mystery whatever as to the cause of death," The Thinking Machine told Detective Mallory and Hatch a little while later. "Murder by poison was obvious from the fact that both the woman and the dog were dead; and when we knew that there was no mark or scratch on the dog, and the autopsy revealed nothing, we knew by the simplest rule of logic that the poison had been inhaled. The most powerful poison to inhale is hydrocyanic acid,-it kills instantly,-therefore it occurred to me first. It is so powerful that it is never made pure, at least in this country. The strongest you can buy in a drug store, for instance, is about a two per cent solution. One drop of a stronger solution than that, on a rose bloom, would have killed Miss Burdock, and the dog if he sniffed at it, as he must have.