Three days later came another tragedy. Bartow Gillespie and his brother James were found dead in a room together ten miles from the scene of the Barrett affair. Bartow, the eldest, had been strangled to death precisely as Mildred Barrett had been. James Gillespie lay five feet away, with a bullet in his brain. The murderer's revolver had fallen between them. One shot had been fired-the shot which entered James's head at the base of his brain.
The Thinking Machine and Hatch were on the scene of this second crime within a few hours. Again there was a detailed examination to be made, and the scientist made it conscientiously, from the strangler's cord, identical in every way with the one that had slain Mildred Barrett, to the revolver with its one empty chamber. The Thinking Machine weighed the weapon in his hand thoughtfully, and then turned to Detective Mallory.
"Whose is this?" he asked.
"If I knew that we could not only solve this mystery, but also the Barrett affair," retorted the detective grimly.
Then The Thinking Machine did a singular thing. He bent down to within a few inches of the upturned face of James Gillespie, and squinted steadily for a minute or more into the dead, glassy eyes. This done, he ran his slender white fingers through the dead man's hair several times.
"I know whose revolver it is now," he said as he arose. "It belonged to the other dead man there-Bartow Gillespie."
Detective Mallory regarded him in amazement for an instant, and then a slight smile about his lips showed what he thought of it.
"I suppose, professor," he said, "you are going to tell us that Bartow Gillespie killed his brother, and then strangled himself with this cord?"
"No," replied the scientist almost pleasantly.
"Well, then," Mallory ventured, "it's going to be that Bartow Gillespie shot his brother, and then his brother strangled him to death with the cord?"
"No," said the scientist again. "I was going to tell you that James Gillespie attacked his brother Bartow, and attempted to strangle him-did strangle him; that there was a struggle-these two overturned chairs show that; and that Bartow Gillespie, with the strangler's cord about his throat, killed his brother with the revolver. Remember, please, that when James Gillespie murdered Mildred Barrett, he was dealing with a child, but here he was dealing with a man, and a powerful man, who fought fiercely after the knot was fastened.
"We may assume that the revolver was Bartow Gillespie's, and that it was in his possession at the time he was attacked. Why? Because if it had been in James Gillespie's possession he would probably have finished his work by shooting his brother, when his brother began his struggle. Certainly James Gillespie did not kill himself, because the wound is in the back of his head. I am stating these things not as facts but as probabilities. When we know positively that the weapon was Bartow Gillespie's, then the probabilities become facts."
There was still a light, skeptical expression about Detective Mallory's mouth. "And on the other hand," he said, "we have the probability that the strangler came here and killed Bartow Gillespie, that the sound of the struggle attracted James Gillespie's attention, that he came in to investigate, that he was threatened and started to go out, and that the strangler fired the shot which struck him in the back of the head."
"Disproved flatly by two points," said The Thinking Machine curtly. "First, the fact that the strangler deliberately left his revolver, if we accept your hypothesis and second, by the fact that--" He paused and turning stared curiously down into the face of James Gillespie.
Detective Mallory waited impatiently for a moment; then, "And the second is what?" he asked.
"Do you know the motive for the murder of the Barrett child?" asked the scientist irrelevantly.
"No," said Detective Mallory in some surprise.
"And do you know the motive for this double crime, under your hypothesis?"
"No."
"Well, the motive is written here," and the scientist turned and thrust a long finger into the pallid face of James Gillespie. "It is in the eyes, in the mouth, and still again it's written here." He pulled aside the tumbled hair, and disclosed a bare spot. "Here is a scar, left months, perhaps years, ago by some serious injury."
"Why, I don't see--" began the detective protestingly.
"Of course, you don't see!" snapped The Thinking Machine. "What was found in James Gillespie's pockets?"
"I don't know that there has been an examination," said Mallory. "We always leave those things to the medical examiner, where there is no doubt of a man's identity."
With deft fingers the scientist ransacked the slain man's clothes. From a hip pocket he drew a little bundle and threw it on the table before Mallory. "And there is your final proof," he said. "It isn't even necessary now to prove that the revolver was Bartow Gillespie's-we know it-know it as inevitably as that two and two make four, Mr. Mallory, not sometimes but all the time."
The little bundle that he had thrown on the table was a roll of plain manila twine-just a couple of yards. At last the detective was beginning to see.
"But what possible motive?" he asked.
"I told Mr. Hatch when I investigated the Barrett affair that when all conceivable human motives were eliminated, as seemed to be the fact in this case, there remained only the thing-the creature, which will act without motive-an ape, for instance," interrupted The Thinking Machine. "I told him afterward that there would probably be a second crime under the same circumstances, and also that we were powerless to prevent it. This is the crime. There is no motive for either.
"The old scar on this man's head, the expression of his face, and his eyes particularly, show conclusively that he was a maniac-just a shade the intellectual superior of an ape, with all the cunning of humanity distorted and diseased into a homicidal mania. An examination of his brain at the autopsy will prove all this even to you, Mr. Mallory. How long he has been a maniac I don't know; your investigations will develop that. That is all, I think. Good day."
The Thinking Machine and Hutchinson Hatch walked down the street together.
"How is it," inquired the reporter, "that James Gillespie didn't kill Barrett at the same time he killed the little girl?"
"I don't know," was the reply. "It is difficult enough, Mr. Hatch, to follow the mental workings of a sane man; when we have a maniac, no one can say what he will do next. We don't look into the matter, but I dare say that Gillespie never knew that child he killed, and could have had no motive."
And subsequently this proved to be true.
PROBLEM OF THE LOST RADIUM.
One ounce of radium! Within his open palm Professor Dexter held practically the world's entire supply of that singular and seemingly inexhaustible force which was, and is, one of the greatest of all scientific riddles. So far as known there were only a few more grains in existence-four in the Curie laboratory in Paris, two in Berlin, two in St. Petersburg, one at Leland Stanford University and one in London. All the remainder was here-here in the Yarvard laboratory, a tiny mass lumped on a small piece of steel.
Gazing at this vast concentrated power Professor Dexter was a little awed and a little appalled at the responsibility which had suddenly devolved upon him, naturally enough with this culmination of a project which he had cherished for months. Briefly this had been to gather into one cohesive whole the many particles of the precious substance scattered over the world for the purpose of elaborate experiments as to its motive power practicability. Now here it was.
Its value, based on scarcity of supply, was incalculable. Millions of dollars would not replace it. Minute portions had come from the four quarters of the globe, in each case by special messenger, and each separate grain had been heavily insured by Lloyd's at a staggering premium. It was only after months of labour, backed by the influence of the great university of Yarvard in which he held the chair of physics, that Professor Dexter had been able to accomplish his purpose.
At least one famous name had been loaned to the proposed experiments, that of the distinguished scientist and logician, Professor Augustus S. F. X. Van Dusen-so called The Thinking Machine. The interest of this master mind in the work was a triumph for Professor Dexter, who was young and comparatively unknown. The elder scientist-The Thinking Machine-was a court of last appeal in the sciences and from the moment his connection with Professor Dexter's plans was announced his fellows all over the world had been anxiously awaiting a first word.
Naturally the task of gathering so great a quantity of radium had not been accomplished without extensive, and sometimes sensational, newspaper comment all over the United States and Europe. It was not astonishing, therefore that news of the receipt of the final portion of the radium at Yarvard had been known in the daily press and with it a statement that Professors Van Dusen and Dexter would immediately begin their experiments.
The work was to be done in the immense laboratory at Yarvard a high-ceilinged room with roof partially of glass, and with windows set high in the walls far above the reach of curious eyes. Full preparations had been made;-the two men were to work together, and a guard was to be stationed at the single door. This door led into a smaller room, a sort of reception hall, which in turn connected with the main hallway of the building.
Now Professor Dexter was alone in the laboratory, waiting impatiently for The Thinking Machine and turning over in his mind the preliminary steps in the labour he had undertaken. Every instrument was in place, all else was put aside for these experiments, which were either to revolutionize the motive power of the world or else demonstrate the utter uselessness of radium as a practical force.
Professor Dexter's line of thought was interrupted by the appearance of Mr. Bowen, one of the instructors of the University.
"A lady to see you, Professor," he said as he handed him a card. "She said it was a matter of great importance to you."
Professor Dexter glanced at the card as Mr. Bowen turned and went out through the small room into the main hallway. The name, Mme. Therese du Chastaigny, was wholly unfamiliar. Puzzled a little and perhaps impatient too, he carefully laid the steel with its burden of radium on the long table, and started out into the reception room. Almost in the door he stumbled against something, recovered his equilibrium with an effort and brought up with an undignified jerk.
The colour mounted to his modest ears as he heard a woman laugh-a pleasant, musical, throaty sort of ripple that under other circumstances would have been agreeable. Now, being directed at his own discomfiture, it was irritating, and the Professor's face tingled a little as a tall woman arose and came towards him.
"Please pardon me," she said contritely, but there was still a flicker of a smile upon her red lips. "It was my carelessness. I should not have placed my suit case in the door." She lifted it easily and replaced it in that identical position. "Or perhaps," she suggested, inquiringly, "someone else coming out might stumble as you did?"
"No," replied the Professor, and he smiled a little through his blushes. "There is no one else in there."
As Mme. du Chastaigny straightened up, with a rustle of skirts, to greet him Professor Dexter was somewhat surprised at her height and at the splendid lines of her figure. She was apparently of thirty years and seemed from a casual glance, to be five feet nine or ten inches tall. In addition to a certain striking indefinable beauty she was of remarkable physical power if one might judge from her poise and manner. Professor Dexter glanced at her and then at the card inquiringly.
"I have a letter of introduction to you from Mme. Curie of France," she explained as she produced it from a tiny chatelaine bag. "Shall we go over here where the light is better?"