With expert fingers Phillip Dunston, receiving teller, verified the last package of one hundred dollar bills he had made up — ten thousand dollars in all — and tossed it over on the pile beside him, while he checked off a memorandum. It was correct; there were eighteen packages of bills, containing $107,231. Then he took the bundles, one by one, and on each placed his initials, “P. D.” This was a system of checking in the Ralston National Bank.

It was care in such trivial details, perhaps, that had a great deal to do with the fact that the Ralston National had advanced from a small beginning to the first rank of those banks which were financial powers. President Quinton Fraser had inaugurated the system under which the Ralston National had so prospered, and now, despite his seventy-four years, he was still its active head. For fifty years he had been in its employ; for thirtyfive years of that time he had been its president.

Publicly the aged banker was credited with the possession of a vast fortune, this public estimate being based on large sums he had given to charity. But as a matter of fact the private fortune of the old man, who had no one to share it save his wife, was not large; it was merely a comfortable living sum for an aged couple of simple tastes.

Dunston gathered up the packages of money and took them into the cashier’s private office, where he dumped them on the great flat-top desk at which that official, Randolph West, sat figuring. The cashier thrust the sheet of paper on which he had been working into his pocket and took the memorandum which Dunston offered.

“All right?” he asked.

“It tallies perfectly,” Dunston replied.

“Thanks. You may go now.”

It was an hour after closing time. Dunston was just pulling on his coat when he saw West come out of his private office with the money to put it away in the big steel safe which stood between depositors and thieves. The cashier paused a moment to allow the janitor, Harris, to sweep the space in front of the safe. It was the late afternoon scrubbing and sweeping.

“Hurry up,” the cashier complained, impatiently.

Harris hurried, and West placed the money in the safe. There were eighteen packages.

“All right, sir?” Dunston inquired.

“Yes.”

West was disposing of the last bundle when Miss Clarke — Louise Clarke — private secretary to President Fraser, came out of his office with a long envelope in her hand. Dunston glanced at her and she smiled at him.

“Please, Mr. West,” she said to the cashier, “Mr. Fraser told me before he went to put these papers in the safe. I had almost forgotten.”

She glanced into the open safe and her pretty blue eyes opened wide. Mr. West took the envelope, stowed it away with the money without a word, the girl looking on interestedly, and then swung the heavy door closed. She turned away with a quick, reassuring smile at Dunston, and disappeared inside the private office.

West had shot the bolts of the safe into place and had taken hold of the combination dial to throw it on, when the street door opened and President Fraser entered hurriedly.

“Just a moment, West,” he called. “Did Miss Clarke give you an envelope to go in there?”

“Yes. I just put it in.”

“One moment,” and the aged president came through a gate which Dunston held open and went to the safe. The cashier pulled the steel door open, unlocked the money compartment where the envelope had been placed, and the president took it out.

West turned and spoke to Dunston, leaving the president looking over the contents of the envelope. When the cashier turned back to the safe the president was just taking his hand away from his inside coat pocket.

“It’s all right, West,” he instructed. “Lock it up.”

Again the heavy door closed, the bolts were shot and the combination dial turned. President Fraser stood looking on curiously; it just happened that he had never witnessed this operation before.

“How much have you got in there tonight?” he asked.

“One hundred and twenty-nine thousand,” replied the cashier. “And all the securities, of course.”

“Hum,” mused the president. “That would be a good haul for some one — if they could get it, eh, West?” and he chuckled dryly.

“Excellent,” returned West, smilingly. “But they can’t.”

Miss Clarke, dressed for the street, her handsome face almost concealed by a veil which was intended to protect her pink cheeks from boisterous winds, was standing in the door of the president’s office.

“Oh, Miss Clarke, before you go, would you write just a short note for me?” asked the president.

“Certainly,” she responded, and she returned to the private office. Mr. Fraser followed her.

West and Dunston stood outside the bank railing, Dunston waiting for Miss Clarke. Every evening he walked over to the subway with her. His opinion of her was an open secret. West was waiting for the janitor to finish sweeping.

“Hurry up, Harris,” he said again.

“Yes, sir,” came the reply, and the janitor applied the broom more vigorously. “Just a little bit more. I’ve finished inside.”

Dunston glanced through the railing. The floor was spick and span and the hardwood glistened cleanly. Various bits of paper came down the corridor before Harris’s broom. The janitor swept it all up into a dustpan just as Miss Clarke came out of the president’s room. With Dunston she walked up the street. As they were going they saw Cashier West come out the front door, with his handkerchief in his hand, and then walk away rapidly.

“Mr. Fraser is doing some figuring,” Miss Clarke explained to Dunston. “He said he might be there for another hour.”

“You are beautiful,” replied Dunston, irrelevantly.

These, then, were the happenings in detail in the Ralston National Bank from 4:15 o’clock on the afternoon of November 11. That night the bank was robbed. The great steel safe which was considered impregnable was blown and $129,000 was missing.

The night watchman of the bank, William Haney, was found senseless, bound and gagged, inside the bank. His revolver lay beside him with all the cartridges out. He had been beaten into insensibility; at the hospital it was stated that there was only a bare chance of his recovery.

The locks, hinges and bolts of the steel safe had been smashed by some powerful explosive, possibly nitro-glycerine. The tiny dial of the time-lock showed that the explosion came at 2:39; the remainder of the lock was blown to pieces.

Thus was fixed definitely the moment at which the robbery occurred. It was shown that the policeman on the beat had been four blocks away. It was perfectly possible that no one heard the explosion, because the bank was situated in a part of the city wholly given over to business and deserted at night.

The burglars had entered the building through a window of the cashier’s private office, in the full glare of an electric light. The window sash here had been found unfastened and the protecting steel bars, outside from top to bottom, seemed to have been dragged from their sockets in the solid granite. The granite crumbled away, as if it had been chalk.

Only one possible clew was found. This was a white linen handkerchief, picked up in front of the blown safe. It must have been dropped there at the time of the burglary, because Dunston distinctly recalled it was not there before he left the bank. He would have noticed it while the janitor was sweeping.

This handkerchief was the property of Cashier West. The cashier did not deny it, but could offer no explanation of how it came there. Miss Clarke and Dunston both said that they had seen him leave the bank with a handkerchief in his hand.
2

President Fraser reached the bank at ten o’clock and was informed of the robbery. He retired to his office, and there he sat, apparently stunned into inactivity by the blow, his head bowed on his arms. Miss Clarke, at her typewriter, frequently glanced at the aged figure with an expression of pity on her face. Her eyes seemed weary, too. Outside, through the closed door, they could hear the detectives.

From time to time employees of the bank and detectives entered the office to ask questions. The banker answered as if dazed; then the board of directors met and voted to personally make good the loss sustained. There was no uneasiness among depositors, because they knew the resources of the bank were practically unlimited.

Cashier West was not arrested. The directors wouldn’t listen to such a thing; he had been cashier for eighteen years, and they trusted him implicitly. Yet he could offer no possible explanation of how his handkerchief had come there. He asserted stoutly that he had not been in the bank from the moment Miss Clarke and Dunston saw him leave it.

After investigation the police placed the burglary to the credit of certain expert cracksmen, identity unknown. A general alarm, which meant a rounding up of all suspicious persons, was sent out, and this drag-net was expected to bring important facts to light. Detective Mallory said so, and the bank officials placed great reliance on his word.

Thus the situation at the luncheon hour. Then Miss Clarke, who, wholly unnoticed, had been waiting all morning at her typewriter, arose and went over to Fraser.

“If you don’t need me now,” she said, “I’ll run out to luncheon.”

“Certainly, certainly,” he responded, with a slight start. He had apparently forgotten her existence.

She stood silently looking at him for a moment.

“I’m awfully sorry,” she said, at last, and her lips trembled slightly.

“Thanks,” said the banker, and he smiled faintly. “It’s a shock, the worst I ever had.”

Miss Clarke passed out with quiet tread, pausing for a moment in the outer office to stare curiously at the shattered steel safe. The banker arose with sudden determination and called to West, who entered immediately.

“I know a man who can throw some light on this thing,” said Fraser, positively. “I think I’ll ask him to come over and take a look. It might aid the police, anyway. You may know him? Professor Van Dusen.”

“Never heard of him,” said West, tersely, “but I’ll welcome anybody who can solve it. My position is uncomfortable.”

President Fraser called Professor Van Dusen — The Thinking Machine — and talked for a moment through the ‘phone. Then he turned back to West.

“He’ll come,” he said, with an air of relief. “I was able to do him a favor once by putting an invention on the market.”

Within an hour The Thinking Machine, accompanied by Hutchinson Hatch, reporter, appeared. President Fraser knew the scientist well, but on West the strange figure made a startling, almost uncanny, impression. Every known fact was placed before The Thinking Machine. He listened without comment, then arose and wandered aimlessly about the offices. The employees were amused by his manner; Hatch was a silent looker-on.

“Where was the handkerchief found?” demanded The Thinking Machine, at last.

“Here,” replied West, and he indicated the exact spot.

“Any draught through the office — ever?”

“None. We have a patent ventilating system which prevents that.”

The Thinking Machine squinted for several minutes at the window which had been unfastened — the window in the cashier’s private room — with the steel bars guarding it, now torn out of their sockets, and at the chalklike softness of the granite about the sockets. After awhile he turned to the president and cashier.

“Where is the handkerchief?”

“In my desk,” Fraser replied. “The police thought it of no consequence, save, perhaps — perhaps — ” and he looked at West.

“Except that it might implicate me,” said West, hotly.

“Tut, tut, tut,” said Fraser, reprovingly. “No one thinks for a —”

“Well, well, the handkerchief?” interrupted The Thinking Machine, in annoyance.

“Come into my office,” suggested the president.

The Thinking Machine started in, saw a woman — Miss Clarke, who had returned from luncheon — and stopped. There was one thing on earth he was afraid of — a woman.

“Bring it out here,” he requested.

President Fraser brought it and placed it in the slender hands of the scientist, who examined it closely by a window, turning it over and over. At last he sniffed at it. There was the faint, clinging odor of violet perfume. Then abruptly, irrelevantly, he turned to Fraser.

“How many women employed in the bank?” he asked.

“Three,” was the reply; “Miss Clarke, who is my secretary, and two general stenographers in the outer office.”

“How many men?”

“Fourteen, including myself.”

If the president and Cashier West had been surprised at the actions of The Thinking Machine up to this point, now they were amazed. He thrust the handkerchief at Hatch, took his own handkerchief, briskly scrubbed his hands with it, and also passed that to Hatch.

“Keep those,” he commanded.

He sniffed at his hands, then walked into the outer office, straight toward the desk of one of the young women stenographers. He leaned over her, and asked one question:

“What system of shorthand do you write?”

“Pitman,” was the astonished reply.

The scientist sniffed. Yes, it was unmistakably a sniff. He left her suddenly and went to the other stenographer. Precisely the same thing happened; standing close to her he asked one question, and at her answer sniffed. Miss Clarke passed through the outer office to mail a letter. She, too, had to answer the question as the scientist squinted into her eyes, and sniffed.

“Ah,” he said, at her answer.

Then from one to another of the employees of the bank he went, asking each a few questions. By this time a murmur of amusement was running through the office. Finally The Thinking Machine approached the cage in which sat Dunston, the receiving teller. The young man was bent over his work, absorbed.

“How long have e you been employed here?” asked the scientist, suddenly.

Dunston started and glanced around quickly.

“Five years,” he responded.

“It must be hot work,” said The Thinking Machine. “You’re perspiring.”

“Am I?” inquired the young man, smilingly.

He drew a crumpled handkerchief from his hip pocket, shook it out, and wiped his forehead.

“Ah!” exclaimed The Thinking Machine, suddenly.

He had caught the faint, subtle perfume of violets — an odor identical with that on the handkerchief found in front of the safe.
3

The Thinking Machine led the way back to the private office of the cashier, with President Fraser, Cashier West and Hatch following.

“Is it possible for anyone to overhear us here?” he asked.

“No,” replied the president. “The directors meet here.”

“Could anyone outside hear that, for instance?” and with a sudden sweep of his hand he upset a heavy chair.

“I don’t know,” was the astonished reply. “Why?”

The Thinking Machine went quickly to the door, opened it softly and peered out. Then he closed the door again.

“I suppose I may speak with absolute frankness?” he inquired.

“Certainly,” responded the old banker, almost startled. “Certainly.”

“You have presented an abstract problem,” The Thinking Machine went on, “and I presume you want a solution of it, no matter where it hits?”

“Certainly,” the president again assured him, but his tone expressed a grave, haunting fear.

“In that case,” and The Thinking Machine turned to the reporter, “Mr. Hatch, I want you to ascertain several things for me. First, I want to know if Miss Clarke uses or has ever used violet perfume — if so, when she ceased using it.”

“Yes,” said the reporter. The bank officials exchanged wondering looks.

“Also, Mr. Hatch,” and the scientist squinted with his strange eyes straight into the face of the cashier, “go to the home of Mr. West, here, see for yourself his laundry mark, and ascertain beyond any question if he has ever, or any member of his family has ever, used violet perfume.”

The cashier flushed suddenly.

“I can answer that,” he said, hotly. “No.”

“I knew you would say that,” said The Thinking Machine, curtly. “Please don’t interrupt. Do as I say, Mr. Hatch.”

Accustomed as he was to the peculiar methods of this man, Hatch saw faintly the purpose of the inquiries.

“And the receiving teller?” he asked.

“I know about him,” was the reply.

Hatch left the room, closing the door behind him. He heard the bolt shot in the lock as he started away.

“I think it only fair to say here, Professor Van Dusen,” explained the president, “that we understand thoroughly that it would have been impossible for Mr. West to have had anything to do with or know —”

“Nothing is impossible,” interrupted The Thinking Machine.

“But I won’t —” began West, angrily.

“Just a moment, please,” said The Thinking Machine. “No one has accused you of anything. What I am doing may explain to your satisfaction just how your handkerchief came here and bring about the very thing I suppose you want — exoneration.”

The cashier sank back into a chair; President Fraser looked from one to the other. Where there had been worry on his face there was now only wonderment.

“Your handkerchief was found in this office, apparently having been dropped by the persons who blew the safe,” and the long, slender fingers of The Thinking Machine were placed tip to tip as he talked. “It was not there the night before. The janitor who swept says so; Dunston, who happened to look, says so; Miss Clarke and Dunston both say they saw you with a handkerchief as you left the bank. Therefore, that handkerchief reached that spot after you left and before the robbery was discovered.”

The cashier nodded.

“You say you don’t use perfume; that no one in your family uses it. If Mr. Hatch verifies this, it will help to exonerate you. But some person who handled that handkerchief after it left your possession and before it appeared here did use perfume. Now who was that person? Who would have had an opportunity?

“We may safely dismiss the possibility that you lost the handkerchief, that it fell into the hands of burglars, that those burglars used perfume, that they brought it to your bank — your own bank, mind you! — and left it. The series of coincidences necessary to bring that about would not have occurred once in a million times.”

The Thinking Machine sat silent for several minutes, squinting steadily at the ceiling.

“If it had been lost anywhere, in the laundry, say, the same rule of coincidence I have just applied would almost eliminate it. Therefore, because of an opportunity to get that handkerchief, we will assume — there is — there must be-some one employed in this bank who had some connection with or actually participated in the burglary.”

The Thinking Machine spoke with perfect quiet, but the effect was electrical. The aged president staggered to his feet and stood staring at him dully; again the flush of crimson came into the face of the cashier.

“Some one,” The Thinking Machine went on, evenly, “who either found the handkerchief and unwittingly lost it at the time of the burglary, or else stole it and deliberately left it. As I said, Mr. West seems eliminated. Had he been one of the robbers, he would not wittingly have left his handkerchief; we will still assume that he does not use perfume, therefore personally did not drop the handkerchief where it was found.”

“Impossible! I can’t believe it, and of my employees —” began Mr. Fraser.

“Please don’t keep saying things are impossible,” snapped The Thinking Machine. “It irritates me exceedingly. It all comes to the one vital question: Who in the bank uses perfume?”

“I don’t know,” said the two officials.

“I do,” said The Thinking Machine. “There are two — only two, Dunston, your receiving teller, and Miss Clarke.”

“But they —”

“Dunston uses a violet perfume not like that on the handkerchief, but identical with it,” The Thinking Machine went on. “Miss Clarke uses a strong rose perfume.”

“But those two persons, above all others in the bank, I trust implicitly,” said Mr. Fraser, earnestly. “And, besides, they wouldn’t know how to blow a safe. The police tell me this was the work of experts.”

“Have you, Mr. Fraser, attempted to raise, or have you raised lately, any large sum of money?” asked the scientist, suddenly.

“Well, yes,” said the banker, “I have. For a week past I have tried to raise ninety thousand dollars on my personal account.”

“And you, Mr. West?”

The face of the cashier flushed slightly — it might have been at the tone of the question — and there was the least pause.

“No,” he answered finally.

“Very well,” and the scientist arose, rubbing his hands; “now we’ll search your employees.”

“What?” exclaimed both men. Then Mr. Fraser added: “That would be the height of absurdity; it would never do. Besides, any person who robbed the bank would not carry proofs of the robbery, or even any of the money about with them — to the bank, above all places.”

“The bank would be the safest place for it,” retorted The Thinking Machine. “It is perfectly possible that a thief in your employ would carry some of the money; indeed, it is doubtful if he would dare do anything else with it. He could see you would have no possible reason for suspecting anyone here — unless it is Mr. West.”

There was a pause. “I’ll do the searching, except the three ladies, of course,” he added, blushingly. “With them each combination of two can search the other one.”

Mr. Fraser and Mr. West conversed in low tones for several minutes.

“If the employees will consent I am willing,” Mr. Fraser explained, at last; “although I see no use of it.”

“They will agree,” said The Thinking Machine. “Please call them all into this office.”

Among some confusion and wonderment the three women and fourteen men of the bank were gathered in the cashier’s office, the outer doors being locked. The Thinking Machine addressed them with characteristic terseness.

“In the investigation of the burglary of last night,” he explained, “it has been deemed necessary to search all employees of this bank.” A murmur of surprise ran around the room. “Those who are innocent will agree readily, of course; will all agree?”

There were whispered consultations on all sides. Dunston flushed angrily; Miss Clarke, standing near Mr. Fraser, paled slightly. Dunston looked at her and then spoke.

“And the ladies?” he asked.

“They, too,” explained the scientist. “They may searched one another — in the other room, of course.”

“I for one will not submit to such a proceeding,” Dunston declared, bluntly, “not because I fear it, but because it is an insult.”

Simultaneously it impressed itself on the bank officials and The Thinking Machine that the one person in the bank who used a perfume identical with that on the handkerchief was the first to object to a search. The cashier and president exchanged startled glances.

“Nor will I,” came in the voice of a woman.

The Thinking Machine turned and glanced at her. It was Miss Willis, one of the outside stenographers; Miss Clarke and the other woman were pale, but neither had spoken.

“And the others?” asked The Thinking Machine.

Generally there was acquiescence, and as the men came forward the scientist searched them, perfunctorily, it seemed. Nothing! At last there remained three men, Dunston, West and Fraser. Dunston came forward, compelled to do so by the attitude of his fellows. The three women stood together. The Thinking Machine spoke to them as he searched Dunston.

“If the ladies will retire to the next room they may proceed with their search,” he suggested. “If any money is found, bring it to me — nothing else.”

“I will not, I will not, I will not,” screamed Miss Willis, suddenly. “It’s an outrage.”

Miss Clarke, deathly white and half fainting, threw up her hands and sank without a sound into the arms of President Fraser. There she burst into tears.

“It is an outrage,” she sobbed. She clung to President Fraser, her arms flung upward and her face buried on his bosom. He was soothing her with fatherly words, and stroked her hair awkwardly. The Thinking Machine finished the search of Dunston. Nothing! Then Miss Clarke roused herself and dried her eyes.

“Of course I will have to agree,” she said, with a flash of anger in her eyes.

Miss Willis was weeping, but, like Dunston, she was compelled to yield, and the three women went into an adjoining room. There was a tense silence until they reappeared. Each shook her head. The Thinking Machine nearly looked disappointed.

“Dear me!” he exclaimed. “Now, Mr. Fraser.” He started toward the president, then paused to pick up a scarf pin.

“This is yours,” he said. “I saw it fall,” and he made as if to search the aged man.

“Well, do you really think it necessary in my case?” asked the president, in consternation, as he drew back, nervously. “I— I am the president, you know.”

“The others were searched in your presence, I will search you in their presence,” said The Thinking Machine, tartly.

“But — but —” the president stammered.

“Are you afraid?” the scientist demanded.

“Why, of course not,” was the hurried answer; “but it seems so — so unusual.”

“I think it best,” said The Thinking Machine, and before the banker could draw away his slender fingers were in the inside breast pocket, whence they instantly drew out a bundle of money — one hundred $100 bills — ten thousand dollars — with the initials of the receiving teller, “P. D.”—“o. k. — R. W.”

“Great God!” exclaimed Mr. Fraser, ashen white.

“Dear me, dear me!” said The Thinking Machine again. He sniffed curiously at the bundle of bank notes, as a hound might sniff at a trail.
4

President Fraser was removed to his home in a dangerous condition. His advanced age did not withstand the shock. Now alternately he raved and muttered incoherently, and the old eyes were wide, staring fearfully always. There was a consultation between The Thinking Machine and West after the removal of President Fraser, and the result was another hurried meeting of the board of directors. At that meeting West was placed, temporarily, in command. The police, of course, had been informed of the matter, but no arrest was probable.

Immediately after The Thinking Machine left the bank Hatch appeared and inquired for him. From the bank he went to the home of the scientist. There Professor Van Dusen was bending over a retort, busy with some problem.

“Well?” he demanded, as he glanced up.

“West told the truth,” began Hatch. “Neither he nor any member of his family uses perfume; he has few outside acquaintances, is regular in his habits, but is a man of considerable wealth, it appears.”

“What is his salary at the bank?” asked The Thinking Machine.

“Fifteen thousand a year,” said the reporter. “But he must have a large fortune. He lives like a millionaire.”

“He couldn’t do that on fifteen thousand dollars a year,” mused the scientist. “Did he inherit any money?”

“No,” was the reply. “He started as a clerk in the bank and has made himself what he is.”

“That means speculation,” said The Thinking Machine. “You can’t save a fortune from a salary, even fifteen thousand dollars a year. Now, Mr. Hatch, find out for me all about his business connections. His source of income particularly I would like to know. Also whether or not he has recently sought to borrow or has received a large sum of money; if he got it and what he did with it. He says he has not sought such a sum. Perhaps he told the truth.”

“Yes, and about Miss Clarke —”

“Yes; what about her?” asked The Thinking Machine.

“She occupies a little room in a boardinghouse for women in an excellent district,” the reporter explained. “She has no friends who call there, at any rate. Occasionally, however, she goes out at night and remains late.”

“The perfume?” asked the scientist.

“She uses a perfume, the housekeeper tells me, but she doesn’t recall just what kind it is — so many of the young women in the house use it. So I went to her room and looked. There was no perfume there. Her room was considerably disarranged, which seemed to astonish the housekeeper, who declared that she had carefully arranged it about nine o’clock. It was two when I was there.”

“How was............