By Jacques Futrelle
"Really great criminals are never found out, for the simple reason that
the greatest crimes—their crimes—are never discovered," remarked
Professor Augustus S. F. X. Van Dusen positively. "There is genius in
the perpetration of crime, Mr. Grayson, just as there must be in its
detection, unless it is the shallow work of a bungler. In this latter
case there have been instances where even the police have uncovered the
truth. But the expert criminal, the man of genius—the professional, I
may say—regards as perfect only that crime which does not and cannot be
made to appear a crime at all; therefore one that can never under any
circumstances involve him, or anyone else."
The financier, J. Morgan Grayson, regarded this wizened little man of
science—The Thinking Machine—thoughtfully, through the smoke of his
"It is a strange psychological fact that the casual criminal glories in
his crime beforehand, and from one to ten minutes afterward," The
Thinking Machine continued. "For instance, the man who kills for revenge
wants the world to know it is his work; but at the end of ten minutes
comes fear, and then paradoxically enough, he will seek to hide his
crime and protect himself. With fear comes panic, with panic
irresponsibility, and then he makes the mistake—hews a pathway which
the trained mind follows from motive to a prison cell."
"These are the men who are found out. But there are men of genius, Mr.
Grayson, professionally engaged in crime. We never hear of them because
they are never caught, and we never even suspect them because they make
no mistake. Imagine the great brains of history turned to crime. Well,
there are today brains as great as any of those of history; there is
murder and theft and robbery under our noses that we never dream of. If
I, for instance, should become an active criminal——" He paused.
Grayson, with a queer expression on his face, puffed steadily at his
"I could kill you now, here in this room," The Thinking Machine went on
calmly, "and no one would ever know, never even suspect. Why? Because I
would make no mistake."
It was not a boast as he said it; it was merely a statement of fact.
Grayson appeared to be a little startled. Where there had been only
impatient interest in his manner, there was now fascination.
"How would you kill me, for instance?" he inquired curiously.
"With any one of a dozen poisons, with virulent germs, or even with a
knife or revolver," replied the scientist placidly. "You see, I know how
to use poisons; I know how to inoculate with germs; I know how to
produce a suicidal appearance perfectly with either a revolver or knife.
And I never make mistakes, Mr. Grayson. In the sciences we must be
exact—not approximately so, but absolutely so. We must know. It isn't
like carpentry. A carpenter may make a trivial mistake in a joint, and
it will not weaken his house; but if the scientist makes one mistake,
the whole structure tumbles down. We must know. Knowledge is progress.
We gain knowledge through observation and logic—inevitable logic. And
logic tells us that two and two make four—not sometimes but all the
Grayson flicked the ashes off his cigar thoughtfully, and little
wrinkles appeared about his eyes as he stared into the drawn,
inscrutable face of the scientist. The enormous, straw-yellow head was
cushioned against the chair, the squinting, watery blue eyes turned
upward, and the slender white fingers at rest, tip to tip. The financier
drew a long breath. "I have been informed that you were a remarkable
man," he said at last slowly. "I believe it. Quinton Frazer, the banker
who gave me the letter of introduction to you, told me how you once
solved a remarkable mystery in which——"
"Yes, yes," interrupted the scientist shortly, "the Ralston Bank
"So I came to you to enlist your aid in something which is more
inexplicable than that," Grayson went on hesitatingly. "I know that no
fee I might offer would influence you; yet it is a case which——"
"State it," interrupted The Thinking Machine again.
"It isn't a crime—that is, a crime that can be reached by law," Grayson
hurried on, "but it has cost me millions, and——"
For one instant The Thinking Machine lowered his squint eyes to those of
his visitor, then raised them again. "Millions!" he repeated. "How
"Six, eight, perhaps ten," was the reply. "Briefly, there is a leak in
my office. My plans become known to others almost by the time I have
perfected them. My plans are large; I have millions at stake; and the
greatest secrecy is absolutely essential. For years I have been able to
preserve this secrecy; but half a dozen times in the last eight weeks my
plans have become known, and I have been caught. Unless you know the
Street, you can't imagine what a tremendous disadvantage it is to have
someone know your next move to the minutest detail and, knowing it,
defeat you at every turn."
"No, I don't know your world of finance, Mr. Grayson," remarked The
Thinking Machine. "Give me an instance."
"Well, take this last case," said the financier earnestly. "Briefly,
without technicalities, I had planned to unload the securities of the
P., Q. & X. Railway, protecting myself through brokers, and force the
outstanding stock down to a price where other brokers, acting for me,
could buy far below the actual value. In this way I intended to get
complete control of the stock. But my plans became known, and when I
began to unload everything was snapped up by the opposition, with the
result that instead of gaining control of the road I lost heavily. This
same thing has happened, with variations, half a dozen times."
"I presume that is strictly honest?" inquired the scientist mildly.
"Honest?" repeated Grayson. "Certainly—of course."
"I shall not pretend to understand all that," said The Thinking Machine
curtly. "It doesn't seem to matter, anyway. You want to know where the
leak is. Is that right?"
"Well, who is in your confidence?"
"No one, except my stenographer."
"Who is he, please?"
"It's a woman—Miss Evelyn Winthrop. She has been in my employ for six
years in the same capacity—more than five years before this leak
appeared. I trust her absolutely."
"No man knows your business?"
"No," replied the financier grimly. "I learned years ago that no one
could keep my secrets as well as I do—there are too many temptations.
Therefore, I never mention my plans to anyone—never—to anyone!"
"Except your stenographer," corrected the scientist.
"I work for days, weeks, sometimes months, perfecting plans, and it's
all in my head, not on paper—not a scratch of it," explained Grayson.
"When I say that she is in my confidence, I mean that she knows my plans
only half an hour or less before the machinery is put into motion. For
instance, I planned this P., Q. & X. deal. My brokers didn't know of it;
Miss Winthrop never heard of it until twenty minutes before the Stock
Exchange opened for business. Then I dictated to her, as I always do,
some short letters of instructions to my agents. That is all she knew of
"You outlined the plan in those letters?"
"No; they merely told my brokers what to do."
"But a shrewd person, knowing the contents of all those letters, could
have learned what you intended to do?"
"Yes; but no one person knew the contents of all the letters. No one
broker knew what was in the other letters. Miss Winthrop and I were the
only two human beings who knew all that was in them."
The Thinking Machine sat silent for so long that Grayson began to fidget
in his chair. "Who was in the room besides you and Miss Winthrop before
the letters were sent?" he asked at last.
"No one," responded Grayson emphatically. "For an hour before I dictated
those letters, until at least an hour afterward, after my plans had gone
to smash, no one entered that room. Only she and I work there."
"But when she finished the letters, she went out?" insisted The Thinking
"No," declared the financier, "she didn't even leave her desk."
"Or perhaps sent something out—carbon copies of the letters?"
"Or called up a friend on the telephone?" continued The Thinking Machine
"Nor that," retorted Grayson.
"Or signaled to someone through the window?"
"No," said the financier again. "She finished the letters, then remained
quietly at her desk, reading a book. She hardly moved for two hours."
The Thinking Machine lowered his eyes and glared straight into those of
the financier. "Someone listened at the window?" he went on after a
"No. It is sixteen stories up, fronting the street, and there is no fire
"Or the door?"
"If you knew the arrangement of my offices, you would see how utterly
impossible that would be, because—"
"Nothing is impossible, Mr. Grayson," snapped the scientist abruptly.
"It might be improbable, but not impossible. Don't say that—it annoys
me exceedingly." He was silent for a moment. Grayson stared at him
blankly. "Did either you or she answer a call on the 'phone?"
"No one called; we called no one."
"Any apertures—holes or cracks—in your flooring or walls or ceilings?"
demanded the scientist.
"Private detectives whom I had employed looked for such an opening, and
there was none," replied Grayson.
Again The Thinking Machine was silent for a long time. Grayson lighted a
fresh cigar and settled back in his chair patiently. Faint cobwebby
lines began to appear on the dome-like brow of the scientist, and slowly
the squint eyes were narrowing.
"The letters you wrote were intercepted?" he suggested at last.
"No," exclaimed Grayson flatly. "Those letters were sent direct to the
brokers by a dozen different methods, and every one of them had been
delivered by five minutes of ten o'clock, when 'Change begins business.
The last one left me at ten minutes of ten."
"Dear me! Dear me!" The Thinking Machine rose and paced the length of
"You don't give me credit for the extraordinary precautions I have
taken, particularly in this last P., Q. & X. deal," Grayson continued.
"I left positively nothing undone to insure absolute secrecy. And Miss
Winthrop, I know, is innocent of any connection with the affair. The
private detectives suspected her at first, as you do, and she was
watched in and out of my office for weeks. When she was not under my
eyes, she was under the eyes of men to whom I had promised an
extravagant sum of money if they found the leak. She didn't know it
then, and doesn't know it now. I am heartily ashamed of it all, because
the investigation proved her absolute loyalty to me. On this last day
she was directly under my eyes for two hours; and she didn't make one
movement that I didn't note, because the thing meant millions to me.
That proved beyond all question that it was no fault of hers. What could
The Thinking Machine didn't say. He paused at a window, and for minute
after minute stood motionless there, with eyes narrowed to mere slits.
"I was on the point of discharging Miss Winthrop," the financier went
on, "but her innocence was so thoroughly proved to me by this last
affair that it would have been unjust, and so——"
Suddenly the scientist turned upon his visitor. "Do you talk in your
sleep?" he demanded.
"No," was the prompt reply. "I had thought of that too. It is beyond all
ordinary things, Professor. Yet there is a leak that is costing me
"It comes down to this, Mr. Grayson," The Thinking Machine informed him
crabbedly. "If only you and Miss Winthrop knew those plans, and no one
else, and they did leak, and were not deduced from other things, then
either you or she permitted them to leak, intentionally or
unintentionally. That is as pure logic as two and two make four; there
is no need to argue it."
"Well, of course, I didn't," said Grayson.
"Then Miss Winthrop did," declared The Thinking Machine finally,
positively; "unless we credit the opposition, as you call it, with
telepathic gifts hitherto unheard of. By the way, you have referred to
the other side only as the opposition. Do the same men, the same clique,
appear against you all the time, or is it only one man?"
"It's a clique," explained the financier, "with millions back of it,
headed by Ralph Matthews, a young man to whom I give credit for being
the prime factor against me." His lips were set sternly.
"Why?" demanded the scientist.
"Because every time he sees me he grins," was the reply. Grayson seemed
The Thinking Machine went to a desk, addressed an envelope, folded a
sheet of paper, placed it inside, then sealed it. At length he turned
back to his visitor. "Is Miss Winthrop at your office now?"
"Let us go there, then."
A few minutes later the eminent financier ushered the eminent scientist
into his private office on the Street. The only person there was a young
woman—a woman of twenty-six or-seven, perhaps—who turned, saw Grayson,
and resumed reading. The financier motioned to a seat. Instead of
sitting, however, The Thinking Machine went straight to Miss Winthrop
and extended a sealed envelop to her.
"Mr. Ralph Matthews asked me to hand you this," he said.
The young woman glanced up into his face frankly, yet with a certain
timidity, took the envelope, and turned it curiously in her hand.
"Mr. Ralph Matthews," she repeated, as if the name was a strange one. "I
don't think I know him."
The Thinking Machine stood staring at her aggressively, as she opened
the envelope and drew out the sheet of paper. There was no expression
save surprise—bewilderment, rather—to be read on her face.
"Why, it's a blank sheet!" she remarked, puzzled.
The scientist turned suddenly toward Grayson, who had witnessed the
incident with frank astonishment in his eyes. "Your telephone a moment,
please," he requested.
"Certainly; here," replied Grayson.
"This will do," remarked the scientist.
He leaned forward over the desk where Miss Winthrop sat, still gazing at
him in a sort of bewilderment, picked up the receiver, and held it to
his ear. A few moments later he was talking to Hutchinson Hatch,
"I merely wanted to ask you to meet me at my apartment in an hour," said
the scientist. "It is very important."
That was all. He hung up the receiver, paused for a moment to admire an
exquisitely wrought silver box—a "vanity" box—on Miss Winthrop's desk,
beside the telephone, then took a seat beside Grayson and began to
discourse almost pleasantly upon the prevailing meteorological
conditions. Grayson merely stared; Miss Winthrop continued her reading.
Professor Augustus S. F. X. Van Dusen, distinguished scientist, and
Hutchinson Hatch, newspaper reporter, were poking round among the
chimney pots and other obstructions on the roof of a skyscraper. Far
below them the slumber-enshrouded city was spread out like a panorama,
streets dotted brilliantly with lights, and roofs hazily visible through
mists of night. Above, the infinite blackness hung like a veil, with
starpoints breaking through here and there.
"Here are the wires," Hatch said at last, and he stooped.
The Thinking Machine knelt on the roof beside him, and for several
minutes they remained thus in the darkness, with only the glow of a
flashlight to indicate their presence. Finally, The Thinking Machine
"That's the wire you want, Mr. Hatch," he said. "I'll leave the rest of
it to you."
"Are you sure?" asked the reporter.
"I am always sure," was the tart response.
Hatch opened a small handsatchel and removed several queerly wrought
tools. These he spread on the roof beside him; then, kneeling again,
began his work. For half an hour he labored in the gloom, with only the
flashlight to aid him, and then he rose.
"It's all right," he said.
The Thinking Machine examined the work that had been done, grunted his
satisfaction, and together they went to the skylight, leaving a thin,
insulated wire behind them, stringing along to mark their path. They
passed down through the roof and into the darkness of the hall of the
upper story. Here the light was extinguished. From far below came the
faint echo of a man's footsteps as the watchman passed through the
silent, deserted building.
"Be careful!" warned The Thinking Machine.
They went along the hall to a room in the rear, and still the wire
trailed behind. At the last door they stopped. The Thinking Machine
fumbled with some keys, then opened the way. Here an electric light was
on. The room was bare of furniture, the only sign of recent occupancy
being a telephone instrument on the wall.
Here The Thinking Machine stopped and stared at the spool of wire which
he had permitted to wind off as he walked, and his thin face expressed
"It wouldn't be safe," he said at last, "to leave the wire exposed as we
have left it. True, this floor is not occupied; but someone might pass
this way and disturb it. You take the spool, go back to the roof,
winding the wire as you go, then swing the spool down to me over the
side of the building, so that I can bring it in through the window. That
will be best. I will catch it here, and thus there will be nothing to
indicate any connection." Hatch went out quietly and closed the door.
Twice the following day The Thinking Machine spoke to the financier over
the telephone. Grayson was in his private office, Miss Winthrop at her
desk, when the first call came.
"Be careful in answering my questions," warned The Thinking Machine when
Grayson answered. "Do you know how long Miss Winthrop has owned the
little silver box which is now on her desk, near the telephone?"
Grayson glanced round involuntarily to where the girl sat idly turning
over the leaves of her book. "Yes," he answered, "for seven months. I
gave it to her last Christmas."
"Ah!" exclaimed the scientist. "That simplifies matters. Where did you
Grayson mentioned the name of a well-known jeweler.
Considerably later in the day The Thinking Machine called Grayson to the
"What make of typewriter does she use?" came the querulous voice over
Grayson named it.
While Grayson sat with deeply perplexed lines in his face, the
diminutive scientist called upon Hutchinson Hatch at his office.
"Do you use a typewriter?" demanded The Thinking Machine.
"Oh, four or five kinds—we have half a dozen different makes in the
They passed along through the city room, at that moment practically
deserted, until finally the watery blue eyes settled upon a typewriter
with the name emblazoned on the front.
"That's it!" exclaimed The Thinking Machine. "Write something on it," he
Hatch drew up a chair and rolled off several lines of the immortal
practice sentence, beginning, "Now is the time for all good men—"
The Thinking Machine sat beside him, squinting across the room in deep
abstraction, and listening intently. His head was turned away from the
reporter, but his ear was within a few inches of the machine. For half a
minute he sat there listening, then shook his head.
"Strike your vowels," he commanded; "first slowly, then rapidly."
Again Hatch obeyed, while the scientist listened. And again he shook his
head. Then in turn every make of machine in the office was tested the
same way. At the end The Thinking Machine rose and went his way. There
was an expression nearly approaching complete bewilderment on his face.
For hour after hour that night The Thinking Machine half lay in a huge
chair in his laboratory, with eyes turned uncompromisingly upward, and
an expression of complete concentration on his face. There was no change
either in his position or his gaze as minute succeeded minute; the brow
was deeply wrinkled now, and the thin line of the lips was drawn taut.
The tiny clock in the reception room struck ten, eleven, twelve, and
finally one. At just half-past one The Thinking Machine rose suddenly.
"Positively I am getting stupid!" he grumbled half aloud. "Of course! Of
course! Why couldn't I have thought of that in the first place?..."
So it came about that Grayson did not go to his office on the following
morning at the usual time. Instead, he called again upon The Thinking
Machine in eager, expectant response to a note which had reached him at
his home just before he started to his office.
"Nothing yet," said The Thinking Machine as the financier entered. "But
here is something you must do today. At one o'clock," the scientist went
on, "you must issue orders for a gigantic deal of some sort; and you
must issue them precisely as you have issued them in the past; there
must be no variation. Dictate the letters as you have always done to
Miss Winthrop—but don't send them! When they come to you, keep them
until you see me."
"You mean that the deal must be purely imaginative?" inquired the
"Precisely," was the reply. "But make your instructions circumstantial;
give them enough detail to make them absolutely logical and convincing."
Grayson asked a dozen questions, answers to which were curtly denied,
then went to his office. The Thinking Machine again called Hatch on the
"I've got it," he announced briefly. "I want the best telegraph operator
you know. Bring him along and meet me in the room on the top floor where
the telephone is at precisely fifteen minutes before one o'clock
"Telegraph operator?" Hatch repeated.
"That's what I said—telegraph operator!" replied the scientist
Hatch smiled whimsically at the other end as he heard the receiver
banged on the hook—smiled because he knew the eccentric ways of this
singular man, whose mind so accurately illuminated every problem to
which it was directed. Then he went out to the telegraph room and
borrowed the principal operator. They were in the little room on the top
floor at precisely fifteen minutes of one.
The operator glanced about in astonishment. The room was still
unfurnished, save for the telephone box on the wall.
"What do I do?" he asked The Thinking Machine.
"I'll tell you when the time comes," responded the scientist, as he
glanced at his watch.
At three minutes of one o'clock he handed a sheet of blank paper to the
operator, and gave him final instructions.
There was ludicrous mystification on the operator's face; but he obeyed
orders, grinning cheerfully at Hatch as he tilted his cigar up to keep
the smoke out of his eyes. The Thinking Machine stood impatiently
looking on, watch in hand. Hatch didn't know what was happening, but he
At last the operator heard something. His face became suddenly alert. He
continued to listen for a moment, and then came a smile of recognition.
Less than ten minutes after Miss Winthrop had handed over the
typewritten letters of instruction to Grayson for signature, and while
he still sat turning them over in his hands, the door opened and The
Thinking Machine entered. He tossed a folded sheet of paper on the desk
before Grayson, and went straight to Miss Winthrop.
"So you did know Mr. Ralph Matthews after all?" he inquired.
The girl rose from her desk, and a flash of some subtle emotion passed
over her face. "What do you mean, sir?" she demanded.
"You might as well remove the silver box," The Thinking Machine went on
mercilessly. "There is no further need of the connection."
Miss Winthrop glanced down at the telephone extension on her desk, and
her hand darted toward it. The silver "vanity" box was directly under
the receiver, supporting it, so that all weight was removed from the
hook, and the line was open. She snatched the box and the receiver
dropped back on the hook. The Thinking Machine turned to Grayson.
"It was Miss Winthrop," he said.
"Miss Winthrop!" exclaimed Grayson, "I can't believe it!"
"Read the paper I gave you, Mr. Grayson," directed The Thinking Machine
coldly. "Perhaps that will enlighten her."
The financier opened the sheet, which had remained folded in his hand,
and glanced at what was written there. Slowly he read it aloud:
"Peabody—Sell ten thousand shares L. & W. at 97. McCracken Co.—Sell
ten thousand shares L. & W. at 97." He read on down the list,
bewildered. Then gradually, as he realized the import of what he read,
there came a hardening of the lines about his mouth.
"I understand, Miss Winthrop," he said at last. "This is the substance
of the orders I dictated, and in some way you made them known to persons
for whom they were not intended. I don't know how you did it, of course;
but I understand that you did do it, so——" He stepped to the door and
opened it with grave courtesy. "You may go now."
Miss Winthrop made no plea—merely bowed and went out. Grayson stood
staring after her for a moment, then turned to The Thinking Machine and
motioned him to a chair. "What happened?" he asked briskly.
"Miss Winthrop is a tremendously clever woman," replied The Thinking
Machine. "She neglected to tell you, however, that besides being a
stenographer and typist she is also a telegraph operator. She is so
expert in each of her lines that she combined the two, if I may say it
that way. In other words, in writing on the typewriter, she was clever
enough to be able to give the click of the machine the patterns in the
Morse telegraphic code—so that another telegraph operator at the other
end of the 'phone could hear her machine and translate the clicks into
Grayson sat staring at him incredulously. "I still don't understand," he
The Thinking Machine rose and went to Miss Winthrop's desk. "Here is an
extension telephone with the receiver on the hook. It happens that the
little silver box which you gave Miss Winthrop is just tall enough to
lift this receiver clear of the hook, and the minute the receiver is off
the hook the line is open. When you were at your desk and she was here,
you couldn't see this telephone; therefore it was a simple matter for
her to lift the receiver, and place the silver box underneath, thus
holding the line open permanently. That being true, the sound of the
typewriter—the striking of the keys—would go over the open wire to
whoever was listening at the other end. Then, if the striking of the
keys typed out your letters and, by their frequency and pauses,
simultaneously tapped out telegraphic code, an outside operator could
read your letters at the same moment they were being written. That is
all. It required extreme concentration on Miss Winthrop's part to type
accurately in Morse rhythms."
"Oh, I see!" exclaimed Grayson.
"When I knew that the leak in your office was not in the usual way,"
continued The Thinking Machine, "I looked for the unusual. There is
nothing very mysterious about it now—it was merely clever."
"Clever!" repeated Grayson, and his jaws snapped. "It is more than that.
Why, it's criminal! She should be prosecuted."
"I shouldn't advise that, Mr. Grayson," returned the scientist coldly.
"If it is honest—merely business—to juggle stocks as you told me you
did, this is no more dishonest. And besides, remember that Miss Winthrop
is backed by the people who have made millions out of you, and—well, I
wouldn't prosecute. It is betrayal of trust, certainly; but—" He rose
as if that were all, and started toward the door. "I would advise you,
however, to discharge the person who operates your switchboard."
"Was she in the scheme, too?" demanded Grayson. He rushed out of the
private office into the main office. At the door he met a clerk coming
"Where is Miss Mitchell?" demanded the financier hotly.
"I was just coming to tell you that she went out with Miss Winthrop just
now without giving any explanation," replied the clerk.
"Good day, Mr. Grayson," said The Thinking Machine.
The financier nodded his thanks, then stalked back into his room.
In the course of time The Thinking Machine received a check for ten
thousand dollars, signed, "J. Morgan Grayson." He glared at it for a
little while, then indorsed it in a crabbed hand, Pay to the Trustees'
Home for Crippled Children, and sent Martha, his housekeeper, out to