The Mammoth Book of Locked-Room Mysteries And Impossible Crimes

THE MOTOR BOAT by Jacques Futrelle

One of the many tragedies linked with the sinking of the Titanic was the death of author Jacques Futrelle(1875-1912). Futrelle was the creator of Professor S.F.X. Van Dusen, better known as “The Thinking Machine” because of his remarkable grasp of logic and deduction in solving apparently impossible crimes. Van Dusen came to prominence in one of the best known of all locked-room mysteries, “The Problem of Cell 13”, serialised in The Boston American in 1905. Dusen claimed that he could escape from a locked cell in the strongest prison kept under constant watch. The story was run as a contest to see if anyone could come up with the solution. The way in which Futrelle achieves his escape is perhaps the most ingenious in all fiction. I have not selected that story here, partly because it is almost constantly in print in some book or another, but mostly because it is not a crime story, but an extremely clever challenge. After this story Dusen is consulted, usually by newspaper reporter Hutchinson Hatch, on all manner of bizarre and seemingly impossible crimes. The following story, which first appeared in the Sunday Magazine (9 September 1906) is much less well known, though it is wonderfully bizarre.

Captain Hank Barber, master mariner, gripped the bow-rail of the Liddy Ann and peered off through the semi-fog of the early morning at a dark streak slashing along through the grey-green waters. It was a motor boat of long, graceful lines; and a single figure, that of a man, sat upright at her helm staring uncompromisingly ahead. She nosed through a roller, staggered a little, righted herself and sped on as a sheet of spray swept over her. The helmsman sat motionless, heedless of the stinging splash of wind-driven water in his face.

“She sure is a-goin’ some,” remarked Captain Hank, reflectively. “By Ginger! If she keeps it up into Boston Harbor, she won’t stop this side o’ the Public Gardens.”

Captain Hank watched the boat curiously until she was swallowed up, lost in the mist, then turned to his own affairs. He was a couple of miles out of Boston Harbor, going in; it was six o’clock of a grey morning. A few minutes after the disappearance of the motor boat Captain Hank’s attention was attracted by the hoarse shriek of a whistle two hundred yards away. He dimly traced through the mist the gigantic lines of a great vessel – it seemed to be a ship of war.

It was only a few minutes after Captain Hank lost sight of the motor boat that she was again sighted, this time as she flashed into Boston Harbor at full speed. She fled past, almost under the prow of a pilot boat, going out, and was hailed. At the mess table later the pilot’s man on watch made a remark about her.

“Goin’! Well, wasn’t she though! Never saw one thing pass so close to another in my life without scrubbin’ the paint offen it. She was so close up I could spit in her, and when I spoke the feller didn’t even look up – just kept a-goin’. I told him a few things that was good for his soul.”

Inside Boston Harbor the motor boat performed a miracle. Pursuing a course which was singularly erratic and at a speed more than dangerous she reeled on through the surge of the sea regardless alike of fog, the proximity of other vessels and the heavy wash from larger craft. Here she narrowly missed a tug; there she skimmed by a slow-moving tramp and a warning shout was raised; a fisherman swore at her as only a fisherman can. And finally when she passed into a clear space, seemingly headed for a dock at top speed, she was the most unanimously damned craft that ever came into Boston Harbor.

“Guess that’s a through boat,” remarked an aged salt, facetiously as he gazed at her from a dock. “If that durned fool don’t take some o’the speed offen her she’ll go through all right – wharf an’ all.”

Still the man in the boat made no motion; the whizz of her motor, plainly heard in a sudden silence, was undiminished. Suddenly the tumult of warning was renewed. Only a chance would prevent a smash. Then Big John Dawson appeared on the string piece of the dock. Big John had a voice that was noted from Newfoundland to Norfolk for its depth and width, and possessed objurgatory powers which were at once the awe and admiration of the fishing fleet.

“You ijit!” he bellowed at the impassive helmsman. “Shut off that power an’ throw yer helium.”

There was no response; the boat came on directly toward the dock where Big John and his fellows were gathered. The fishermen and loungers saw that a crash was coming and scattered from the string piece.

“The durned fool,” said Big John, resignedly.

Then came the crash, the rending of timbers, and silence save for the grinding whir of the motor. Big John ran to the end of the wharf and peered down. The speed of the motor had driven the boat half way upon a float which careened perilously. The man had been thrown forward and lay huddled up face downward and motionless on the float. The dirty water lapped at him greedily.

Big John was the first man on the float. He crept cautiously to the huddled figure and turned it face upward. He gazed for an instant into wide staring eyes then turned to the curious ones peering down from the dock.

“No wonder he didn’t stop,” he said in an awed tone. “The durned fool is dead.”

Willing hands gave aid and after a minute the lifeless figure lay on the dock. It was that of a man in uniform – the uniform of a foreign navy. He was apparently forty-five years old, large and powerful of frame with the sun-browned face of a seaman. The jet black of moustache and goatee was startling against the dead colour of the face. The hair was tinged with grey; and on the back of the left hand was a single letter – “D” – tattooed in blue.

“He’s French,” said Big John authoritatively, “an’ that’s the uniform of a Cap’n in the French Navy.” He looked puzzled a moment as he stared at the figure. “An’ they ain’t been a French man-o’-war in Boston Harbor for six months.”

After awhile the police came and with them Detective Mallory, the big man of the Bureau of Criminal Investigation; and finally Dr Clough, Medical Examiner. While the detective questioned the fishermen and those who had witnessed the crash, Dr Clough examined the body.

“An autopsy will be necessary,” he announced as he arose.

“How long has he been dead?” asked the detective.

“Eight or ten hours, I should say. The cause of death doesn’t appear. There is no shot or knife wound so far as I can see.”

Detective Mallory closely examined the dead man’s clothing. There was no name or tailor mark; the linen was new; the name of the maker of the shoes had been ripped out with a knife. There was nothing in the pockets, not a piece of paper or even a vagrant coin.

Then Detective Mallory turned his attention to the boat. Both hull and motor were of French manufacture. Long, deep scratches on each side showed how the name had been removed. Inside the boat the detective saw something white and picked it up. It was a handkerchief – a woman’s handkerchief, with the initials “E.M.B.” in a corner.

“Ah, a woman’s in it!” he soliloquized.

Then the body was removed and carefully secluded from the prying eyes of the press. Thus no picture of the dead man appeared. Hutchinson Hatch, reporter, and others asked many questions. Detective Mallory hinted vaguely at international questions – the dead man was a French officer, he said, and there might be something back of it.

“I can’t tell you all of it,” he said wisely, “but my theory is complete. It is murder. The victim was captain of a French man-of-war. His body was placed in a motor boat, possibly a part of the fittings of the warship and the boat set adrift. I can say no more.”

“Your theory is complete then,” Hatch remarked casually, “except the name of the man, the manner of death, the motive, the name of his ship, the presence of the handkerchief and the precise reason why the body should be disposed of in this fashion instead of being cast into the sea.”

The detective snorted. Hatch went away to make some inquiries on his own account. Within half a dozen hours he had satisfied himself by telegraph that no French was craft had been within five hundred miles of Boston for six months. Thus the mystery grew deeper; a thousand questions to which there seemed no answer arose.

At this point, the day following the events related, the problem of the motor boat came to the attention of Professor Augustus S.F.X. Van Dusen, The Thinking Machine. The scientist listened closely but petulantly to the story Hatch told.

“Has there been an autopsy yet?” he asked at last.

“It is set for eleven o’clock today,” replied the reporter. “It is now after ten.”

“I shall attend it,” said the scientist.

Medical Examiner Clough welcomed the eminent Professor Van Dusen’s proffer of assistance in his capacity of MD, while Hatch and other reporters impatiently cooled their toes on the curb. In two hours the autopsy had been completed. The Thinking Machine amused himself by studying the insignia on the dead man’s uniform, leaving it to Dr Clough to make a startling statement to the press. The man had not been murdered; he had died of heart failure. There was no poison in the stomach, nor was there a knife or pistol wound.

Then the inquisitive press poured in a flood of questions. Who had scratched off the name of the boat? Dr Clough didn’t know. Why had it been scratched off? Still he didn’t know. How did it happen that the name of the maker of the shoes had been ripped out? He shrugged his shoulders. What did the handkerchief have to do with it? Really he couldn’t conjecture. Was there any inkling of the dead man’s identity? Not so far as he knew. Any scar on the body which might lead to identification? No.

Hatch made a few mental comments on officials in general and skilfully steered The Thinking Machine away from the other reporters.

“Did that man die of heart failure?” he asked, flatly.

“He did not,” was the curt reply. “It was poison.”

“But the Medical Examiner specifically stated that there was no poison in the stomach,” persisted the reporter.

The scientist did not reply. Hatch struggled with and suppressed a desire to ask more questions. On reaching home the scientist’s first act was to consult an encyclopedia. After several minutes he turned to the reporter with an inscrutable face.

“Of course the idea of a natural death in this case is absurd,” he said, shortly. “Every fact is against it. Now, Mr Hatch, please get for me all the local and New York newspapers of the day the body was found – not the day after. Send or bring them to me, then come again at five this afternoon.”

“But – but -” Hatch blurted.

“I can say nothing until I know all the facts,” interrupted The Thinking Machine.

Hatch personally delivered the specified newspapers into the hands of The Thinking Machine – this man who never read newspapers – and went away. It was an afternoon of agony; an agony of impatience. Promptly at five o’clock he was ushered into Professor Van Dusen’s laboratory. The scientist sat half smothered in newspapers, and popped up out of the heap aggressively.

“It was murder, Mr Hatch,” he exclaimed, suddenly. “Murder by an extraordinary method.”

“Who – who is the man? How was he killed?” asked Hatch.

“His name is-” the scientist began, then paused. “I presume your office has the book Who’s Who In America? Please ’phone and ask them to give you the record of Langham Dudley.”

“Is he the dead man?” Hatch demanded quickly.

“I don’t know,” was the reply.

Hatch went to the telephone. Ten minutes later he returned to find The Thinking Machine dressed to go out.

“Langham Dudley is a ship owner, fifty-one years old,” the reporter read from notes he had taken. “He was once a sailor before the mast and later became a ship owner in a small way. He was successful in his small undertakings and for fifteen years has been a millionaire. He has a certain social position, partly through his wife whom he married a year and a half ago. She was Edith Marston Belding, a daughter of the famous Belding family. He has an estate on the North Shore.”

“Very good,” commented the scientist. “Now we will find out something about how this man was killed.”

At North Station they took train for a small place on the North Shore, thirty-five miles from Boston. There The Thinking Machine made some inquiries and finally they entered a lumber-some carry-all. After a drive of half an hour through the dark they saw the lights of what seemed to be a pretentious country place. Somewhere off to the right Hatch heard the roar of the restless ocean.

“Wait for us,” commanded The Thinking Machine as the carry-all stopped.

The Thinking Machine ascended the steps, followed by Hatch, and rang. After a minute or so the door was opened and the light flooded out. Standing before them was a Japanese – a man of indeterminate age with the graven face of his race.

“Is Mr Dudley in?” asked The Thinking Machine.

“He has not that pleasure,” replied the Japanese, and Hatch smiled at the queerly turned phrase.

“Mrs Dudley?” asked the scientist.

“Mrs Dudley is attiring herself in clothing,” replied the Japanese. “If you will be pleased to enter.”

The Thinking Machine handed him a card and was shown into a reception room. The Japanese placed chairs for them with courteous precision and disappeared. After a short pause there was a rustle of silken skirts on the stairs, and a woman – Mrs Dudley – entered. She was not pretty; she was stunning rather, tall, of superb figure and crowned with a glory of black hair.

“Mr Van Dusen?” she asked as she glanced at the card.

The Thinking Machine bowed low, albeit awkwardly. Mrs Dudley sank down on a couch and the two men resumed their seats. There was a little pause; Mr Dudley broke the silence at last.

“Well, Mr Van Dusen, if you -” she began.

“You have not seen a newspaper for several days?” asked The Thinking Machine, abruptly.

“No,” she replied, wonderingly, almost smiling. “Why?”

“Can you tell me just where your husband is?”

The Thinking Machine squinted at her in that aggressive way which was habitual. A quick flush crept into her face, and grew deeper at the sharp scrutiny. Inquiry lay in her eyes.

“I don’t know,” she replied at last. “In Boston, I presume.”

“You haven’t seen him since the night of the ball?”

“No. I think it was half past one o’clock that night.”

“Is his motor boat here?”

“Really, I don’t know. I presume it is. May I ask the purpose of this questioning?”

The Thinking Machine squinted hard at her for half a minute. Hatch was uncomfortable, half resentful even, at the agitation of the woman and the sharp, cold tone of his companion.

“On the night of the ball,” the scientist went on, passing the question, “Mr Dudley cut his left arm just above the wrist. It was only a slight wound. A piece of court plaster was put on it. Do you know if he put it on himself? If not, who did?”

“I put it on,” replied Mrs Dudley, unhesitatingly, wonderingly.

“And whose court plaster was it?”

“Mine – some I had in my dressing room. Why?”

The scientist arose and paced across the floor, glancing once out the hall door. Mrs Dudley looked at Hatch inquiringly and was about to speak when The Thinking Machine stopped beside her and placed his slim fingers on her wrist. She did not resent the action; was only curious if one might judge from her eyes.

“Are you prepared for a shock?” the scientist asked.

“What is it?” she demanded in sudden terror. “This suspense-”

“Your husband is dead – murdered – poisoned!” said the scientist with sudden brutality. His fingers still lay on her pulse. “The court plaster which you put on his arm and which came from your room was covered with a virulent poison which was instantly transfused into his blood.”

Mrs. Dudley did not start or scream. Instead she stared up at The Thinking Machine a moment, her face became pallid, a little shiver passed over her. Then she fell back on the couch in a dead faint.

“Good!” remarked The Thinking Machine complacently. And then as Hatch started up suddenly: “Shut that door,” he commanded.

The reporter did so. When he turned back, his companion was leaning over the unconscious woman. After a moment he left her and went to a window where he stood looking out. As Hatch watched he saw the color coming back into Mrs Dudley’s face. At last she opened her eyes.

“Don’t get hysterical,” The Thinking Machine directed calmly. “I know you had nothing whatever to do with your husband’s death. I want only a little assistance to find out who killed him.”

“Oh, my God!” exclaimed Mrs Dudley. “Dead! Dead!”

Suddenly tears leaped from her eyes and for several minutes the two men respected her grief. When at last she raised her face her eyes were red, but there was a rigid expression about the mouth.

“If I can be of any service-” she began.

“Is this the boat house I see from this window?” asked The Thinking Machine. “That long, low building with the light over the door?”

“Yes,” replied Mrs Dudley.

“You say you don’t know if the motor boat is there now?”

“No, I don’t.”

“Will you ask your Japanese servant, and if he doesn’t know, let him go see, please?”

Mrs Dudley arose and touched an electric button. After a moment the Japanese appeared at the door.

“Osaka, do you know if Mr Dudley’s motor boat is in the boat house?” she asked.

“No, honourable lady.”

“Will you go yourself and see?”

Osaka bowed low and left the room, closing the door gently behind him. The Thinking Machine again crossed to the window and sat down staring out into the night. Mrs Dudley asked questions, scores of them, and he answered them in order until she knew the details of the finding of her husband’s body – that is, the details the public knew. She was interrupted by the reappearance of Osaka.

“I do not find the motor boat in the house, honourable lady.”

“That is all,” said the scientist.

Again Osaka bowed and retired.

“Now, Mrs Dudley,” resumed The Thinking Machine almost gently, “we know your husband wore a French naval costume at the masked ball. May I ask what you wore?”

“It was a Queen Elizabeth costume,” replied Mrs Dudley, “very heavy with a long train.”

“And if you could give me a photograph of Mr Dudley?”

Mrs Dudley left the room an instant and returned with a cabinet photograph. Hatch and the scientist looked at it together; it was unmistakably the man in the motor boat.

“You can do nothing yourself,” said The Thinking Machine at last, and he moved as if to go. “Within a few hours we will have the guilty person. You may rest assured that your name will be in no way brought into the matter unpleasantly.”

Hatch glanced at his companion; he thought he detected a sinister note in the soothing voice, but the face expressed nothing. Mrs Dudley ushered them into the hall; Osaka stood at the front door. They passed out and the door closed behind them.

Hatch started down the steps but The Thinking Machine stopped at the door and tramped up and down. The reporter turned back in astonishment. In the dim reflected light he saw the scientist’s finger raised, enjoining silence, then saw him lean forward suddenly with his ear pressed to the door. After a little he rapped gently. The door was opened by Osaka, who obeyed a beckoning motion of the scientist’s hand and came out. Silently he was led off the veranda into the yard; he appeared in no way surprised.

“Your master, Mr Dudley, has been murdered,” declared The Thinking Machine quietly, to Osaka. “We know that Mrs Dudley killed him,” he went on as Hatch stared, “but I have told her she is not suspected. We are not officers and cannot arrest her. Can you go with us to Boston, without the knowledge of anyone here and tell what you know of the quarrel between husband and wife to the police?”

Osaka looked placidly into the eager face.

“I had the honour to believe that the circumstances would not be recognized,” he said finally. “Since you know, I will go.”

“We will drive down a little way and wait for you.”

The Japanese disappeared into the house again. Hatch was too astounded to speak, but followed The Thinking Machine into the carry-all. It drove away a hundred yards and stopped. After a few minutes an impalpable shadow came toward them through the night. The scientist peered out as it came up.

“Osaka?” he asked softly.

“Yes.”

An hour later the three men were on a train, Boston bound. Once comfortably settled the scientist turned to the Japanese.

“Now if you will please tell me just what happened the night of the ball?” he asked, “and the incidents leading up to the disagreement between Mr and Mrs Dudley?”

“He drank elaborately,” Osaka explained reluctantly, in his quaint English, “and when drinking he was brutal to the honourable lady. Twice with my own eyes I saw him strike her – once in Japan where I entered his service while they were on a wedding journey, and once here. On the night of the ball he was immeasurably intoxicated, and when he danced, he fell down to the floor. The honourable lady was chagrined and angry – she had been angry before. There was some quarrel which I am not comprehensive of. They had been widely divergent for several months. It was, of course, not prominent in the presence of others.”

“And the cut on his arm where the court plaster was applied?” asked the scientist. “Just how did he get that?”

“It was when he fell down,” continued the Japanese. “He reached to embrace a carved chair and the carved wood cut his arm. I assisted him to his feet and the honourable lady sent me to her room to get court plaster. I acquired it from her dressing table and she placed it on the cut.”

“That makes the evidence against her absolutely conclusive,” remarked The Thinking Machine, as if finally. There was a little pause, and then: “Do you happen to know just how Mrs Dudley placed the body in the boat?”

“I have not that honour,” said Osaka. “Indeed I am not comprehensive of anything that happened after the court plaster was put on except that Mr Dudley was affected some way and went out of the house. Mrs Dudley, too, was not in the ball room for ten minutes or so afterwards.”

Hutchinson Hatch stared frankly into the face of The Thinking Machine; there was nothing to be read there. Still deeply thoughtful Hatch heard the brakeman bawl “Boston” and mechanically followed the scientist and Osaka out of the station into a cab. They were driven immediately to Police Headquarters. Detective Mallory was just about to go home when they entered his office.

“It may enlighten you, Mr Mallory,” announced the scientist coldly, “to know that the man in the motor boat was not a French naval officer who died of natural causes – he was Langham Dudley, a millionaire ship owner. He was murdered. It just happens that I know the person who did it.”

The detective arose in astonishment and stared at the slight figure before him inquiringly; he knew the man too well to dispute any assertion he might make.

“Who is the murderer?” he asked.

The Thinking Machine closed the door and the spring lock clicked.

“That man there,” he remarked calmly, turning on Osaka.

For one brief moment there was a pause and silence; then the detective advanced upon the Japanese with hand outstretched. The agile Osaka leapt suddenly, as a snake strikes; there was a quick, fierce struggle and Detective Mallory sprawled on the floor. There had been just a twist of the wrist – a trick of jiu jitsu – and Osaka had flung himself at the locked door. As he fumbled there, Hatch, deliberately and without compunction, raised a chair and brought it down on his head. Osaka sank down without a sound.

It was an hour before they brought him around again. Meanwhile the detective had patted and petted half a dozen suddenly acquired bruises, and had then searched Osaka. He found nothing to interest him save a small bottle. He uncorked it and started to smell it when The Thinking Machine snatched it away.

“You fool, that’ll kill you!” he exclaimed.

Osaka sat, lashed hand and foot to a chair, in Detective Mallory’s office – so placed by the detective for safe keeping. His face was no longer expressionless; there were fear and treachery and cunning there. So he listened, perforce, to the statement of the case by The Thinking Machine who leaned back in his chair, squinting steadily upward and with his long, slender fingers pressed together.

“Two and two make four, not sometimes but all the time,” he began at last as if disputing some previous assertion. “As the figure ‘two,’ wholly disconnected from any other, gives small indication of a result, so is an isolated fact of little consequence. Yet that fact added to another, and the resulting fact added to a third, and so on, will give a final result. That result, if every fact is considered, must be correct. Thus any problem may be solved by logic; logic is inevitable.

“In this case the facts, considered singly, might have been compatible with either a natural death, suicide or murder – considered together they proved murder. The climax of this proof was the removal of the maker’s name from the dead man’s shoes, and a fact strongly contributory was the attempt to destroy the identity of the boat. A subtle mind lay back of it all.”

“I so regarded it,” said Detective Mallory. “I was confident of murder until the Medical Examiner-”

“We prove a murder,” The Thinking Machine went on serenely. “The method? I was with Dr Clough at the autopsy. There was no shot, or knife wound, no poison in the stomach. Knowing there was murder I sought further. Then I found the method in a slight, jagged wound on the left arm. It had been covered with court plaster. The heart showed constriction without apparent cause, and while Dr Clough examined it I took off this court plaster. Its odour, an unusual one, told me that poison had been transfused into the blood through the wound. So two and two had made four.

“Then – what poison? A knowledge of botany aided me. I recognized faintly the trace of an odour of an herb which is not only indigenous to, but grows exclusively in Japan. Thus a Japanese poison. Analysis later in my laboratory proved it was a Japanese poison, virulent, and necessarily slow to act unless it is placed directly in an artery. The poison on the court plaster and that you took from Osaka is identical.”

The scientist uncorked the bottle and permitted a single drop of a green liquid to fall on his handkerchief. He allowed a minute or more for evaporation then handed it to Detective Mallory who sniffed at it from a respectful distance. Then The Thinking Machine produced the bit of court plaster he had taken from the dead man’s arm, and again the detective sniffed.

“The same,” the scientist resumed as he touched a lighted match to the handkerchief and watched it crumble to ashes, “and so powerful that in its pure state mere inhalation is fatal. I permitted Dr Clough to make public his opinion – heart failure – after the autopsy for obvious reasons. It would reassure the murderer for instance if he saw it printed, and besides Dudley did die from heart failure; the poison caused it.

“Next came identification. Mr Hatch learned that no French warship had been within hundreds of miles of Boston for months. The one seen by Captain Barber might have been one of our own. This man was supposed to be a French naval officer, and had been dead less than eight hours. Obviously he did not come from a ship of his own country. Then from where?

“I know nothing of uniforms, yet I examined the insignia on the arms and shoulders closely after which I consulted my encyclopedia. I learned that while the uniform was more French than anything else, it was really the uniform of no country, because it was not correct. The insignia were mixed.

“Then what? There were several possibilities, among them a fancy dress ball was probable. Absolute accuracy would not be essential there. Where had there been a fancy dress ball? I trusted to the newspapers to tell me that. They did. A short dispatch from a place on the North Shore stated that on the night before the man was found dead there had been a fancy dress ball at the Langham Dudley estate.

“Now it is as necessary to remember every fact in solving a problem as it is to consider every figure in arithmetic. Dudley! Here was the ‘D’ tattooed on the dead man’s hand. Who’s Who showed that Langham Dudley married Edith Marston Belding. Here was the ‘E.M.B.’ on the handkerchief in the boat. Langham Dudley was a ship owner had been a sailor, was a millionaire. Possibly this was his own boat built in France.”

Detective Mallory was staring into the eyes of The Thinking Machine in frank admiration; Osaka to whom the narrative had thus far been impersonal, gazed, gazed as if fascinated. Hutchinson Hatch, reporter, was drinking in every word greedily.

“We went to the Dudley place,” the scientist resumed after a moment. “This Japanese opened the door. Japanese poison! Two and two were still making four. But I was first interested in Mrs Dudley. She showed no agitation and told me frankly that she placed the court plaster on her husband’s arm, and that it came from her room. There was instantly a doubt as to her connection with the murder; her immediate frankness aroused it.

“Finally, with my hand on her pulse – which was normal – I told her as brutally as I could that her husband had been murdered. Her pulse jumped frightfully and as I told her the cause of death it wavered, weakened and she fainted. Now if she had known her husband was dead – even if she had killed him – a mere statement of his death would not have caused that pulse. Further I doubt if she could have disposed of her husband’s body in the motor boat. He was a large man and the manner of her dress even, was against this. Therefore she was innocent.

“And then? The Japanese, Osaka, here. I could see the door of the boat house from the room where we were. Mrs Dudley asked Osaka if Mr Dudley’s boat were in the house. He said he didn’t know. Then she sent him to see. He returned and said the boat was not there, yet he had not gone to the boat house at all. Ergo, he knew the boat was not there. He may have learned it from another servant, still it was a point against him.”

Again the scientist paused and squinted at the Japanese. For a moment Osaka withstood the gaze, then his eyes shifted and he moved uncomfortably.

“I tricked Osaka into coming here by a ludicrously simple expedient,” The Thinking Machine went on steadily. “On the train I asked if he knew just how Mrs Dudley got the body of her husband into the boat. Remember at this point he was not supposed to know that the body had been in a boat at all. He said he didn’t know and by that very answer admitted that he knew the body had been placed in the boat. He knew because he put it there himself. He didn’t merely throw it in the water because he had sense enough to know if the tide didn’t take it out, it would rise, and possibly be found.

“After the slight injury Mr Dudley evidently wandered out toward the boat house. The poison was working, and perhaps he fell. Then this man removed all identifying marks, even to the name in the shoes, put the body in the boat and turned on full power. He had a right to assume that the boat would be lost, or that the dead man would be thrown out. Wind and tide and a loose rudder brought it into Boston Harbor. I do not attempt to account for the presence of Mrs Dudley’s handkerchief in the boat. It might have gotten there in one of a hundred ways.”

“How did you know husband and wife had quarrelled?” asked Hatch.

“Surmise to account for her not knowing where he was,” replied The Thinking Machine. “If they had had a violent disagreement it was possible that he would have gone away without telling her, and she would not have been particularly worried, at least up to the time we saw her. As it was, she presumed he was in Boston; perhaps Osaka here gave her that impression?”

The Thinking Machine turned and stared at the Japanese curiously.

“Is that correct?” he asked.

Osaka did not answer.

“And the motive?” asked Detective Mallory, at last.

“Will you tell us just why you killed Mr Dudley?” asked The Thinking Machine of the Japanese.

“I will not,” exclaimed Osaka, suddenly. It was the first time he had spoken.

“It probably had to do with a girl in Japan,” explained The Thinking Machine, easily. “The murder had been a long cherished project, such a one as revenge through love would have inspired.”

It was a day or so later that Hutchinson Hatch called to inform The Thinking Machine that Osaka had confessed and had given the motive for the murder. It was not a nice story.

“One of the most astonishing things to me,” Hatch added, “is the complete case of circumstantial evidence against Mrs Dudley, beginning with the quarrel and leading to the application of the poison with her own hands. I believe she would have been convicted on the actual circumstantial evidence had you not shown conclusively that Osaka did it.”

“Circumstantial fiddlesticks!” snapped The Thinking Machine. “I wouldn’t convict a dog of stealing jam on circumstantial evidence alone, even if he had jam all over his nose.” He squinted truculently at Hatch for a moment. “In the first place well behaved dogs don’t eat jam,” he added more mildly.