for the third time professor augustus s. f. x. van dusen — so-called the thinking machine — read the letter. it was spread out in front of him on the table, and his blue eyes were narrowed to mere slits as he studied it through his heavy eyeglasses. the young woman who had placed the letter in his hands, miss elizabeth devan, sat waiting patiently on the sofa in the little reception room of the thinking machine’s house. her blue eyes were opened wide and she stared as if fascinated at this man who had become so potent a factor in the solution of intangible mysteries.

here is the letter:

to those concerned:

tired of it all i seek the end, and am content. ambition now is dead; the grave yawns greedily at my feet, and with the labor of my own hands lost i greet death of my own will, by my own act. to my son i leave all, and you who maligned me, you who discouraged me, you may read this and know i punish you thus. it’s for him, my son, to forgive. i dared in life and dare dead your everlasting anger, not alone that you didn’t speak but that you cherished secret, and my ears are locked forever against you. my vault is my resting place. on the brightest and dearest page of life i wrote (7) my love for him. family ties, binding as the bible itself, bade me give all to my son.

good-bye. i die.

pomeroy stockton

“under just what circumstances did this letter come into your possession, miss devan?” the thinking machine asked. “tell me the full story; omit nothing.”

the scientist sank back into his chair with his enormous yellow head pillowed comfortably against the cushion and his long, steady fingers pressed tip to tip. he didn’t even look at his pretty visitor. she had come to ask for information; he was willing to give it, because it offered another of those abstract problems which he always found interesting. in his own field — the sciences — his fame was worldwide. this concentration of a brain which had achieved so much on more material things was perhaps a sort of relaxation.

miss devan had a soft, soothing voice, and as she talked it was broken at times by what seemed to be a sob. her face was flushed a little, and she emphasized her points by a quick clasping and unclasping of her daintily gloved hands.

“my father, or rather my adopted father, pomeroy stockton, was an inventor,” she began. “we lived in a great, old-fashioned house in dorchester. we have lived there since i was a child. when i was only five or six years old, i was left an orphan and was adopted by mr. stockton, then a man of forty years. i am now twenty-three. i was raised and cared for by mr. stockton, who always treated me as a daughter. his death, therefore, was a great blow to me.

“mr. stockton was a widower with only one child of his own, a son, john stockton, who is now about thirty one years old. he is a man of irreproachable character, and has always, since i first knew him, been religiously inclined. he is the junior partner in a great commercial company, dutton & stockton, leather men. i suppose he has an immense fortune, for he gives largely to charity, and is, too, the active head of a large sunday school.

“pomeroy stockton, my adopted father, almost idolized this son, although there was in his manner toward him something akin to fear. close work had made my father querulous and irritable. yet i don’t believe a better hearted man ever lived. he worked most of the time in a little shop, which he had installed in a large back room on the ground floor of the house. he always worked with the door locked. there were furnaces, moulds, and many things that i didn’t know the use of.”

“i know who he was,” said the thinking machine. “he was working to rediscover the secret of hardened copper — a secret which was lost in egypt. i knew mr. stockton very well by reputation. go on.”

“whatever it was he worked on,” miss devan resumed, “he guarded it very carefully. he would permit no one at all to enter the room. i have never seen more than a glimpse of what was in it. his son particularly i have seen barred out of the shop a dozen times and every time there was a quarrel to follow.

“those were the conditions at the time mr. stockton first became ill, six or seven months ago. at that time he double locked the doors of his shop, retired to his rooms on the second floor, and remained there in practical seclusion for two weeks or more. these rooms adjoined mine, and twice during that time i heard the son and the father talking loudly, as if quarreling. at the end of the two weeks, mr. stockton returned to work in the shop and shortly afterward the son, who had also lived in the house, took apartments in beacon street and removed his belongings from the house.

“from that time up to last monday — this is thursday — i never saw the son in the house. on monday the father was at work as usual in the shop. he had previously told me that the work he was engaged in was practically ended and he expected a great fortune to result from it. about 5 o’clock in the afternoon on monday the son came to the house. no one knows when he went out. it is a fact, however, that father did not have dinner at the usual time, 6:30. i presumed he was at work, and did not take time for his dinner. i have known him to do this many times.”

for a moment the girl was silent and seemed to be struggling with some deep grief which she could not control.

“and next morning?” asked the thinking machine gently.

“next morning,” the girl went on, “father was found dead in the workshop. there were no marks on his body, nothing to indicate at first the manner of death. it was as if he had sat in his chair beside one of the furnaces and had taken poison and died at once. a small bottle of what i presume to be prussic acid was smashed on the floor, almost beside his chair. we discovered him dead after we had rapped on the door several times and got no answer. then montgomery, our butler, smashed in the door, at my request. there we found father.

“i immediately telephoned to the son, john stockton, and he came to the house. the letter you now have was found in my father’s pocket. it was just as you see it. mr. stockton seemed greatly agitated and started to destroy the letter. i induced him to give it to me, because instantly it occurred to me that there was something wrong about all of it. my father had talked too often to me about the future, what he intended to do and his plans for me. there may not be anything wrong. the letter may be just what it purports to be. i hope it is — oh — i hope it is. yet everything considered —”

“was there an autopsy?” asked the thinking machine.

“no. john stockton’s actions seemed to be directed against any investigation. he told me he thought he could do certain things which would prevent the matter coming to the attention of the police. my father was buried on a death certificate issued by a dr. benton, who has been a friend of john stockton since their college days. in that way the appearance of suicide or anything else was covered up completely.

“both before and after the funeral john stockton made me promise to keep this letter hidden or else destroy it. in order to put an end to this i told him i had destroyed the letter. this attitude on his part, the more i thought of it, seemed to confirm my original idea that it had not been suicide. night after night i thought of this, and finally decided to come to you rather than to the police. i feel that there is some dark mystery behind it all. if you can help me now —”

“yes, yes,” broke in the thinking machine. “where was the key to the workshop? in pomeroy’s pocket? in his room? in the door?”

“really, i don’t know,” said miss devan. “it hadn’t occurred to me.”

“did mr. stockton leave a will?”

“yes, it is with his lawyer, a mr. sloane.”

“has it been read? do you know what is in it?”

“it is to be read in a day or so. judging from the second paragraph of the letter, i presume he left everything to his son.”

for the fourth time the thinking machine read the letter. at its end he again looked up at miss devan.

“just what is your interpretation of this letter from one end to the other?” he asked.

“speaking from my knowledge of mr. stockton and the circumstances surrounding him,” the girl explained, “i should say the letter means just what it says. i should imagine from the first paragraph that something he invented had been taken away from him, stolen perhaps. the second paragraph and the third, i should say, were intended as a rebuke to certain relatives — a brother and two distant cousins — who had always regarded him as a crank and took frequent occasion to tell him so. i don’t know a great deal of the history of that other branch of the family. the last two paragraphs explain themselves except —”

“except the figure seven,” interrupted the scientist. “do you have any idea whatever as to the meaning of that?”

the girl took the letter and studied it closely for a moment.

“not the slightest,” she said. “it does not seem to be connected with anything else in the letter.”

“do you think it possible, miss devan, that this letter was written under coercion?”

“i do,” said the girl quickly, and her face flamed. “that’s just what i do think. from the first i have imagined some ghastly, horrible mystery back of it all.”

“or, perhaps pomeroy stockton never saw this letter at all,” mused the thinking machine. “it may be a forgery?”

“forgery!” gasped the girl. “then john stockton —”

“whatever it is, forged or genuine,” the thinking machine went on quietly, “it is a most extraordinary document. it might have been written by a poet. it states things in such a roundabout way. it is not directly to the point, as a practical man would have written.”

there was silence for several minutes and the girl sat leaning forward on the table, staring into the inscrutable eyes of the scientist.

“perhaps, perhaps,” she said, “there is a cipher of some sort in it?”

“that is precisely correct,” said the thinking machine emphatically. “there is a cipher in it, and a very ingenious one.”

2

it was twenty-four hours later that the thinking machine sent for hutchinson hatch, reporter, and talked over the matter with him. he had always found hatch a discreet, resourceful individual, who was willing to aid in any way in his power.

hatch read the letter, which the thinking machine had said contained a cipher, and then the circumstances as related by miss devan were retold to the reporter.

“do you think it is a cipher?” asked hatch in conclusion.

“it is a cipher,” replied the thinking machine. “if what miss devan has said is correct, john stockton cannot have said anything about the affair. i want you to go and talk to him, find out all about him and what division of the property is made by the will. does this will give everything to the son?

“also find out what personal enmity there is between john stockton and miss devan, and what was the cause of it. was there a man in it? if so, who? when you have done all this, go to the house in dorchester and bring me the family bible, if there is one there. it’s probably a big book. if it is not there, let me know immediately by ‘phone. miss devan will, i suppose, give it to you, if she has it.”

with these instructions hatch went away. half an hour later he was in the private office of john stockton at the latter’s place of business. mr. stockton was a man of long visage, rather angular and clerical in appearance. there was a smug satisfaction about the man that hatch didn’t quite approve of, and yet it was a trait which found expression only in a soft voice and small acts of needless courtesy.

a deprecatory look passed over stockton’s face when hatch asked the first question, which bore on his relationship with pomeroy stockton.

“i had hoped that this matter would not come to the attention of the press,” said stockton in an oily, gentle tone. “it is something which can only bring disgrace upon my poor father’s memory, and his has been a name associated with distinct achievements in the progress of the world. however, if necessary, i will state my knowledge of the affair, and invite the investigation which, frankly, i will say, i tried to stop.”

“how much was your father’s estate?” asked hatch.

“something more than a million,” was the reply. “he made most of it through a device for coupling cars. this is now in use on practically all the railroads.”

“and the division of this property by will?” asked hatch.

“i haven’t seen the will, but i understand that he left practically everything to me, settling an annuity and the home in dorchester on miss devan, whom he had always regarded as a daughter.”

“that would give you then, say, two-thirds or three-quarters of the estate.”

“something like that, possibly $800,000.”

“where is this will now?”

“i understand in the hands of my father’s attorney, mr. sloane.”

“when is it to be read?”

“it was to have been read today, but there has been some delay about it. the attorney postponed it for a few days.”

“what, mr. stockton, was the purpose in making it appear that your father died naturally, when obviously he committed suicide and there is even a suggestion of something else?” demanded hatch.

john stockton sat up straight in his chair with a startled expression in his eyes. he had been rubbing his hands together complacently; now he stopped and stared at the reporter.

“something else?” he asked. “pray what else?”

hatch shrugged his shoulders, but in his eyes there lay almost an accusation.

“did any motive ever appear for your father’s suicide?”

“i know of none,” stockton replied. “yet, admitting that this is suicide, without a motive, it seems that the only fault i have committed is that i had a friend report it otherwise and avoided a police inquiry.”

“it’s just that. why did you do it?”

“naturally to save the family name from disgrace. but this something else you spoke of? do you mean that anyone else thinks that anything other than suicide or natural death is possible?”

as he asked the question there came some subtle change over his face. he leaned forward toward the reporter. all trace of the sanctimonious smirk about the thin-lipped mouth had gone now.

“miss devan has produced the letter found on your father at death and has said —” began the reporter.

“elizabeth! miss devan!” exclaimed john stockton. he arose suddenly, paced several times across the room, then stopped in front of the reporter. “she gave me her word of honor that she would not make the existence of that letter known.”

“but she has made it public,” said hatch. “and further she intimates that your father’s death was not even what it appeared to be, suicide.”

“she’s crazy, man, crazy,” said stockton in deep agitation. “who could have killed my father? what motive could there have been?”

there was a grim twitching of hatch’s lips.

“was miss devan legally adopted by your father?” he asked, irrelevantly.

“yes.”

“in that event, disregarding other relatives, doesn’t it seem strange even to you that he gives three quarters of the estate to you — you have a fortune already — and only a small part to miss devan, who has nothing?”

“that’s my father’s business.”

there was a pause. stockton was still pacing back and forth.

finally he sank down in his chair at the desk, and sat for a moment looking at the reporter.

“is that all?” he asked.

“i should like to know, if you don’t mind telling me, what direct cause there is for ill feeling between miss devan and you?”

“there is no ill feeling. we merely never got along well together. my father and i have had several arguments about her for reasons which it is not necessary to go into.”

“did you have such an argument on the night before your father was found dead?”

“i believe there was something said about her.”

“what time did you leave the shop that night?”

“about 10 o’clock.”

“and you had been in the room with your father since afternoon, had you not?”

“yes.”

“no dinner?”

“no.”

“how did you come to neglect that?”

“my father was explaining a recent invention he had perfected, which i was to put on the market.”

“i suppose the possibility of suicide or his death in any way had not occurred to you?”

“no, not at all. we were making elaborate plans for the future.”

possibly it was some prejudice against the man’s appearance which made hatch so dissatisfied with the result of the interview. he felt that he had gained nothing, yet stockton had been absolutely frank, as it seemed. there was one last question.

“have you any recollection of a large family bible in your father’s house?” he asked.

“i have seen it several times,” stockton said.

“is it still there?”

“so far as i know, yes.”

that was the end of the interview, and hatch went straight to the house in dorchester to see miss devan. there, in accordance with instructions from the thinking machine, he asked for the family bible.

“there was one here the other day,” said miss devan, “but it has disappeared.”

“since your father’s death?” asked hatch.

“yes, the next day.”

“have you any idea who took it?”

“not unless — unless —”

“john stockton! why did he take it?” blurted hatch.

there was a little resigned movement of the girl’s hands, a movement which said, “i don’t know.”

“he told me, too,” said hatch indignantly, “that he thought the bible was still here.”

the girl drew close to the reporter and laid one white hand on his sleeve. she looked up into his eyes and tears stood in her own. her lips trembled.

“john stockton has that book,” she said. “he took it away from here the day after my father died, and he did it for a purpose. what, i don’t know.”

“are you absolutely positive he has it?” asked hatch

“i saw it in his room, where he had hidden it,” replied the girl.

3

hatch laid the results of the interviews before the scientist at the beacon hill home. the thinking machine listened without comment up to that point where miss devan had said she knew the family bible to be in the son’s possession.

“if miss devan and stockton do not get along well together, why should she visit stockton’s place at all?” demanded the thinking machine.

“i don’t know,” hatch replied, “except that she thinks he must have had some connection with her father’s death, and is investigating on her own account. what has this bible to do with it anyway?”

“it may have a great deal to do with it,” said the thinking machine enigmatically. “now, the thing to do is to find out if the girl told the truth and if the bible is in stockton’s apartment. now, mr. hatch, i leave that to you. i would like to see that bible. if you can bring it to me, well and good. if you can’t bring it, look at and study the seventh page for any pencil marks in the text, anything whatever. it might be even advisable, if you have the opportunity, to tear out that page and bring it to me. no harm will be done, and it can be returned in proper time.”

perplexed wrinkles were gathering on hatch’s forehead as he listened. what had page 7 of a bible to do with what seemed to be a murder mystery? who had said anything about a bible, anyway? the letter left by stockton mentioned a bible, but that didn’t seem to mean anything. then hatch remembered that same letter carried a figure seven in parentheses which had apparently nothing to do and no connection with any other part of the letter. hatch’s introspective study of the affair was interrupted by the thinking machine.

“i shall await your report here, mr. hatch. if it is what i expect, we shall go out late tonight on a little voyage of discovery. meanwhile see that bible and tell me what you find.”

hatch found the apartments of john stockton on beacon street without any difficulty. in a manner best known to himself he entered and searched the place. when he came out there was a look of chagrin on his face as he hurried to the house of the thinking machine nearby.

“well?” asked the scientist.

“i saw the bible,” said hatch.

“and page 7?”

“was torn out, missing, gone,” replied the reporter.

“ah,” exclaimed the scientist. “i thought so. tonight we will make the little trip i spoke of. by the way, did you happen to notice if john stockton had or used a fountain pen?”

“i didn’t see one,” said hatch.

“well, please see for me if any of his employees have ever noticed one. then meet me here tonight at 10 o’clock.”

thus hatch was dismissed. a little later he called casually on stockton again. there, by inquiries, he established to his own satisfaction that stockton did not own a fountain pen. then with stockton himself he took up the matter of the bible again.

“i understand you to say, mr. stockton,” he began in his smoothest tone, “that you knew of the existence of a family bible, but you did not know if it was still at the dorchester place.”

“that’s correct,” said stockton.

“how is it then,” hatch resumed, “that that identical bible is now at your apartments, carefully hidden in a box under a sofa?”

mr. stockton seemed to be amazed. he arose suddenly and leaned over toward the reporter with hands clenched. there was a glitter of what might have been anger in his eyes.

“what do you know about this? what are you talking about?” he demanded.

“i mean that you had said you did not know where this book was, and meanwhile have it hidden. why?”

“have you seen the bible in my rooms?” asked stockton.

“i have,” said the reporter coolly.

now a new determination came into the face of the merchant. the oiliness of his manner was gone, the sanctimonious smirk had been obliterated, the thin lips closed into a straight, rigid line.

“i shall have nothing further to say,” he declared almost fiercely.

“will you tell me why you tore out the seventh page of the bible?” asked hatch.

stockton stared at him dully, as if dazed for a moment. all the color left his face. there came a startling pallor instead. when next he spoke, his voice was tense and strained.

“is — is — the seventh page missing?”

“yes,” hatch replied. “where is it?”

“i’ll have nothing further to say under any circumstances. that’s all.”

with not the slightest idea of what it might mean or what bearing it had on the matter, hatch had brought out statements which were wholly at variance with facts. why was stockton so affected by the statement that page seven was gone? why had the bible been taken from the dorchester home? why had it been so carefully hidden? how did miss devan know it was there?

these were only a few of the questions that were racing through the reporter’s mind. he did not seem to be able to grasp anything tangible. if there were a cipher hidden in the letter, what was it? what bearing did it have on the case?

seeking a possible answer to some of these questions, hatch took a cab and was soon back at the dorchester house. he was somewhat surprised to see the thinking machine standing on the stoop waiting to be admitted. the scientist took his presence as a matter of course.

“what did you find out about stockton’s fountain pen?” he asked.

“i satisfied myself that he had not owned a fountain pen, at least recently enough for the pen to have been used in writing that letter. i presume that’s what inquiries in that direction mean.”

the two men were admitted to the house and after a few minutes miss devan entered. she understood when the thinking machine explained that they merely wished to see the shop in which mr. stockton had been found dead.

“and also if you have a sample of mr. stockton’s handwriting,” asked the scientist.

“it’s rather peculiar,” miss devan explained, “but i doubt if there is an authentic sample in existence large enough, that is, to be compared with that letter. he had a certain amount of correspondence, but this i did for him on the typewriter. occasionally he would prepare an article for a scientific paper, but these were also dictated to me. he has been in the habit of doing so for years.”

“this letter seems to be all there is?”

“of course his signature appears to checks and in other places. i can produce some of those for you. i don’t think, however, that there is the slightest doubt that he wrote this letter. it is his handwriting.”

“i suppose he never used a fountain pen?” asked the thinking machine.

“not that i know of,” the girl replied. “i have one,” and she took it out of a little gold fascinator she wore at her bosom.

the scientist pressed the point of the pen against his thumb nail, and a tiny drop of blue ink appeared. the letter was written in black. the thinking machine seemed satisfied.

“and now the shop,” he suggested.

miss devan led the way through the long wide hall to the back of the building. there she opened a door, which showed signs of having been battered in, and admitted them. then, at the request of the thinking machine, she rehearsed the story in full, showed him where stockton had been found, where the prussic acid had been broken, and how the servant, montgomery, had broken in the door at her request.

“did you ever find the key to the door?”

“no. i can’t imagine what became of it.”

“is this room precisely as it was when the body was found? that is, has anything been removed from it?”

“nothing,” replied the girl.

“have the servants taken anything out? did they have access to this room?”

“they have not been permitted to enter it at all. the body was removed and the fragments of the acid bottle were taken away, but nothing else.”

“have you ever known of pen and ink being in this room?”

“i hadn’t thought of it.”

“you haven’t taken them out since the body was found, have you?”

“i— i— er — have not,” the girl stammered.

miss devan left the room, and for an hour hatch and the thinking machine conducted the search.

“find a pen and ink,” the thinking machine instructed.

they were not found.

at midnight, which was six hours later, the thinking machine and hutchinson hatch were groping through the cellar of the dorchester house by the light of a small electric lamp which shot a straight beam aggressively through the murky, damp air. finally the ray fell on a tiny door set in the solid wall of the cellar.

there was a slight exclamation from the thinking machine, and this was followed immediately by the sharp, unmistakable click of a revolver somewhere behind them in the dark.

“down, quick,” gasped hatch, and with a sudden blow he dashed aside the electric light, extinguishing it. simultaneously with this there came a revolver shot, and a bullet was buried in the wall behind hatch’s head.

4

the reverberation of the pistol shot was still ringing in hatch’s ears when he felt the hand of the thinking machine on his arm, and then through the utter blackness of the cellar came the irritable voice of the scientist:

“to your right, to your right,” it said sharply.

then, contrary to this advice hatch felt the scientist drawing him to the left. in another moment there came a second shot, and by the flash hatch could see that it was aimed at a point a dozen feet to the right of the point where they had been when the first shot was fired. the person with the revolver had heard the scientist and had been duped.

firmly the scientist drew hatch on until they were almost to the cellar steps. there, outlined against a dim light which came down the stairs, they could see a tall figure peering through the darkness toward a spot opposite where they stood. hatch saw only one thing to do and did it. he leaped forward and landed on the back of the figure, bearing the man to the ground. an instant later his hand closed on the revolver and he wrested it away.

“all right,” he sang out. “i’ve got it.”

the electric light which he had dashed from the hand of the thinking machine gleamed again through the cellar and fell upon the face of john stockton, helpless and gasping in the hands of the reporter.

“well?” asked stockton calmly. “are you burglars or what?”

“let’s go upstairs to the light,” suggested the thinking machine.

it was under these peculiar circumstances that the scientist came face to face for the first time with john stockton. hatch introduced the two men in a most matter-of-fact tone and restored to stockton the revolver. this was suggested by a nod of the scientist’s head. stockton laid the revolver on a table.

“why did you try to kill us?” asked the thinking machine.

“i presumed you were burglars,” was the reply. “i heard the noise down stairs and came down to investigate.”

“i thought you lived on beacon street,” said the scientist.

“i do, but i came here tonight on a little business, which is all my own, and happened to hear you. what were you doing in the cellar?”

“how long have you been here?”

“five or ten minutes.”

“have you a key to this house?”

“i have had one for many years. what is all this, anyway? how did you get in this house? what right had you here?”

“is miss devan in the house tonight?” asked the thinking machine, entirely disregarding the other’s questions.

“i don’t know. i suppose so.”

“you haven’t seen her, of course?”

“certainly not.”

“and you came here secretly without her knowledge?”

stockton shrugged his shoulders and was silent. the thinking machine raised himself on the chair on which he had been sitting and squinted steadily into stockton’s eyes. when he spoke it was to hatch, but his gaze did not waver.

“arouse the servants, find where miss devan’s room is, and see if anything has happened to her,” he directed.

“i think that will be unwise,” broke in stockton quickly.

“why?”

“if i may put it on personal grounds,” said stockton, “i would ask as a favor that you do not make known my visit here, or your own for that matter, to miss devan.”

there was a certain uneasiness in the man’s attitude, a certain eagerness to keep things away from miss devan that spurred hatch to instant action. he went out of the room hurriedly and ten minutes later miss devan, who had dressed quickly, came into the room with him. the servants stood outside in the hall, all curiosity. the closed door barred them from knowledge of what was happening.

there was a little dramatic pause as miss devan entered and stockton arose from his seat. the thinking machine glanced from one to the other. he noted the pallor of the girl’s face and the frank embarrassment of stockton.

“what is it?” asked miss devan, and her voice trembled a little. “why are you all here? what has happened?”

“mr. stockton came here tonight,” the thinking machine began quietly, “to remove the contents from the locked vault in the cellar. he came without your knowledge and found us ahead of him. mr. hatch and myself are here in the course of our inquiry into the matter which you placed in my hands. we also came without your knowledge. i considered this best. mr. stockton was very anxious that his visit should be kept from you. have you anything to say now?”

the girl turned on stockton with magnificent scorn. accusation was in her very attitude. her small hand was pointed directly at stockton and into his face there came a strange emotion, which he struggled to repress.

“murderer! thief!” the girl almost hissed.

“do you know why he came?” asked the thinking machine.

“he came to rob the vault, as you said,” said the girl, fiercely. “it was because my father would not give him the secret of his last invention that this man killed him. how he compelled him to write that letter i don’t know.”

“elizabeth, for god’s sake what are you saying?” asked stockton with ashen face.

“his greed is so great that he wanted all of my father’s estate,” the girl went on impetuously. “he was not content that i should get even a small part of it.”

“elizabeth, elizabeth!” said stockton, as he leaned forward with his head in his hands.

“what do you know about this secret vault?” asked the scientist.

“i— i— have always thought there was a secret vault in the cellar,” the girl explained. “i may say i know there was one because those things my father took the greatest care of were always disposed of by him somewhere in the house. i can imagine no other place than the cellar.”

there was a long pause. the girl stood rigid, staring down at the bowed figure of stockton with not a gleam of pity in her face. hatch caught the expression and it occurred to him for the first time that miss devan was vindictive. he was more convinced than ever that there had been some long standing feud between these two. the thinking machine broke the long silence.

“do you happen to know, miss devan, that page seven of the bible which you found hidden in mr. stockton’s place is missing?”

“i didn’t notice,” said the girl.

stockton had arisen with the words and now stood with white face and listening intently.

“did you ever happen to see a page seven in that bible?” the scientist asked.

“i don’t recall.”

“what were you doing in my rooms?” demanded stockton of the girl.

“why did you tear out page seven?” asked the thinking machine.

stockton thought the question was addressed to him and turned to answer. then he saw it was unmistakably a question to miss devan and turned again to her.

“i didn’t tear it out,” exclaimed miss devan. “i never saw it. i don’t know what you mean.”

the thinking machine made an impatient gesture with his hands; his next question was to stockton.

“have you a sample of your father’s handwriting?’”

“several,” said stockton. “here are three or four letters from him.”

miss devan gasped a little as if startled and stockton produced the letters and handed them to the thinking machine. the latter glanced over two of them.

“i thought, miss devan, you said your father always dictated his letters to you?”

“i did say so,” said the girl. “i didn’t know of the existence of these.”

“may i have these?” asked the thinking machine.

“yes. they are of no consequence.”

“now let’s see what is in the secret vault,” the scientist went on.

he arose and led the way again into the cellar, lighting his path with the electric bulb. stockton followed immediately behind, then came miss devan, her white dressing gown trailing mystically in the dim light, and last came hatch. the thinking machine went straight to that spot where he and hatch had been when stockton had fired at them. again the rays of the light revealed the tiny door set into the wall of the cellar. the door opened readily at his touch; the small vault was empty.

intent on his examination of this, the thinking machine was oblivious for a moment to what was happening. suddenly there came again a pistol shot, followed instantly by a woman’s scream.

“my god, he’s killed himself. he’s killed himself.”

it was miss devan’s voice.

5

when the thinking machine flashed his light back into the gloom of the cellar, he saw miss devan and hatch leaning over the prostrate figure of john stockton. the latter’s face was perfectly white save just at the edge of the hair, where there was a trickle of red. in his right hand he clasped a revolver.

“dear me! dear me!” exclaimed the scientist. “what is it?’”

“stockton shot himself,” said hatch, and there was excitement in his tone.

on his knees the scientist made a hurried examination of the wounded man, then suddenly — it may have been inadvertently — he flashed the light in the face of miss devan.

“where were you?” he demanded quickly.

“just behind him,” said the girl. “will he die? is it fatal?”

“hopeless,” said the scientist. “let’s get him upstairs.”

the unconscious man was lifted and with hatch leading was again taken to the room which they had left only a few minutes before. hatch stood by helplessly while the thinking machine, in his capacity of physician, made a more minute examination of the wound. the bullet mark just above the right temple was almost bloodless; around it there were the unmistakeable marks of burned powder.

“help me just a moment, miss devan,” requested the thinking machine, as he bound an improvised handkerchief bandage about the head. miss devan tied the final knots of the bandage and the thinking machine studied her hands closely as she did so. when the work was completed he turned to her in a most matter of fact way.

“why did you shoot him?” he asked.

“i— i—” stammered the girl, “i didn’t shoot him, he shot himself.”

“how come those powder marks on your right hand?”

miss devan glanced down at her right hand, and the color which had been in her face faded as if by magic. there was fear, now, in her manner.

“i— i don’t know,” she stammered. “surely you don’t think that i—”

“mr. hatch, ‘phone at once for an ambulance and then see if it is possible to get detective mallory here immediately. i shall give miss devan into custody on the charge of shooting this man.”

the girl stared at him dully for a moment and then dropped back into a chair with dead white face and fear-distended eyes. hatch went out, seeking a telephone, and for a time miss devan sat silent, as if dazed. finally, with an effort, she aroused herself and facing the thinking machine defiantly, burst out:

“i didn’t shoot him. i didn’t, i didn’t. he did it himself.”

the long, slender fingers of the thinking machine closed on the revolver and gently removed it from the hand of the wounded man.

“ah, i was mistaken,” he said suddenly, “he was not as badly wounded as i thought. see! he is reviving.”

“reviving,” exclaimed miss devan. “won’t he die, then?’”

“why?” asked the thinking machine sharply.

“it seems so pitiful, almost a confession of guilt,” she hurriedly exclaimed. “won’t he die?”

gradually the color was coming back into stockton’s face. the thinking machine bending over him, with one hand on the heart, saw the eyelids quiver and then slowly the eyes opened. almost immediately the strength of the heart beat grew perceptibly stronger. stockton stared at him a moment, then wearily his eyelids drooped again.

“why did miss devan shoot you?” the thinking machine demanded.

there was a pause and the eyes opened for the second time. miss devan stood within range of the glance, her hands outstretched entreatingly toward stockton.

“why did she shoot you?” repeated the thinking machine.

“she — did — not,” said stockton slowly. “i— did — it — myself.”

for an instant there was a little wrinkle of perplexity on the brow of the thinking machine and then it passed.

“purposely?” he asked.

“i did it myself.”

again the eyes closed and stockton seemed to be passing into unconsciousness. the thinking machine glanced up to find an infinite expression of relief on miss devan’s face. his own manner changed; became almost abject, in fact, as he turned to her again.

“i beg your pardon,” he said. “i made a mistake.”

“will he die?”

“no, that was another mistake. he will recover.”

within a few moments a city hospital ambulance rattled up to the door and john stockton was removed. it was with a feeling of pity that hatch assisted miss devan, now almost in a fainting condition, to her room. the thinking machine had previously given her a slight stimulant. detective mallory had not answered the call by ‘phone.

the thinking machine and hatch returned to boston. at the park street subway they separated, after the thinking machine had given certain instructions. hatch spent most of the following day carrying out these instructions. first he went to see dr. benton, the physician who issued the death certificate on which pomeroy stockton was buried. dr. benton was considerably alarmed when the reporter broached the subject of his visit. after a time he talked freely of the case.

“i have known john stockton since we were in college together,” he said, “and i believe him to be one of the few really good men i know. i can’t believe otherwise. singularly enough, he is also one of the few good men who has made his own fortune. there is nothing hypocritical about him.

“immediately after his father was found dead, he ‘phoned to me and i went out to the house in dorchester. he explained then that it was apparent pomeroy stockton had committed suicide. he dreaded the disgrace that public knowledge would bring on an honored name, and asked me what could be done. i suggested the only thing i knew — that was the issuance of a death certificate specifying natural causes — heart disease, i said. this act was due entirely to my friendship for him.

“i examined the body and found a trace of prussic acid on pomeroy’s tongue. beside the chair on which he sat a bottle of prussic acid had been broken. i made no autopsy, of course. ethically i may have sinned, but i feel that no real harm has been done. of course, now that you know the real facts my entire career is at stake.”

“there is no question in your mind but what it was suicide?” asked hatch.

“not the slightest. then, too, there was the letter, which was found in pomeroy stockton’s pocket. i saw that and if there had been any doubt then it was removed. this letter, i think, was then in miss devan’s possession. i presume it is still.”

“do you know anything about miss devan?”

“nothing, except that she is an adopted daughter, who for some reason retained her own family name. three or four years ago she had a little love affair, to which john stockton objected. i believe he was the cause of it being broken off. as a matter of fact, i think at one time he was himself in love with her and she refused to accept him as a suitor. since that time there has been some slight friction, but i know nothing of this except in a general way from what he has said to me.”

then hatch proceeded to carry out the other part of the thinking machine’s instructions. this was to see the attorney in whose possession pomeroy stockton’s will was supposed to be and to ask him why there had been a delay in the reading of the will.

hatch found the attorney, frederick sloane, without difficulty. without reservation hatch laid all the circumstances as he knew them before mr. sloane. then came the question of why the will had not been read. mr. sloane, too, was frank.

“it’s because the will is not now in my possession,” he said. “it has either been mislaid, lost, or possibly stolen. i did not care for the family to know this just now, and delayed the reading of the will while i made a search for it. thus far i have found not a trace. i haven’t even the remotest idea where it is.”

“what does the will provide?” asked hatch.

“it leaves the bulk of the estate to john stockton, settles an annuity of $5,000 a year on miss devan, gives her the dorchester house, and specifically cuts off other relatives whom pomeroy stockton once accused of stealing an invention he made. the letter, found after mr. stockton’s death —”

“you knew of that letter, too?” hatch interrupted.

“oh, yes, this letter confirms the will, except, in general terms, it also cuts off miss devan.”

“would it not be to the interest of the other immediate relatives of stockton, those who were specifically cut off, to get possession of that will and destroy it?”

“of course it might be, but there has been no communication between the two branches of the family for several years. that branch lives in the far west and i have taken particular pains to ascertain that they could not have had anything to do with the disappearance of the will.”

with these new facts in his possession, hatch started to report to the thinking machine. he had to wait half an hour or so. at last the scientist came in.

“i’ve been attending an autopsy,” he said.

“an autopsy? whose?”

“on the body of pomeroy stockton.”

“why, i had thought he had been buried.”

“no, only placed in a receiving vault. i had to call the attention of the medical examiner to the case in order to get permission to make an autopsy. we did it together.”

“what did you find?” asked hatch.

“what did you find?” asked the thinking machine, in turn.

briefly hatch told him of the interview with dr. benton and mr. sloane. the scientist listened without comment and at the end sat back in his big chair squinting at the ceiling.

“that seems to finish it,” he said. “these are the questions which were presented: first, in what manner did pomeroy stockton die? second, if not suicide, as appeared, what motive was there for anything else? third, if there was a motive, to whom does it lead? fourth, what was in the cipher letter? now, mr. hatch, i think i may make all of it clear. there was a cipher in the letter — what may be described as a cipher in five, the figure five being the key to it.”

6

“first, mr. hatch,” the thinking machine resumed, as he drew out and spread on a table the letter which had been originally placed in his hands by miss devan, “the question of whether there was a cipher in this letter was to be definitely decided.

“there are a thousand different kinds of ciphers. one of them, which we will call the arbitrary cipher, is excellently illustrated in poe’s story, ‘the gold bug’. in that cipher, a figure or symbol is made to represent each letter of the alphabet.

“then, there are book ciphers, which are, perhaps, the safest of all ciphers, because without a clue to the book from which words may be chosen and designated by numbers, no one can solve it.

“it would be useless for me to go into this matter at any length, so let us consider this particular letter as a cipher possibility. a careful study of the letter develops three possible starting points. the first of these is the general tone of the letter. it is not a direct, straight-away statement such as a man about to commit suicide would write unless he had a purpose — that is, a purpose beyond the mere apparent meaning of the letter itself. therefore we will suppose there was another purpose hidden behind a cipher.

“the second starting point is that offered by the absence of one word. you will see that the word ‘in’ should appear between the word ‘cherished’ and ‘secret’. this, of course, may have been an oversight in writing, the sort of thing anyone might do. but further down we find the third starting point.

“this is the figure seven in parentheses. it apparently has no connection whatever with what precedes or follows. it could not have been an accident. therefore what did it mean? was it a crude outward indication of a hurriedly constructed cipher?

“i took the figure seven at first to be a sort of key to the entire letter, always presuming there was a cipher. i counted seven words down from that figure and found the word ‘binding’. seven words from that down made the next word ‘give’. together the two words seemed to mean something.

“i stopped there and started back. the seventh word up is ‘and’. the seventh word from ‘and’, still counting backward, seemed meaningless. i pursued that theory of seven all the way through the letter and found only a jumble of words. it was the same way counting seven letters. these letters meant nothing unless each letter was arbitrarily taken to represent another letter. this immediately led to intricacies. i believe always in exhausting simple possibilities first, so i started over again.

“now what word nearest to the seven meant anything when taken together with it? not ‘family’, not ‘bible’, not ‘son’, as the vital words appear from the seven down. going up from the seven, i did find a word which applied to it and meant something. that was the word ‘page’. i had immediately ‘page seven’. ‘page’ was the fifth word up from the seven.

“what was the next fifth word, still going up? this was ‘on’. then i had ‘on page seven’— connected words appearing in order, each being the fifth from the other. the fifth word down from seven i found was ‘family’; the next fifth word was ‘bible’; thus, ‘on page seven family bible’.

“it is unnecessary to go further into the study i made of the cipher. i worked upward from the seven, taking each fifth word until i had all the cipher words. i have underscored them here. read the words underscored and you have the cipher.”

hatch took the letter marked as follows:

to those concerned:

tired of it all i seek the end, and am content. ambition is dead; the grave yawns greedily at my feet, and with the labor of my own hands lost i greet death of my own will, by my own act. to my son i leave all, and you who maligned me, you who discouraged me, you may read this and know i punish you thus. it’s for him, my son, to forgive. i dared in life and dare dead your everlasting anger, not alone that you didn’t speak, but that you cherished secret, and my ears are locked forever against you. my vault is my resting place. on the brightest and dearest page of life i wrote (7) my love for him. family ties, binding as the bible itself, bade me give all to my son.

good-bye. i die.

pomeroy stockton

slowly hatch read this:

“i am dead at the hands of my son. you who read punish him. i dare not speak. secret locked vault on page 7 family bible.”

“well, by george!” exclaimed the reporter. it was a tribute to the thinking machine, as well as an expression of amazement at what he read.

“you see,” explained the thinking machine, “if the word ‘in’ had appeared between ‘cherished’ and ‘secret’, as it would naturally have done, it would have lost the order of the cipher, therefore it was purposely left out.”

“it’s enough to send stockton to the electric chair,” said hatch.

“it would be if it were not a forgery,” said the scientist testily.

“a forgery,” gasped hatch. “didn’t pomeroy stockton write it?”

“no.”

“surely not john stockton?”

“no.”

“well, who then?”

“miss devan.”

“miss devan!” hatch repeated in amazement. “then, miss devan killed pomeroy stockton?”

“no, he died a natural death.”

hatch’s head was whirling. a thousand questions demanded an immediate answer. he stared mouth agape at the thinking machine. all his ideas of the case were tumbling about him. nothing remained.

“briefly, here is what happened,” said the thinking machine. “pomeroy stockton died a natural death of heart disease. miss devan found him dead, wrote this letter, put it in his pocket, put a drop of prussic acid on his tongue, smashed the bottle of acid, left the room, locked the door, and next day had it broken down.

“it was she who shot john stockton. it was she who tore out page seven of that family bible, and then hid the book in stockton’s room. it was she who in some way got hold of the will. she either has it or destroyed it. it was she who took advantage of her aged benefactor’s sudden death to further as weird and inhuman a plot against another as a woman can devise. there is nothing on god’s earth as bad as a bad woman, and nothing as good as a good one. i think that has been said before.”

“but as to this case,” hatch interrupted. “how? what? why?”

“i read the cipher within a few hours after i got the letter,” replied the thinking machine. “naturally i wanted to find out then who and what this son was.

“i had miss devan’s story, of course — a story of disagreement between father and son, quarreling and all that. it was also a story which showed a certain underlying animosity despite miss devan’s cleverness. she had so mingled fact with fiction that it was not altogether easy to weed out the truth, therefore i believed what i chose.

“miss devan’s idea, as expressed to me, was that the letter was written under coercion. men who are being murdered don’t write cipher letters as intricate as that; and men who are committing suicide have no obvious reasons for writing such letters. the line ‘i dare not speak’ was silly. pomeroy stockton was not a prisoner. if he had feared a conspiracy to kill him why shouldn’t he speak?

“all these things were in my mind when i asked you to see stockton. i was particularly anxious to hear what he had to say as to the family bible. and yet i may say i knew that page seven had been torn out of the book and was then in miss devan’s possession.

“i may say, too, that i knew that the secret vault was empty. whatever these two things contained, supposing she wrote the cipher, had been removed or she would not have called attention to them in this cipher. i had an idea that she might have written it from the mere fact that it was she who first called my attention to the possibility of a cipher.

“assuming then that the cipher was a forgery, that she wrote it, that it directly accused john stockton, that she brought it to me, i had fairly conclusive proof that if pomery stockton had been murdered she had had a hand in it. john stockton’s motive in trying to suppress the fact of a suicide, as he thought it, was perfectly clear. it was, as he said, to avoid disgrace. such things are done frequently.

“from the moment you told him of the possibility of murder, he suspected miss devan. why? because, above all, she had the opportunity, because she wanted the bulk of the estate, because there was some animosity against john stockton.

“this now proves to have been a broken-off love affair. john stockton broke it off. he himself had loved miss devan. she had refused him. later, when he broke off the love affair, she hated him.

“her plan for revenge was almost diabolical. it was intended to give her full revenge and the estate at the same time. she hoped, she knew, that i would read that cipher. she planned that it would send john stockton to the electric chair.”

“horrible!” commented hatch with a little shudder.

“it was a fear that this plan might go wrong that induced her to try to kill stockton by shooting him. the cellar was dark, but she forgot that ninety-nine revolvers out of a hundred leave slight powder stains on the hand of the person who fires them. stockton said that she did not shoot him, because of that inexplicable loyalty which some men show to a woman they love or have loved.

“stockton made his secret visit to the house that night to get what was in that vault without her knowledge. he knew of its existence. his father had probably told him. the thing that appeared on page seven of the family bible was in all probability the copper hardening process he was perfecting. i should think it had been written there in invisible ink. john stockton knew this was there. his father told him. if his father told it, miss devan probably overheard it. she knew it, too.

“now the actual circumstances of the death. the girl must have had and used a key to the work room. after john stockton left the house that monday night she entered that room. she found his father dead of heart disease. the autopsy proved this.

“then the whole scheme was clear to her. she forged that cipher letter — as pomeroy stockton’s secretary she probably knew the handwriting better than anyone else in the world — placed it in his pocket, and the rest of it you know.”

“but the bible in john stockton’s room?” asked hatch.

“was placed there by miss devan,” replied the thinking machine. “it was a part of the general scheme to hopelessly implicate stockton. she is a clever woman. she showed that when she produced the fountain pen, having carefully filled it with blue instead of black ink.”

“what was in the locked vault?”

“that i can only conjecture. it is not impossible that the inventor had only part of the formula he so closely guarded written on the bible leaf and the other part of it in that vault, together with other valuable documents.

“i may add that the letters which john stockton had were not forged. they were written without miss devan’s knowledge. there was a vast difference in the handwriting of the cipher letter which she wrote and those others which the father wrote.

“of course it is obvious that the missing will is now, or was, in miss devan’s possession. how she got it, i don’t know. with that out of the way and this cipher unravelled apparently proving the son’s guilt, at least half, possibly all, of the estate would have gone to her.”

hatch lighted a cigarette thoughtfully and was silent for a moment.

“what will be the end of it all?” he asked. “of course, i understand that john stockton will recover.”

“the result will be that the world will lose a great scientific achievement — the secret of hardening copper, which pomeroy stockton had rediscovered. i think it safe to say that miss devan has burned every scrap of this.”

“but what will become of her?”

“she knows nothing of this. i believe she will disappear before stockton recovers. he wouldn’t prosecute anyway. remember he loved her once.”

john stockton was convalescent two weeks later, when a nurse in the city hospital placed an envelope in his hands. he opened it and a little cloud of ashes filtered through his fingers onto the bed clothing. he sank back on his pillow, weeping.