The Treasure-Train

by Arthur B. Reeve

  VIII

  THE VITAL PRINCIPLE

  "That's the handwriting of a woman--a jealous woman," remarked Kennedy,handing to me a dainty note on plain paper which had come in themorning mail.

  I did not stop to study the writing, for the contents of the letter were more fascinating than even Kennedy's new science of graphology.

  You don't know me [the note read], but I know of your work of scientific investigation.

  Let me inform you of something that ought to interest you.

  In the Forum Apartments you will find that there is some strange disease affecting the Wardlaw family. It is a queer disease of the nerves. One is dead. Others are dying.

  Look into it.

  A FRIEND.

  As I read it I asked myself vainly what it could mean. There was nodirect accusation against any one, yet the implication was plain. Awoman had been moved by one of the primal passions to betray--some one.

  I looked up from the note on the table at Craig. He was still studyingthe handwriting.

  "It's that peculiar vertical, angular hand affected by many women," hecommented, half to himself. "Even at a glance you can see that it'swritten hastily, as if under the stress of excitement and suddenresolution. You'll notice how those capitals--" The laboratory dooropened, interrupting him.

  "Hello, Kennedy," greeted Doctor Leslie, our friend, the coroner'sphysician, who had recently been appointed Health Commissioner of thecity.

  It was the first time we had seen him since the appointment and wehastened to congratulate him. He thanked us absently, and it wasevident that there was something on his mind, some problem which, inhis new office, he felt that he must solve if for no other purpose thanto justify his reputation. Craig said nothing, preferring to let thecommissioner come to the point in his own way.

  "Do you know, Kennedy," he said, at length, turning in his chair andfacing us, "I believe we have found one of the strangest cases in thehistory of the department."

  The commissioner paused, then went on, quickly, "It looks as if it werenothing less than an epidemic of beriberi--not on a ship coming intoport as so often happens, but actually in the heart of the city."

  "Beriberi--in New York?" queried Craig, incredulously.

  "It looks like it," reiterated Leslie, "in the family of a DoctorWardlaw, up-town here, in the Forum--"

  Kennedy had already shoved over the letter he had just received. Lesliedid not finish the sentence, but read the note in amazement.

  "What are the symptoms?" inquired Craig.

  "What makes you think it is beriberi, of all things?"

  "Because they show the symptoms of beriberi," persisted Leslie,doggedly. "You know what they are like. If you care to go into thematter I think I can convince you."

  The commissioner was still holding the letter and gazing, puzzled, fromit to us. It seemed as if he regarded it merely as confirming his ownsuspicions that something was wrong, even though it shed no real lighton the matter.

  "How did you first hear of it?" prompted Kennedy.

  Leslie answered frankly. "It came to the attention of the department asthe result of a reform I have inaugurated. When I went in office Ifound that many of the death certificates were faulty, and in thecourse of our investigations we ran across one that seemed to be mostvaguely worded. I don't know yet whether it was ignorance--or somethingworse. But it started an inquiry. I can't say that I'm thoroughlysatisfied with the amended certificate of the physician who attendedMrs. Marbury, the mother of Doctor Wardlaw's wife, who died about aweek ago--Doctor Aitken."

  "Then Wardlaw didn't attend her himself?" asked Kennedy.

  "Oh no. He couldn't, under the circumstances, as I'll show youpresently, aside from the medical ethics of the case. Aitken was thefamily physician of the Marburys."

  Kennedy glanced at the note. "One is dead. Others are dying," he read."Who are the others? Who else is stricken?"

  "Why," continued Leslie, eager to unburden his story, "Wardlaw himselfhas the marks of a nervous affection as plainly as the eye can see it.You know what it is in this disease, as though the nerves were wastingaway. But he doesn't seem half as badly affected as his wife. They tellme Maude Marbury was quite a beauty once, and photographs I have seenprove it. She's a wreck now. And, of course, the old lady must havebeen the most seriously affected of them all."

  "Who else is there in the household?" inquired Kennedy, growing moreand more interested.

  "Well," answered Leslie, slowly, "they've had a nurse for some time,Natalie Langdale. Apparently she has escaped."

  "Any servants?"

  "Some by the day; only one regularly--a Japanese, Kato. He goes home atnight, too. There's no evidence of the disease having affected him."

  I caught Leslie's eye as he gave the last information. Though I did notknow much about beriberi, I had read of it, and knew that it wasespecially prevalent in the Orient. I did not know what importance toattach to Kato and his going home at night.

  "Have you done any investigating yourself?" asked Kennedy.

  Leslie hesitated a moment, as though deprecating his own efforts inthat line, though when he spoke I could see no reason why he should,except that it had so often happened that Kennedy had seen the obviouswhich was hidden from most of those who consulted him.

  "Yes," he replied, "I thought perhaps there might be some motive backof it all which I might discover. Possibly it was old Mrs. Marbury'sfortune--not a large one, but substantial. So it occurred to me thatthe will might show it. I have been to the surrogate."

  "And?" prompted Kennedy, approvingly.

  "Mrs. Marbury's will has already been offered for probate. It directs,among other things, that twenty-five thousand dollars be given by herdaughter, to whom she leaves the bulk of her fortune, to Doctor Aitken,who had been Mr. Marbury's physician and her own."

  Leslie looked at us significantly, but Kennedy made no comment.

  "Would you like to go up there and see them?" urged the commissioner,anxious to get Craig's final word on whether he would co-operate in theaffair.

  "I certainly should," returned Kennedy, heartily, folding up the letterwhich had first attracted his interest. "It looks as if there were moreto this thing than a mere disease, however unusual."

  Doctor Leslie could not conceal his satisfaction, and without delayinga moment more than was necessary hurried us out into one of thedepartment cars, which he had left waiting outside, and directed thedriver to take us to the Forum Apartments, one of the newest and mostfashionable on the Drive.

  Miss Langdale met us at the door and admitted us into the apartment.She was a striking type of trained nurse, one of those who seembubbling over with health and vivacity. She seemed solicitous of herpatients and reluctant to have them disturbed, yet apparently notdaring to refuse to admit Doctor Leslie. There was nothing in hersolicitude, however, that one could take exception to.

  Miss Langdale conducted us softly down a hallway through the middle ofthe apartment, and I noted quickly how it was laid out. On one side wepassed a handsomely furnished parlor and dining-room, opposite whichwere the kitchen and butler's pantry, and, farther along, a bedroom andthe bath. On down the hall, on the right, was Doctor Wardlaw's study,or rather den, for it was more of a library than an office.

  The nurse led the way, and we entered. Through the windows one caught abeautiful vista of the Drive, the river, and the Jersey shore. I gazedabout curiously. Around the room there were bookcases and cabinets, adesk, some easy-chairs, and in the corner a table on which were some ofWardlaw's paraphernalia, for, although he was not a practisingphysician, he still specialized in his favorite branches of eye and earsurgery.

  Miss Langdale left us a moment, with a hasty excuse that she mustprepare Mrs. Wardlaw for the unexpected visit. The preparation,however, did not take long, for a moment later Maude Wardlaw entered,supported by her nurse.

  Her lips moved mechanically as she saw us, but we could not hear whatshe said. As s
he walked, I could see that she had a peculiar gait, asthough she were always lifting her feet over small obstacles. Her eyes,too, as she looked at us, had a strange squint, and now and then themuscles of her face twitched. She glanced from Leslie to Kennedyinquiringly, as Leslie introduced us, implying that we were from hisoffice, then dropped into the easy-chair. Her breathing seemed to belabored and her heart action feeble, as the nurse propped her upcomfortably.

  As Mrs. Wardlaw's hand rested on the arm of the chair I saw that therewas a peculiar flexion of her wrist which reminded me of the so-called"wrist-drop" of which I had heard. It was almost as if the muscles ofher hands and arms, feet and legs, were weak and wasting. Once she hadbeen beautiful, and even now, although she seemed to be a wreck of herformer self, she had a sort of ethereal beauty that was very touching.

  "Doctor is out--just now," she hesitated, in a tone that hinted at theloss of her voice. She turned appealingly to Miss Langdale. "Oh," shemurmured, "I feel so badly this morning--as if pins and needles weresticking in me--vague pains in all my limbs--"

  Her voice sank to a whisper and only her lips moved feebly. One hadonly to see her to feel sympathy. It seemed almost cruel to intrudeunder the circumstances, yet it was absolutely necessary if Craig wereto accomplish anything. Maude Wardlaw, however, did not seem tocomprehend the significance of our presence, and I wondered how Kennedywould proceed.

  "I should like to see your Japanese servant, Kato," he began, directly,somewhat to my surprise, addressing himself rather to Miss Langdalethan to Mrs. Wardlaw.

  The nurse nodded and left the room without a word, as thoughappreciating the anomalous position in which she was placed astemporary mistress of the household.

  A few moments later Kato entered. He was a typical specimen of thesuave Oriental, and I eyed him keenly, for to me East was East and Westwas West, and I was frankly suspicious, especially as I saw no reasonto be otherwise in Kennedy's manner. I waited eagerly to see what Craigwould do.

  "Sit here," directed Kennedy, indicating a straight-backed chair, onwhich the Japanese obediently sat. "Now cross your knees."

  As Kato complied, Kennedy quickly brought his hand, held flat and palmupward, sharply against the Jap's knee just below the kneecap. Therewas a quick reflex jerk of the leg below the knee in response.

  "Quite natural," Kennedy whispered, turning to Leslie, who nodded.

  He dismissed Kato without further questioning, having had anopportunity to observe whether he showed any of the symptoms that hadappeared in the rest of the family. Craig and the Health Commissionerexchanged a few words under their breath, then Craig crossed the roomto Mrs. Wardlaw. The entrance of Kato had roused her momentarily andshe had been watching what was going on.

  "It is a simple test," explained Kennedy, indicating to Miss Langdalethat he wished to repeat it on her patient.

  Mrs. Wardlaw's knee showed no reflex! As he turned to us, we could seethat Kennedy's face was lined deeply with thought, and he paced up anddown the room once or twice, considering what he had observed.

  I could see that even this simple interview had greatly fatigued Mrs.Wardlaw. Miss Langdale said nothing, but it was plainly evident thatshe objected strongly to the strain on her patient's strength.

  "That will be sufficient," nodded Craig, noticing the nurse. "Thank youvery much. I think you had better let Mrs. Wardlaw rest in her ownroom."

  On the nurse's arm Mrs. Wardlaw withdrew and I looked inquiringly fromKennedy to Doctor Leslie. What was it that had made this beautifulwoman such a wreck? It seemed almost as though the hand of fate hadstretched out against one who had all to make her happy--wealth, youth,a beautiful home--for the sullen purpose of taking away what had beenbestowed so bounteously.

  "It is polyneuritis, all right, Leslie," Craig agreed, the moment wewere alone.

  "I think so," coincided Leslie, with a nod. "It's the CAUSE I can't getat. Is it polyneuritis of beriberi--or something else?" Kennedy did notreply immediately.

  "Then there are other causes?" I inquired of Leslie.

  "Alcohol," he returned, briefly. "I don't think that figures in thisinstance. At least I've seen no evidence."

  "Perhaps some drug?" I hazarded at a venture.

  Leslie shrugged.

  "How about the food?" inquired Craig. "Have you made any attempt toexamine it?"

  "I have," replied the commissioner. "When I came up here first Ithought of that. I took samples of all the food that I could find inthe ice-box, the kitchen, and the butler's pantry. I have the wholething, labeled, and I have already started to test them out. I'll showyou what I have done when we go down to the department laboratory."

  Kennedy had been examining the books in the bookcase and now pulled outa medical dictionary. It opened readily to the heading,"Polyneuritis--multiple neuritis."

  I bent over and read with him. In the disease, it seemed, the nervefibers themselves in the small nerves broke down and the affection wasmotor, sensory, vasomotor, or endemic. All the symptoms describedseemed to fit what I had observed in Mrs. Wardlaw.

  "Invariably," the article went on, "it is the result of some toxicsubstance circulating in the blood. There is a polyneuritis psychosis,known as Korsakoff's syndrome, characterized by disturbances of thememory of recent events and false reminiscences, the patient beingrestless and disorientated."

  I ran my finger down the page until I came to the causes. There werealcohol, lead, arsenic, bisulphide of carbon, diseases such asdiabetes, diphtheria, typhoid, and finally, much to my excitement, wasenumerated beriberi, with the added information, "or, as the Japanesecall it, kakke."

  I placed my finger on the passage and was about to say something aboutmy suspicions of Kato when we heard the sound of footsteps in the hall,and Craig snapped the book shut, returning it hastily to the bookcase.It was Miss Langdale who had made her patient comfortable in bed andnow returned to us.

  "Who is this Kato?" inquired Craig, voicing what was in my own mind."What do you know about him?"

  "Just a young Japanese from the Mission downtown," replied the nurse,directly. "I don't suppose you know, but Mrs. Wardlaw used to begreatly interested in religious and social work among the Japanese andChinese; would be yet, but," she added, significantly, "she is notstrong enough. They employed him before I came here, about a year ago,I think."

  Kennedy nodded, and was about to ask another question, when there was aslight noise out in the hall. Thinking it might be Kato himself, Isprang to the door.

  Instead, I encountered a middle-aged man, who drew back in surprise atseeing me, a stranger.

  "Oh, good morning, Doctor Aitken!" greeted Miss Langdale, in quite thecasual manner of a nurse accustomed to the daily visit at about thishour.

  As for Doctor Aitken, he glanced from Leslie, whom he knew, to Kennedy,whom he did not know, with a very surprised look on his face. In fact,I got the impression that after he had been admitted he had paused amoment in the hall to listen to the strange voices in the Wardlaw study.

  Leslie nodded to him and introduced us, without quite knowing what tosay or do, any more than Doctor Aitken.

  "A most incomprehensible case," ventured Aitken to us. "I can't, forthe life of me, make it out." The doctor showed his perplexity plainly,whether it was feigned or not.

  "I'm afraid she's not quite so well as usual," put in Miss Langdale,speaking to him, but in a manner that indicated that first of all shewished any blame for her patient's condition to attach to us and not toherself.

  Doctor Aitken pursed up his lips, bowed excusingly to us, and turneddown the hall, followed by the nurse. As they passed on to Mrs.Wardlaw's room, I am sure they whispered about us. I was puzzled byDoctor Aitken. He seemed to be sincere, yet, under the circumstances, Ifelt that I must be suspicious of everybody and everything.

  Alone again for a moment, Kennedy turned his attention to the furnitureof the room, and finally paused before a writing-desk in the corner. Hetried it. It was not locked and he opened it. Quickly he ran through apile of papers
carefully laid under a paper-weight at the back.

  A suppressed exclamation from him called my attention to something thathe had discovered. There lay two documents, evidently recently drawnup. As we looked over the first, we saw that it was Doctor Wardlaw'swill, in which he had left everything to his wife, although he was notan especially wealthy man. The other was the will of Mrs. Wardlaw.

  We devoured it hastily. In substance it was identical with the first,except that at the end she had added two clauses. In the first she haddone just as her mother had directed. Twenty-five thousand dollars hadbeen left to Doctor Aitken. I glanced at Kennedy, but he was readingon, taking the second clause. I read also. Fifty thousand dollars wasgiven to endow the New York Japanese Mission.

  Immediately the thought of Kato and what Miss Langdale had just told usflashed through my mind.

  A second time we heard the nurse's footsteps on the hardwood floor ofthe hall. Craig closed the desk softly.

  "Doctor Aitken is ready to go," she announced. "Is there anything moreyou wish to ask?"

  Kennedy spoke a moment with the doctor as he passed out, but, asidefrom the information that Mrs. Wardlaw was, in his opinion, growingworse, the conversation added nothing to our meager store ofinformation.

  "I suppose you attended Mrs. Marbury?" ventured Kennedy of MissLangdale, after the doctor had gone.

  "Not all the time," she admitted. "Before I came there was anothernurse, a Miss Hackstaff."

  "What was the matter? Wasn't she competent?"

  Miss Langdale avoided the question, as though it were a breach ofprofessional etiquette to cast reflections on another nurse, althoughwhether that was the real reason for her reticence did not appear.Craig seemed to make a mental note of the fact.

  "Have you seen anything--er--suspicious about this Kato?" put inLeslie, while Kennedy frowned at the interruption.

  Miss Langdale answered quickly, "Nothing."

  "Doctor Aitken has never expressed any suspicion?" pursued Leslie.

  "Oh no," she returned. "I think I would have known it if he had any.No, I've never heard him even hint at anything." It was evident thatshe wished us to know that she was in the confidence of the doctor.

  "I think we'd better be going," interrupted Kennedy, hastily, notapparently pleased to have Leslie break in in the investigation just atpresent.

  Miss Langdale accompanied us to the door, but before we reached it itwas opened from the outside by a man who had once been and yet washandsome, although one could see that he had a certain appearance ofhaving neglected himself.

  Leslie nodded and introduced us. It was Doctor Wardlaw.

  As I studied his face I could see that, as Leslie had already told us,it plainly bore the stigma of nervousness.

  "Has Doctor Aitken been here?" he inquired, quickly, of the nurse.Then, scarcely waiting for her even to nod, he added: "What did he say?Is Mrs. Wardlaw any better?"

  Miss Langdale seemed to be endeavoring to make as optimistic a reportas the truth permitted, but I fancied Wardlaw read between the lines.As they talked it was evident that there was a sort of restraintbetween them. I wondered whether Wardlaw might not have some lurkingsuspicion against Aitken, or some one else. If he had, even in hisnervousness he did not betray it.

  "I can't tell you how worried I am," he murmured, almost to himself."What can this thing be?"

  He turned to us, and, although he had just been introduced, I am surethat our presence seemed to surprise him, for he went on talking tohimself, "Oh yes--let me see--oh yes, friends of Doctor--er--Leslie."

  I had been studying him and trying to recall what I had just read ofberiberi and polyneuritis. There flashed over my mind the recollectionof what had been called Korsakoff's syndrome, in which one of themental disturbances was the memory of recent events. Did not this, Iasked myself, indicate plainly enough that Leslie might be right in hissuspicions of beriberi? It was all the more apparent a moment laterwhen, turning to Miss Langdale, Wardlaw seemed almost instantly toforget our presence again. At any rate, his anxiety was easy to see.

  After a few minutes' chat during which Craig observed Wardlaw'ssymptoms, too, we excused ourselves, and the Health Commissionerundertook to conduct us to his office to show us what he had done sofar. As for me, I could not get Miss Langdale out of my mind, andespecially the mysterious letter to Kennedy. What of it and what of itssecret sender?

  None of us said much until, half an hour later, in the departmentlaboratory, Leslie began to recapitulate what he had already done inthe case.

  "You asked whether I had examined the food," he remarked, pausing in acorner before several cages in which were a number of pigeons,separated and carefully tagged. With a wave of his hand at one group ofcages he continued: "These fellows I have been feeding exclusively onsamples of the various foods which I took from the Wardlaw family whenI first went up there. Here, too, are charts showing what I haveobserved up to date. Over there are the 'controls'--pigeons from thesame group which have been fed regularly on the usual diet so that Ican check my tests."

  Kennedy fell to examining the pigeons carefully as well as the chartsand records of feeding and results. None of the birds fed on what hadbeen taken from the apartment looked well, though some were worse thanothers.

  "I want you to observe this fellow," pointed out Leslie at last,singling out one cage. The pigeon in it was a pathetic figure. His eyesseemed dull and glazed. He paid little or no attention to us; even hisfood and water did not seem to interest him. Instead of struttingabout, he seemed to be positively wabbly on his feet. Kennedy examinedthis one longer and more carefully than any of the rest.

  "There are certainly all the symptoms of beriberi, or rather,polyneuritis, in pigeons, with that bird," admitted Craig, finally,looking up at Leslie.

  The commissioner seemed to be gratified. "You know," he remarked,"beriberi itself is a common disease in the Orient. There has been agood deal of study of it and the cause is now known to be the lack ofsomething in the food, which in the Orient is mostly rice. Polishingthe rice, which removes part of the outer coat, also takes awaysomething that is necessary for life, which scientists now call'vitamines.'"

  "I may take some of these samples to study myself?" interruptedKennedy, as though the story of vitamines was an old one to him.

  "By all means," agreed Leslie.

  Craig selected what he wanted, keeping each separate and marked, andexcused himself, saying that he had some investigations of his own thathe wished to make and would let Leslie know the result as soon as hediscovered anything.

  Kennedy did not go back directly to the laboratory, however. Instead,he went up-town and, to my surprise, stopped at one of the largebreweries. What it was that he was after I could not imagine, but,after a conference with the manager, he obtained several quarts ofbrewer's yeast, which he had sent directly down to the laboratory.

  Impatient though I was at this seeming neglect of the principal figuresin the case, I knew, nevertheless, that Kennedy had already schemed outhis campaign and that whatever it was he had in mind was of firstimportance.

  Back at last in his own laboratory, Craig set to work on the brewer'syeast, deriving something from it by the plentiful use of a liquidlabeled "Lloyd's reagent," a solution of hydrous aluminum silicate.

  After working for some time, I saw that he had obtained a solid whichhe pressed into the form of little whitish tablets. He had by no meansfinished, but, noticing my impatience, he placed the three or fourtablets in a little box and handed them to me.

  "You might take these over to Leslie in the department laboratory,Walter," he directed. "Tell him to feed them to that wabbly-lookingpigeon over there--and let me know the moment he observes any effect."

  Glad of the chance to occupy myself, I hastened on the errand, and evenpresided over the first feeding of the bird.

  When I returned I found that Kennedy had finished his work with thebrewer's yeast and was now devoting himself to the study of the varioussamples of food which he had obtained fro
m Leslie.

  He was just finishing a test of the baking-powder when I entered, andhis face showed plainly that he was puzzled by something that he haddiscovered.

  "What is it?" I asked. "Have you found out anything?"

  "This seems to be almost plain sodium carbonate," he replied,mechanically.

  "And that indicates?" I prompted.

  "Perhaps nothing, in itself," he went on, less abstractedly. "But theuse of sodium carbonate and other things which I have discovered inother samples disengages carbon dioxide at the temperature of bakingand cooking. If you'll look in that public-health report on my deskyou'll see how the latest investigations have shown that bicarbonate ofsoda and a whole list of other things which liberate carbon dioxidedestroy the vitamines Leslie was talking about. In other words, takenaltogether I should almost say there was evidence that a concertedeffort was being made to affect the food--a result analogous to that ofusing polished rice as a staple diet--and producing beriberi, or,perhaps more accurately, polyneuritis. I can be sure of nothing yet,but--it's worth following up."

  "Then you think Kato--"

  "Not too fast," cautioned Craig. "Remember, others had access to thekitchen, too."

  In spite of his hesitancy, I could think only of the two paragraphs wehad read in Mrs. Wardlaw's will, and especially of the last. Might notKato have been forced or enticed into a scheme that promised a safereturn and practically no chance of discovery? What gruesome mysteryhad been unveiled by the anonymous letter which had first excited ourcuriosity?

  It was late in the afternoon that Commissioner Leslie called us up,much excited, to inform us that the drooping pigeon was already peckingat food and beginning to show some interest in life. Kennedy seemedgreatly gratified as he hung up the receiver.

  "Almost dinner-time," he commented, with a glance at his watch. "Ithink we'll make another hurried visit to the Wardlaw apartment."

  We had no trouble getting in, although as outsiders we were moretolerated than welcome. Our excuse was that Kennedy had some morequestions which we wished to ask Miss Langdale.

  While we waited for her we sat, not in the study, but in the parlor.The folding-doors into the dining-room were closed, but across the hallwe could tell by the sound when Kato was in the kitchen and when hecrossed the hall.

  Once I heard him in the dining-room. Before I knew it Kennedy hadhastily tiptoed across the hall and into the kitchen. He was gone onlya couple of minutes, but it was long enough to place in the food thatwas being prepared, and in some unprepared, either the tablets he hadmade or a powder he had derived from them crushed up. When he returnedI saw from his manner that the real purpose of the visit had beenaccomplished, although when Miss Langdale appeared he went through theform of questioning her, mostly on Mrs. Marbury's sickness and death.He did not learn anything that appeared to be important, but at leasthe covered up the reason for his visit. Outside the apartment, Kennedypaused a moment. "There's nothing to do now but await developments," hemeditated. "Meanwhile, there is no use for us to double up our timetogether. I have decided to watch Kato to-night. Suppose you shadowDoctor Aitken. Perhaps we may get a line on something that way."

  The plan seemed admirable to me. In fact, I had been longing for someaction of the sort all the afternoon, while Kennedy had been engaged inthe studies which he evidently deemed more important.

  Accordingly, after dinner, we separated, Kennedy going back to theForum Apartments to wait until Kato left for the night, while I walkedfarther up the Drive to the address given in the directory as that ofDoctor Aitken.

  It happened to be the time when the doctor had his office hours forpatients, so that I was sure at least that he was at home when I tookmy station just down the street, carefully scrutinizing every one whoentered and left his house.

  Nothing happened, however, until the end of the hour during which hereceived office calls. As I glanced down the street I was glad that Ihad taken an inconspicuous post, for I could see Miss Langdaleapproaching. She was not in her nurse's uniform, but seemed to be offduty for an hour or two, and I must confess she was a striking figure,even in that neighborhood which was noted for its pretty and daintilygowned girls. Almost before I knew it she had entered theEnglish-basement entrance of Doctor Aitken's.

  I thought rapidly. What could be the purpose of her visit? Above all,how was I, on the outside, to find out? I walked down past the house.But that did no good. In a quandary, I stopped. Hesitation would get menothing. Suddenly an idea flashed through my mind. I turned in and rangthe bell.

  "It's past the doctor's office hours," informed a servant who openedthe door. "He sees no one after hours."

  "But," I lied, "I have an appointment. Don't disturb him. I can wait."

  The waiting-room was empty, I had seen, and I was determined to get inat any cost. Reluctantly the servant admitted me.

  For several moments I sat quietly alone, fearful that the doctor mightopen the double doors of his office and discover me. But nothinghappened and I grew bolder. Carefully I tiptoed to the door. It was ofsolid oak and practically impervious to sound. The doors fittedclosely, too. Still, by applying my ear, I could make out the sound ofvoices on the other side. I strained my ears both to catch a word nowand then and to be sure that I might hear the approach of anybodyoutside.

  Was Aitken suspiciously interested in the pretty nurse--or was shesuspiciously interested in him?

  Suddenly their voices became a trifle more distinct. "Then you thinkDoctor Wardlaw has it, too?" I heard her ask. I did not catch the exactreply, but it was in the affirmative.

  They were approaching the door. In a moment it would be opened. Iwaited to hear no more, but seized my hat and dashed for the entrancefrom the street just in time to escape observation. Miss Langdale cameout shortly, the doctor accompanying her to the door, and I followedher back to the Forum.

  What I had heard only added to the puzzle. Why her anxiety to knowwhether Wardlaw himself was affected? Why Aitken's solicitude inasserting that he was? Were they working together, or were they reallyopposed? Which might be using the other?

  My queries still unanswered, I returned to Aitken's and waited aboutsome time, but nothing happened, and finally I went on to our ownapartment.

  It was very late when Craig came in, but I was still awake and waitingfor him. Before I could ask him a question he was drawing from me whatI had observed, listening attentively. Evidently he considered it ofgreat importance, though no remark of his betrayed what interpretationhe put on the episode.

  "Have you found anything?" I managed to ask, finally.

  "Yes, indeed," he nodded, thoughtfully. "I shadowed Kato from theForum. It must have been before Miss Langdale came out that he left. Helives down-town in a tenement-house. There's something queer about thatJap."

  "I think there is," I agreed. "I don't like his looks."

  "But it wasn't he who interested me so much to-night," Craig went on,ignoring my remark, "as a woman."

  "A woman?" I queried, in surprise. "A Jap, too?"

  "No, a white woman, rather good-looking, too, with dark hair and eyes.She seemed to be waiting for him. Afterward I made inquiries. She hasbeen seen about there before."

  "Who was she?" I asked, fancying perhaps Miss Langdale had made anothervisit while she was out, although from the time it did not seempossible.

  "I followed her to her house. Her name is Hackstaff--"

  "The first trained nurse!" I exclaimed.

  "Miss Hackstaff is an enigma," confessed Kennedy. "At first I thoughtthat perhaps she might be one of those women whom the Oriental typefascinated, that she and Kato might be plotting. Then I have consideredthat perhaps her visits to Kato may be merely to get information--thatshe may have an ax to grind. Both Kato and she will bear watching, andI have made arrangements to have it done. I've called on that youngdetective, Chase, whom I've often used for the routine work ofshadowing. There's nothing more that we can do now until to-morrow, sowe might as well turn in."

  Early the next da
y Kennedy was again at work, both in his ownlaboratory and in that of the Health Department, making further studiesof the food and the effect it had on the pigeons, as well as observingwhat changes were produced by the white tablets he had extracted fromthe yeast.

  It was early in the forenoon when the buzzer on the laboratory doorsounded and I opened the door to admit Chase in a high state ofexcitement.

  "What has happened?" asked Craig, eagerly.

  "Many things," reported the young detective, breathlessly. "To beginwith, I followed Miss Hackstaff from her apartment this morning. Sheseemed to be worked up over something--perhaps had had a sleeplessnight. As nearly as I could make out she was going about aimlessly.Finally, however, I found that she was getting into the neighborhood ofDoctor Aitken and of the Forum. Well, when we got to the Forum shestopped and waited in front of it--oh, I should say almost half anhour. I couldn't make out what it was she wanted, but at last I foundout."

  He paused a moment, then raced on, without urging. "Miss Langdale cameout--and you should have seen the Hackstaff woman go for her." He drewin his breath sharply at the reminiscence. "I thought there was goingto be a murder done--on Riverside Drive. Miss Langdale screamed and ranback into the apartment. There was a good deal of confusion. Thehall-boys came to the rescue. In the excitement, I managed to slip intothe elevator with her. No one seemed to think it strange then that anoutsider should be interested. I went up with her--saw Wardlaw, as shepoured out the story. He's a queer one. Is he RIGHT?"

  "Why?" asked Craig, indulgently.

  "He seems so nervous; things upset him so easily. Yet, after we hadtaken care of Miss Langdale and matters had quieted down, I thought Imight get some idea of the cause of the fracas and asked him if he knewof any reason. Why, he looked at me kind of blankly, and I swear heacted as though he had almost forgotten it already. I tell you, he'snot RIGHT."

  Remembering our own experience, I glanced significantly at Craig."Korsakoff's syndrome?" I queried, laconically. "Another example of amind confused even on recent events?"

  Kennedy, however, was more interested in Chase. "What did MissHackstaff do?" he asked.

  "I don't know. I missed her. When I got out again she was gone."

  "Pick her up again," directed Craig. "Perhaps you'll get her at herplace. And see, this time, if you can get what I asked you."

  "I'll try," returned Chase, much pleased at the words of commendationwhich Craig added as he left us again.

  On what errand Chase had gone I could not guess, except that it hadsomething to do with this strange woman who had so unexpectedly enteredthe case. Nor was Craig any more communicative. There were evidentlymany problems which only events could clear up even in his mind. Thoughhe did not say anything, I knew that he was as impatient as I was, andas Leslie, too, who called up once or twice to learn whether he haddiscovered anything. There was nothing to do but wait.

  It was early in the afternoon that the telephone rang and I answeredit. It was Chase calling Kennedy. I heard only half the conversationand there was not much of that, but I knew that something was about tohappen. Craig hastily summoned a cab, then in rapid succession calledup Doctor Aitken and Leslie, for whom we stopped as our driver shot usover to the Forum Apartments.

  There was no ceremony or unnecessary explanation about our presence, asKennedy entered and directed Miss Langdale to bring her patients intothe little office-study of Doctor Wardlaw.

  Miss Langdale obeyed reluctantly. When she returned I felt that it wasappreciable that a change had taken place. Mrs. Wardlaw, at least, wasimproved. She was still ill, but she seemed to take a more livelyinterest in what was going on about her. As for Doctor Wardlaw,however, I could not see that there had been any improvement in him.His nervousness had not abated. Kato, whom Kennedy summoned at the sametime, preserved his usual imperturbable exterior. Miss Langdale, inspite of the incident of the morning, was quite as solicitous as everof her charges.

  We had not long to wait for Doctor Aitken. He arrived, inquiringanxiously what had happened, although Kennedy gave none of us anysatisfaction immediately as to the cause of his quick action. Aitkenfidgeted uneasily, glancing from Kennedy to Leslie, then to MissLangdale, and back to Kennedy, without reading any explanation in thefaces. I knew that Craig was secretly taking his time both for itseffect on those present and to give Chase a chance.

  "Our poisons and our drugs," he began, leisurely, at length, "are inmany instances the close relatives of harmless compounds that representthe intermediate steps in the daily process of metabolism. There ismuch that I might say about protein poisons. However, that is notexactly what I want to talk about--at least first."

  He stopped to make sure that he had the attention of us all. As amatter of fact, his manner was such that he attracted even the vagrantinterest of the Wardlaws.

  "I do not know how much of his suspicions Commissioner Leslie hascommunicated to you," he resumed, "but I believe that you have allheard of the disease beriberi so common in the Far East and known tothe Japanese as kakke. It is a form of polyneuritis and, as youdoubtless know, is now known to be caused, at least in the Orient, bythe removal of the pericarp in the polishing of rice. Our milling offlour is, in a minor degree, analogous. To be brief, the disease arisesfrom the lack in diet of certain substances or bodies which modernscientists call vitamines. Small quantities of these vital principlesare absolutely essential to normal growth and health and even to lifeitself. They are nitrogenous compounds and their absence gives rise toa class of serious disorders in which the muscles surrender their storeof nitrogen first. The nerves seems to be the preferred creditors, soto speak. They are affected only after the muscles begin to waste. Itis an abstruse subject and it is not necessary for me to go deeper intoit now."

  I controlled my own interest in order to watch those about me. Kato,for one, was listening attentively, I saw.

  "In my studies of the diet of this household," continued Kennedy, "Ihave found that substances have been used in preparing food which killvitamines. In short, the food has been denatured. Valuable elements,necessary elements, have been taken away."

  "I, sir, not always in kitchen, sir," interrupted Kato, stilldeferential. "I not always know--"

  With a peremptory wave of his hand Kennedy silenced the Jap.

  "It has long been a question," he hurried on, "whether these vitaminesare tangible bodies or just special arrangements of molecules. Recentlygovernment investigators have discovered that they are bodies that canbe isolated by a special process from the filtrate of brewer's yeast byLloyd's reagent. Five grams of this"--he held up some of the tablets hehad made--"for a sixty-kilogram person each day are sufficient. Unknownto you, I have introduced some of this substance into the food alreadydeficient in vitamines. I fancy that even now I can detect a change,"he nodded toward Mrs. Wardlaw.

  There was a murmur of surprise in the room, but before Craig couldcontinue further the door opened and Mrs. Wardlaw uttered a nervousexclamation. There stood Chase with a woman. I recognized herimmediately from Kennedy's description as Miss Hackstaff.

  Chase walked deliberately over to Kennedy and handed him something,while the nurse glanced calmly, almost with pity, at Mrs. Wardlaw,ignoring Wardlaw, then fixing her gaze venomously on Miss Langdale.Recalling the incident of the morning, I was ready to prevent, ifnecessary, a repetition now. Neither moved. But it was a thrilling, ifsilent, drama as the two women glared at each other.

  Kennedy was hastily comparing the anonymous note he had received withsomething Chase had brought.

  "Some one," he shot out, suddenly, looking up and facing us, "has, as Ihave intimated, been removing or destroying the vital principle in thefood--these vitamines. Clearly the purpose was to make this case looklike an epidemic of beriberi, polyneuritis. That part has been clear tome for some time. It has been the source of this devilish plot whichhas been obscure. Just a moment, Kato, I will do the talking. Mydetective, Chase, has been doing some shadowing for me, as well as someturning over of past history. He
has found a woman, a nurse, more thana nurse, a secret lover, cast off in favor of another. MissHackstaff--you wrote that letter--it is your hand--for revenge--on MissLangdale and--"

  "You shan't have him!" almost hissed Helen Hackstaff. "If I cannot--noone shall!"

  Natalie Langdale faced her, defiant. "You are a jealous, suspiciousperson," she cried. "Doctor Aitken knows--"

  "One moment," interrupted Craig. "Mrs. Marbury is gone. Mrs. Wardlaw isweakened. Yet all who are affected with nerve troubles are notnecessarily suffering from polyneuritis. Some one here has beendilettanting with death. It is of no use," he thundered, turningsuddenly on a cowering figure. "You stood to win most, with the moneyand your unholy love. But Miss Hackstaff, cast off, has proved yourNemesis. Your nervousness is the nervousness not of polyneuritis, butof guilt, Doctor Wardlaw!"