"Look at that!" he pointed out at last with the sharp tip of a pencil on one picture.

In what looked like an open space among some trees was a tiny figure of a man. It seemed as if he were hacking at something with an ax. What the something was did not appear in the picture.

"I should say that it was half a mile, perhaps a mile, farther away than that grove," commented Kennedy, making a rough calculation.

"On the old Davis farm," considered MacLeod. "Look and see if you can't make out the ruins of a house somewhere near-by. It was burned many years ago."

"Yes, yes," returned Kennedy, excitedly; "there's the place! Do you think we can get there in a car before it's dark?"

"Easily," replied MacLeod.

It was only a matter of minutes before we three were poking about in a tangle of wood and field, seeking to locate the spot where Kennedy's apparatus had photographed the lone axman.

At last, in a large, cleared field, we came upon a most peculiar heap of debris. As nearly as I could make out, it was a pile of junk, but most interesting junk. Practically all of it consisted in broken bits of the celluloid-like stuff we had seen in the abandoned building. Twisted inextricably about were steel wires and bits of all sorts of material. In the midst of the wreckage was something that looked for all the world like the remains of a gas-motor. It was not rusted, either, which indicated that it had been put there recently.

As he looked at it, Craig's face displayed a smile of satisfaction.

"Looks as though it might have been an aeroplane of the tractor type," he vouchsafed, finally.

"Surely there couldn't have been an accident," objected MacLeod. "No aviator could have lived through it, and there's no body."

"No; it was purposely destroyed," continued Craig. "It was landed here from somewhere else for that purpose. That was what the man in the picture was doing with the ax. After the last explosion something happened. He brought the machine here to destroy the evidence."

"But," persisted MacLeod, "if there had been an aeroplane hovering about we should have seen it in the air, passing over the works at the time of the explosion."

Kennedy picked the pieces, significantly.

"Some one about here has kept abreast of the times, if not ahead. See; the planes were of this non-inflammable celluloid that made it virtually transparent and visible only at a few hundred feet in the air. The aviator could fly low and so drop those pastilles accurately—and unseen. The engine had one of those new muffler- boxes. He would have been unheard, too, except for that delicate air-ship detector."

MacLeod and I could but stare at each other, aghast. Without a doubt it was in the old merry-go-round building that the phantom aviator had established his hangar. What the connection was between the tragedy in the Snedden family and the tragedy in the powder-works we did not know, but, at least, now we knew that there was some connection.

It was growing dark rapidly, and, with some difficulty, we retraced our steps to the point where we had left the car. We whirled back to the town, and, of course, to the Snedden house.

Snedden was sitting in the parlor when we arrived, by the body of his wife, staring, speechless, straight before him, while several neighbors were gathered about, trying to console him. We had scarcely entered when a messenger-boy came up the path from the gate. Both Kennedy and MacLeod turned toward him, expecting some reply to the numerous messages of alarm sent out earlier in the afternoon.

"Telegram for Mrs. Snedden," announced the boy.

"MRS. Snedden?" queried Kennedy, surprised, then quickly: "Oh yes, that's all right. I'll take care of it."

He signed for the message, tore it open, and read it. For a moment his face, which had been clouded, smoothed out, and he took a couple of turns up and down the hall, as though undecided. Finally he crumpled the telegram abstractedly and shoved it into his pocket. We followed him as he went into the parlor and stood for several moments, looking fixedly on the strangely flushed face of Mrs. Snedden. "MacLeod," he said, finally, turning gravely toward us, and, for the present, seeming to ignore the presence of the others, "this amazing series of crimes has brought home to me forcibly the alarming possibilities of applying modern scientific devices to criminal uses. New modes and processes seem to bring new menaces."

"Like carbon-monoxide poisoning?" suggested MacLeod. "Of course it has long been known as a harmful gas, but—"

"Let us see," interrupted Kennedy. "Walter, you were there when I examined Jackson's car. There was not a drop of gasolene in the tank, you will recall. Even the water in the radiator was low. I lifted the hood. Some one must have tampered with the carburetor. It was adjusted so that the amount of air in the mixture was reduced. More than that, I don't know whether you noticed it or not, but the spark and gas were set so that, when I did put gasolene in the tank, I had but to turn the engine over and it went. In other words, that car had been standing there, the engine running, until it simply stopped for want of fuel." He paused while we listened intently, then resumed. "The gas-engine and gas- motor have brought with them another of those unanticipated menaces of which I spoke. Whenever the explosion of the combustible mixture is incomplete or of moderated intensity a gas of which little is known may be formed in considerable quantities.

"In this case, as in several others that have come to my attention, vapors arising from the combustion must have emitted certain noxious products. The fumes that caused Ida Snedden's death were not of carbon monoxide from the stove, MacLeod. They were splitting-products of gasolene, which are so new to science that they have not yet been named.

"Mrs. Snedden's death, I may say for the benefit of the coroner, was due to the absorption of some of these unidentified gaseous poisons. They are as deadly as a knife-thrust through the heart, under certain conditions. Due to the non-oxidation of some of the elements of gasolene, they escape from the exhaust of every running gas-engine. In the open air, where only a whiff or two would be inhale now and then, they are not dangerous. But in a closed room they may kill in an incredibly short time. In fact, the condition has given rise to an entirely new phenomenon which some one has named 'petromortis.'"

"Petromortis?" repeated Snedden, who, for the first time, began to show interest in what was going on about him. "Then it was an accident?"

"I did not say it was an accident," corrected Craig. "There is an old adage that murder will out. And this expression of human experience is only repeated in what we modern scientific detectives are doing. No man bent on the commission of a crime can so arrange the circumstances of that crime that it will afterward appear, point by point, as an accident."

Kennedy had us all following him breathlessly now.

"I do not consider it an accident," he went on, rapidly piecing together the facts as we had found them. "Ida Snedden was killed because she was getting too close to some one's secret. Even at luncheon, I could see that she had discovered Gertrude's attachment for Garretson. How she heard that, following the excitement of the explosion this afternoon, Gertrude and Garretson had disappeared, I do not pretend to know. But it is evident that she did hear, that she went out and took Jackson's car, probably to pursue them. If we have heard that they went by the river road, she might have heard it, too.

"In all probability she came along just in time to surprise some one working on the other side of the old merry-go-round structure. There can be no reason to conceal the fact longer. From that deserted building some one was daily launching a newly designed invisible aeroplane. As Mrs. Snedden came along, she must have been just in time to see that person at his secret hangar. What happened I do not know, except that she must have run the car off the river road and into the building. The person whom she found must have suddenly conceived a method of getting her out of the way and making it look like an accident of some kind, perhaps persuaded her to stay in the car with the engine running, while he went off and destroyed the aeroplane which was damning evidence now."

Startling as was the revelation of an actual phantom destroyer, our minds were more aroused as to who might be the criminal who had employed such an engine of death.

Kennedy drew from his pocket the telegram which had just arrived, and spread it out flat before us on a table. It was dated Philadelphia, and read:

MRS. IDA SNEDDEN, Nitropolis:

Garretson and Gertrude were married to-day. Have traced them to the Wolcott. Try to reconcile Mr. Snedden.

HUNTER JACKSON.

I saw at once that part of the story. It was just a plain love- affair that had ended in an elopement at a convenient time. The fire-eating Garretson had been afraid of the Sneddens and Jackson, who was their friend. Before I could even think further, Kennedy had drawn out the films taken by the rocket-camera.

"With the aid of a magnifying-glass," he was saying, "I can get just enough of the lone figure in this picture to identify it. These are the crimes of a crazed pacifist, one whose mind had so long dwelt on the horrors of—"

"Look out!" shouted MacLeod, leaping in front of Kennedy.

The strain of the revelation had been too much. Snedden—a raving maniac—had reeled forward, wildly and impotently, at the man who had exposed him.



VI

THE BEAUTY MASK

"Oh, Mr. Jameson, if they could only wake her up—find out what is the matter—do something! This suspense is killing both mother and myself."

Scenting a good feature story, my city editor had sent me out on an assignment, my sole equipment being a clipping of two paragraphs from the morning Star.

GIRL IN COMA SIX DAYS—SHOWS NO SIGN OF REVIVAL

Virginia Blakeley, the nineteen-year-old daughter of Mrs. Stuart Blakeley, of Riverside Drive, who has been in a state of coma for six days, still shows no sign of returning consciousness.

Ever since Monday some member of her family has been constantly beside her. Her mother and sister have both vainly tried to coax her back to consciousness, but their efforts have not met with the slightest response. Dr. Calvert Haynes, the family physician, and several specialists who have been called in consultation, are completely baffled by the strange malady.

Often I had read of cases of morbid sleep lasting for days and even for weeks. But this was the first case I had ever actually encountered and I was glad to take the assignment.

The Blakeleys, as every one knew, had inherited from Stuart Blakeley a very considerable fortune in real estate in one of the most rapidly developing sections of upper New York, and on the death of their mother the two girls, Virginia and Cynthia, would be numbered among the wealthiest heiresses of the city.

They lived in a big sandstone mansion fronting the Hudson and it was with some misgiving that I sent up my card. Both Mrs. Blakeley and her other daughter, however, met me in the reception-room, thinking, perhaps, from what I had written on the card, that I might have some assistance to offer.

Mrs. Blakeley was a well-preserved lady, past middle-age, and very nervous.

"Mercy, Cynthia!" she exclaimed, as I explained my mission, "it's another one of those reporters. No, I cannot say anything—not a word. I don't know anything. See Doctor Haynes. I—"

"But, mother," interposed Cynthia, more calmly, "the thing is in the papers. It may be that some one who reads of it may know of something that can be done. Who can tell?"

"Well, I won't say anything," persisted the elder woman. "I don't like all this publicity. Did the newspapers ever do anything but harm to your poor dear father? No, I won't talk. It won't do us a bit of good. And you, Cynthia, had better be careful."

Mrs. Blakeley backed out of the door, but Cynthia, who was a few years older than her sister, had evidently acquired independence. At least she felt capable of coping with an ordinary reporter who looked no more formidable than myself.

"It is quite possible that some one who knows about such cases may learn of this," I urged.

She hesitated as her mother disappeared, and looked at me a moment, then, her feelings getting the better of her, burst forth with the strange appeal I have already quoted.

It was as though I had come at just an opportune moment when she must talk to some outsider to relieve her pent-up feelings.

By an adroit question here and there, as we stood in the reception-hall, I succeeded in getting the story, which seemed to be more of human interest than of news. I even managed to secure a photograph of Virginia as she was before the strange sleep fell on her.

Briefly, as her sister told it, Virginia was engaged to Hampton Haynes, a young medical student at the college where his father was a professor of diseases of the heart. The Hayneses were of a fine Southern family which had never recovered from the war and had finally come to New York. The father, Dr. Calvert Haynes, in addition to being a well-known physician, was the family physician of the Blakeleys, as I already knew. "Twice the date of the marriage has been set, only to be postponed," added Cynthia Blakeley. "We don't know what to do. And Hampton is frantic."

"Then this is really the second attack of the morbid sleep?" I queried.

"Yes—in a few weeks. Only the other wasn't so long—not more than a day."

She said it in a hesitating manner which I could not account for. Either she thought there might be something more back of it or she recalled her mother's aversion to reporters and did not know whether she was saying too much or not.

"Do you really fear that there is something wrong?" I asked, significantly, hastily choosing the former explanation.

Cynthia Blakeley looked quickly at the door through which her mother had retreated.

"I—I don't know," she replied, tremulously. "I don't know why I am talking to you. I'm so afraid, too, that the newspapers may say something that isn't true."

"You would like to get at the truth, if I promise to hold the story back?" I persisted, catching her eye.

"Yes," she answered, in a low tone, "but—" then stopped.

"I will ask my friend, Professor Kennedy, at the university, to come here," I urged.

"You know him?" she asked, eagerly. "He will come?"

"Without a doubt," I reassured, waiting for her to say no more, but picking up the telephone receiver on a stand in the hall.

Fortunately I found Craig at his laboratory and a few hasty words were all that was necessary to catch his interest.

"I must tell mother," Cynthia cried, excitedly, as I hung up the receiver. "Surely she cannot object to that. Will you wait here?"

As I waited for Craig, I tried to puzzle the case out for myself. Though I knew nothing about it as yet, I felt sure that I had not made a mistake and that there was some mystery here.

Suddenly I became aware that the two women were talking in the next room, though too low for me to catch what they were saying. It was evident, however, that Cynthia was having some difficulty in persuading her mother that everything was all right.

"Well, Cynthia," I heard her mother say, finally, as she left the room for one farther back, "I hope it will be all right—that is all I can say."

What was it that Mrs. Blakeley so feared? Was it merely the unpleasant notoriety? One could not help the feeling that there was something more that she suspected, perhaps knew, but would not tell. Yet, apparently, it was aside from her desire to have her daughter restored to normal. She was at sea, herself, I felt.

"Poor dear mother!" murmured Cynthia, rejoining me in a few moments. "She hardly knows just what it is she does want-except that we want Virginia well again."

We had not long to wait for Craig. What I had told him over the telephone had been quite enough to arouse his curiosity.

Both Mrs. Blakeley and Cynthia met him, at first a little fearfully, but quickly reassured by his manner, as well as my promise to see that nothing appeared in the Star which would be distasteful.

"Oh, if some one could only bring back our little girl!" cried Mrs. Blakeley, with suppressed emotion, leading the way with her daughter up-stairs.

It was only for a moment that I could see Craig alone to explain the impressions I had received, but it was enough.

"I'm glad you called me," he whispered. "There is something queer."

We followed them up to the dainty bedroom in flowered enamel where Virginia Blakeley lay, and it was then for the first time that we saw her. Kennedy drew a chair up beside the little white bed and went to work almost as though he had been a physician himself.

Partly from what I observed myself and partly from what he told me afterward, I shall try to describe the peculiar condition in which she was.

She lay there lethargic, scarcely breathing. Once she had been a tall, slender, fair girl, with a sort of wild grace. Now she seemed to be completely altered. I could not help thinking of the contrast between her looks now and the photograph in my pocket.

Not only was her respiration slow, but her pulse was almost imperceptible, less than forty a minute. Her temperature was far below normal, and her blood pressure low. Once she had seemed fully a woman, with all the strength and promise of precocious maturity. But now there was something strange about her looks. It is difficult to describe. It was not that she was no longer a young woman, but there seemed to be something almost sexless about her. It was as though her secondary sex characteristics were no longer feminine, but—for want of a better word—neuter.

Yet, strange to say, in spite of the lethargy which necessitated at least some artificial feeding, she was not falling away. She seemed, if anything, plump. To all appearances there was really a retardation of metabolism connected with the trance-like sleep. She was actually gaining in weight!

As he noted one of these things after another, Kennedy looked at her long and carefully. I followed the direction of his eyes. Over her nose, just a trifle above the line of her eyebrows, was a peculiar red mark, a sore, which was very disfiguring, as though it were hard to heal.

"What is that?" he asked Mrs. Blakeley, finally.

"I don't know," she replied, slowly. "We've all noticed it. It came just after the sleep began."

"You have no idea what could have caused it?"

"Both Virginia and Cynthia have been going to a face specialist," she admitted, "to have their skins treated for freckles. After the treatment they wore masks which were supposed to have some effect on the skin. I don't know. Could it be that?"

Kennedy looked sharply at Cynthia's face. There was no red mark over her nose. But there were certainly no freckles on either of the girls' faces now, either.

"Oh, mother," remonstrated Cynthia, "it couldn't be anything Doctor Chapelle did."

"Doctor Chapelle?" repeated Kennedy.

"Yes, Dr. Carl Chapelle," replied Mrs. Blakeley. "Perhaps you have heard of him. He is quite well known, has a beauty-parlor on Fifth Avenue. He—"

"It's ridiculous," cut in Cynthia, sharply. "Why, my face was worse than Virgie's. Car—He said it would take longer."

I had been watching Cynthia, but it needed only to have heard her to see that Doctor Chapelle was something more than a beauty specialist to her.

Kennedy glanced thoughtfully from the clear skin of Cynthia to the red mark on Virginia. Though he said nothing, I could see that his mind was on it. I had heard of the beauty doctors who promise to give one a skin as soft and clear as a baby's—and often, by their inexpert use of lotions and chemicals, succeed in ruining the skin and disfiguring the patient for life. Could this be a case of that sort? Yet how explain the apparent success with Cynthia?

The elder sister, however, was plainly vexed at the mention of the beauty doctor's name at all, and she showed it. Kennedy made a mental note of the matter, but refrained from saying any more about it.

"I suppose there is no objection to my seeing Doctor Haynes?" asked Kennedy, rising and changing the subject.

"None whatever," returned Mrs. Blakeley. "If there's anything you or he can do to bring Virginia out of this—anything safe—I want it done," she emphasized.

Cynthia was silent as we left. Evidently she had not expected Doctor Chapelle's name to be brought into the case.

We were lucky in finding Doctor Haynes at home, although it was not the regular time for his office hours. Kennedy introduced himself as a friend of the Blakeleys who had been asked to see that I made no blunders in writing the story for the Star. Doctor Haynes did not question the explanation.

He was a man well on toward the sixties, with that magnetic quality that inspires the confidence so necessary for a doctor. Far from wealthy, he had attained a high place in the profession.

As Kennedy finished his version of our mission, Doctor Haynes shook his head with a deep sigh.

"You can understand how I feel toward the Blakeleys," he remarked, at length. "I should consider it unethical to give an interview under any circumstances—much more so under the present."

"Still," I put in, taking Kennedy's cue, "just a word to set me straight can't do any harm. I won't quote you directly."

He seemed to realize that it might be better to talk carefully than to leave all to my imagination.

"Well," he began, slowly, "I have considered all the usual causes assigned for such morbid sleep. It is not auto-suggestion or trance, I am positive. Nor is there any trace of epilepsy. I cannot see how it could be due to poisoning, can you?"

I admitted readily that I could not.

"No," he resumed, "it is just a case of what we call narcolepsy— pathological somnolence—a sudden, uncontrollable inclination to sleep, occurring sometimes repeatedly or at varying intervals. I don't think it hysterical, epileptic, or toxemic. The plain fact of the matter, gentlemen, is that neither myself nor any of my colleagues whom I have consulted have the faintest idea what it is—yet."

The door of the office opened, for it was not the hour for consulting patients, and a tall, athletic young fellow, with a keen and restless face, though very boyish, entered.

"My son," the doctor introduced, "soon to be the sixth Doctor Haynes in direct line in the family."

We shook hands. It was evident that Cynthia had not by any means exaggerated when she said that he was frantic over what had happened to his fiancee.

Accordingly, there was no difficulty in reverting to the subject of our visit. Gradually I let Kennedy take the lead in the conversation so that our position might not seem to be false.

It was not long before Craig managed to inject a remark about the red spot over Virginia's nose. It seemed to excite young Hampton.

"Naturally I look on it more as a doctor than a lover," remarked his father, smiling indulgently at the young man, whom it was evident he regarded above everything else in the world. "I have not been able to account for it, either. Really the case is one of the most remarkable I have ever heard of."

"You have heard of a Dr. Carl Chapelle?" inquired Craig, tentatively.

"A beauty doctor," interrupted the young man, turning toward his father. "You've met him. He's the fellow I think is really engaged to Cynthia."

Hampton seemed much excited. There was unconcealed animosity in the manner of his remark, and I wondered why it was. Could there be some latent jealousy?

"I see," calmed Doctor Haynes. "You mean to infer that this—er— this Doctor Chapelle—" He paused, waiting for Kennedy to take the initiative.

"I suppose you've noticed over Miss Blakeley's nose a red sore?" hazarded Kennedy.

"Yes," replied Doctor Haynes, "rather refractory, too. I—"

"Say," interrupted Hampton, who by this time had reached a high pitch of excitement, "say, do you think it could be any of his confounded nostrums back of this thing?"

"Careful, Hampton," cautioned the elder man.

"I'd like to see him," pursued Craig to the younger. "You know him?"

"Know him? I should say I do. Good-looking, good practice, and all that, but—why, he must have hypnotized that girl! Cynthia thinks he's wonderful."

"I'd like to see him," suggested Craig.

"Very well," agreed Hampton, taking him at his word. "Much as I dislike the fellow, I have no objection to going down to his beauty-parlor with you."

"Thank you," returned Craig, as we excused ourselves and left the elder Doctor Haynes.

Several times on our journey down Hampton could not resist some reference to Chapelle for commercializing the profession, remarks which sounded strangely old on his lips.

Chapelle's office, we found, was in a large building on Fifth Avenue in the new shopping district, where hundreds of thousands of women passed almost daily. He called the place a Dermatological Institute, but, as Hampton put it, he practised "decorative surgery."

As we entered one door, we saw that patients left by another. Evidently, as Craig whispered, when sixty sought to look like sixteen the seekers did not like to come in contact with one another.

We waited some time in a little private room. At last Doctor Chapelle himself appeared, a rather handsome man with the manner that one instinctively feels appeals to the ladies.

He shook hands with young Haynes, and I could detect no hostility on Chapelle's part, but rather a friendly interest in a younger member of the medical profession.

Again I was thrown forward as a buffer. I was their excuse for being there. However, a newspaper experience gives you one thing, if no other—assurance.

"I believe you have a patient, a Miss Virginia Blakeley?" I ventured.

"Miss Blakeley? Oh yes, and her sister, also."

The mention of the names was enough. I was no longer needed as a buffer.

"Chapelle," blurted out Hampton, "you must have done something to her when you treated her face. There's a little red spot over her nose that hasn't healed yet."

Kennedy frowned at the impetuous interruption. Yet it was perhaps the best thing that could have happened.

"So," returned Chapelle, drawing back and placing his head on one side as he nodded it with each word, "you think I've spoiled her looks? Aren't the freckles gone?"

"Yes," retorted Hampton, bitterly, "but on her face is this new disfigurement."

"That?" shrugged Chapelle. "I know nothing of that—nor of the trance. I have only my specialty."

Calm though he appeared outwardly, one could see that Chapelle was plainly worried. Under the circumstances, might not his professional reputation be at stake? What if a hint like this got abroad among his rich clientele?

I looked about his shop and wondered just how much of a faker he was. Once or twice I had heard of surgeons who had gone legitimately into this sort of thing. But the common story was that of the swindler—or worse. I had heard of scores of cases of good looks permanently ruined, seldom of any benefit. Had Chapelle ignorantly done something that would leave its scar forever? Or was he one of the few who were honest and careful?

Whatever the case, Kennedy had accomplished his purpose. He had seen Chapelle. If he were really guilty of anything the chances were all in favor of his betraying it by trying to cover it up. Deftly suppressing Hampton, we managed to beat a retreat without showing our hands any further.

"Humph!" snorted Hampton, as we rode down in the elevator and hopped on a 'bus to go up-town. "Gave up legitimate medicine and took up this beauty doctoring—it's unprofessional, I tell you. Why, he even advertises!"

We left Hampton and returned to the laboratory, though Craig had no present intention of staying there. His visit was merely for the purpose of gathering some apparatus, which included a Crookes tube, carefully packed, a rheostat, and some other paraphernalia which we divided. A few moments later we were on our way again to the Blakeley mansion.

No change had taken place in the condition of the patient, and Mrs. Blakeley met us anxiously. Nor was the anxiety wholly over her daughter's condition, for there seemed to be an air of relief when Kennedy told her that we had little to report.

Up-stairs in the sick-room, Craig set silently to work, attaching his apparatus to an electric-light socket from which he had unscrewed the bulb. As he proceeded I saw that it was, as I had surmised, his new X-ray photographing machine which he had brought. Carefully, from several angles, he took photographs of Virginia's head, then, without saying a word, packed up his kit and started away.

We were passing down the hall, after leaving Mrs. Blakeley, when a figure stepped out from behind a portiere. It was Cynthia, who had been waiting to see us alone.

"You—don't think Doctor Chapelle had anything to do with it?" she asked, in a hoarse whisper.

"Then Hampton Haynes has been here?" avoided Kennedy.

"Yes," she admitted, as though the question had been quite logical. "He told me of your visit to Carl."

There was no concealment, now, of her anxiety. Indeed, I saw no reason why there should be. It was quite natural that the girl should worry over her lover, if she thought there was even a haze of suspicion in Kennedy's mind.

"Really I have found out nothing yet," was the only answer Craig gave, from which I readily deduced that he was well satisfied to play the game by pitting each against all, in the hope of gathering here and there a bit of the truth. "As soon as I find out anything I shall let you and your mother know. And you must tell me everything, too."

He paused to emphasize the last words, then slowly turned again toward the door. From the corner of my eye I saw Cynthia take a step after him, pause, then take another.

"Oh, Professor Kennedy," she called.

Craig turned.

"There's something I forgot," she continued. "There's something wrong with mother!" She paused, then resumed: "Even before Virginia was taken down with this—illness I saw a change. She is worried. Oh, Professor Kennedy, what is it? We have all been so happy. And now—Virgie, mother—all I have in the world. What shall I do?"

"Just what do you mean?" asked Kennedy, gently.

"I don't know. Mother has been so different lately. And now, every night, she goes out."

"Where?" encouraged Kennedy, realizing that his plan was working.

"I don't know. If she would only come back looking happier." She was sobbing, convulsively, over she knew not what.

"Miss Blakeley," said Kennedy, taking her hand between both of his, "only trust me. If it is in my power I shall bring you all out of this uncertainty that haunts you."

She could only murmur her thanks as we left.

"It is strange," ruminated Kennedy, as we sped across the city again to the laboratory. "We must watch Mrs. Blakeley."

That was all that was said. Although I had no inkling of what was back of it all, I felt quite satisfied at having recognized the mystery even on stumbling on it as I had.

In the laboratory, as soon as he could develop the skiagraphs he had taken, Kennedy began a minute study of them. It was not long before he looked over at me with the expression I had come to recognize when he found something important. I went over and looked at the radiograph which he was studying. To me it was nothing but successive gradations of shadows. But to one who had studied roentgenography as Kennedy had each minute gradation of light and shade had its meaning.

"You see," pointed out Kennedy, tracing along one of the shadows with a fine-pointed pencil, and then along a corresponding position on another standard skiagraph which he already had, "there is a marked diminution in size of the sella turcica, as it is called. Yet there is no evidence of a tumor." For several moments he pondered deeply over the photographs. "And it is impossible to conceive of any mechanical pressure sufficient to cause such a change," he added.

Unable to help him on the problem, whatever it might be, I watched him pacing up and down the laboratory.

"I shall have to take that picture over again—under different circumstances," he remarked, finally, pausing and looking at his watch. "To-night we must follow this clue which Cynthia has given us. Call a cab, Walter."

We took a stand down the block from the Blakeley mansion, near a large apartment, where the presence of a cab would not attract attention. If there is any job I despise it is shadowing. One must keep his eyes riveted on a house, for, once let the attention relax and it is incredible how quickly any one may get out and disappear.

Our vigil was finally rewarded when we saw Mrs. Blakeley emerge and hurry down the street. To follow her was easy, for she did not suspect that she was being watched, and went afoot. On she walked, turning off the Drive and proceeding rapidly toward the region of cheap tenements. She paused before one, and as our cab cruised leisurely past we saw her press a button, the last on the right- hand side, enter the door, and start up the stairs.

Instantly Kennedy signaled our driver to stop and together we hopped out and walked back, cautiously entering the vestibule. The name in the letter-box was "Mrs. Reba Rinehart." What could it mean?

Just then another cab stopped up the street, and as we turned to leave the vestibule Kennedy drew back. It was too late, however, not to be seen. A man had just alighted and, in turn, had started back, also realizing that it was too late. It was Chapelle! There was nothing to do but to make the best of it.

"Shadowing the shadowers?" queried Kennedy, keenly watching the play of his features under the arc-light of the street.

"Miss Cynthia asked me to follow her mother the other night," he answered, quite frankly. "And I have been doing so ever since."

It was a glib answer, at any rate, I thought.

"Then, perhaps you know something of Reba Rinehart, too," bluffed Kennedy.

Chapelle eyed us a moment, in doubt how much we knew. Kennedy played a pair of deuces as if they had been four aces instead.

"Not much," replied Chapelle, dubiously. "I know that Mrs. Blakeley has been paying money to the old woman, who seems to be ill. Once I managed to get in to see her. It's a bad case of pernicious anemia, I should say. A neighbor told me she had been to the college hospital, had been one of Doctor Haynes's cases, but that he had turned her over to his son. I've seen Hampton Haynes here, too."

There was an air of sincerity about Chapelle's words. But, then, I reflected that there had also been a similar ring to what we had heard Hampton say. Were they playing a game against each other? Perhaps—but what was the game? What did it all mean and why should Mrs. Blakeley pay money to an old woman, a charity patient?

There was no solution. Both Kennedy and Chapelle, by a sort of tacit consent, dismissed their cabs, and we strolled on over toward Broadway, watching one another, furtively. We parted finally, and Craig and I went up to our apartment, where he sat for hours in a brown study. There was plenty to think about even so far in the affair. He may have sat up all night. At any rate, he roused me early in the morning.

"Come over to the laboratory," he said. "I want to take that X-ray machine up there again to Blakeley's. Confound it! I hope it's not too late."

I lost no time in joining him and we were at the house long before any reasonable hour for visitors.

Kennedy asked for Mrs. Blakeley and hurriedly set up the X-ray apparatus. "I wish you would place that face mask which she was wearing exactly as it was before she became ill," he asked.

Her mother did as Kennedy directed, replacing the rubber mask as Virginia had worn it.

"I want you to preserve that mask," directed Kennedy, as he finished taking his pictures. "Say nothing about it to any one. In fact, I should advise putting it in your family safe for the present."

Hastily we drove back to the laboratory and Kennedy set to work again developing the second set of skiagraphs. I had not long to wait, this time, for him to study them. His first glance brought me over to him as he exclaimed loudly.

At the point just opposite the sore which he had observed on Virginia's forehead, and overlying the sella turcica, there was a peculiar spot on the radiograph.

"Something in that mask has affected the photographic plate," he explained, his face now animated.

Before I could ask him what it was he had opened a cabinet where he kept many new things which he studied in his leisure moments. From it I saw him take several glass ampules which he glanced at hastily and shoved into his pocket as we heard a footstep out in the hall. It was Chapelle, very much worried. Could it be that he knew his society clientele was at stake, I wondered. Or was it more than that?

"She's dead!" he cried. "The old lady died last night!"

Without a word Kennedy hustled us out of the laboratory, stuffing the X-ray pictures into his pocket, also, as we went.

As we hurried down-town Chapelle told us how he had tried to keep a watch by bribing one of the neighbors, who had just informed him of the tragedy.

"It was her heart," said one of the neighbors, as we entered the poor apartment. "The doctor said so."

"Anemia," insisted Chapelle, looking carefully at the body.

Kennedy bent over, also, and examined the poor, worn frame. As he did so he caught sight of a heavy linen envelope tucked under her pillow. He pulled it out gently and opened it. Inside were several time-worn documents and letters. He glanced over them hastily, unfolding first a letter.

"Walter," he whispered, furtively, looking at the neighbors in the room and making sure that none of them had seen the envelope already. "Read these. That's her story."

One glance was sufficient. The first was a letter from old Stuart Blakeley. Reba Rinehart had been secretly married to him—and never divorced. One paper after another unfolded her story.

I thought quickly. Then she had had a right in the Blakeley millions. More than that, the Blakeleys themselves had none, at least only what came to them by Blakeley's will.

I read on, to see what, if any, contest she had intended to make. And as I read I could picture old Stuart Blakeley to myself— strong, direct, unscrupulous, a man who knew what he wanted and got it, dominant, close-mouthed, mysterious. He had understood and estimated the future of New York. On that he had founded his fortune.

According to the old lady's story, the marriage was a complete secret. She had demanded marriage when he had demanded her. He had pointed out the difficulties. The original property had come to him and would remain in his hands only on condition that he married one of his own faith. She was not of the faith and declined to become so. There had been other family reasons, also. They had been married, with the idea of keeping it secret until he could arrange his affairs so that he could safely acknowledge her.

It was, according to her story, a ruse. When she demanded recognition he replied that the marriage was invalid, that the minister had been unfrocked before the ceremony. She was not in law his wife and had no claim, he asserted. But he agreed to compromise, in spite of it all. If she would go West and not return or intrude, he would make a cash settlement. Disillusioned, she took the offer and went to California. Somehow, he understood that she was dead. Years later he married again.

Meanwhile she had invested her settlement, had prospered, had even married herself, thinking the first marriage void. Then her second husband died and evil times came. Blakeley was dead, but she came East. Since then she had been fighting to establish the validity of the first marriage and hence her claim to dower rights. It was a moving story.

As we finished reading, Kennedy gathered the papers together and took charge of them. Taking Chapelle, who by this time was in a high state of excitement over both the death and the discovery, Kennedy hurried to the Blakeley mansion, stopping only long enough to telephone to Doctor Haynes and his son.

Evidently the news had spread. Cynthia Blakeley met us in the hall, half frightened, yet much relieved.

"Oh, Professor Kennedy," she cried, "I don't know what it is, but mother seems so different. What is it all about?"

As Kennedy said nothing, she turned to Chapelle, whom I was watching narrowly. "What is it, Carl?" she whispered.

"I—I can't tell," he whispered back, guardedly. Then, with an anxious glance at the rest of us, "Is your sister any better?"

Cynthia's face clouded. Relieved though she was about her mother, there was still that horror for Virginia.

"Come," I interrupted, not wishing to let Chapelle get out of my sight, yet wishing to follow Kennedy, who had dashed up-stairs.

I found Craig already at the bedside of Virginia. He had broken one of the ampules and was injecting some of the extract in it into the sleeping girl's arm. Mrs. Blakeley bent over eagerly as he did so. Even in her manner she was changed. There was anxiety for Virginia yet, but one could feel that a great weight seemed to be lifted from her.

So engrossed was I in watching Kennedy that I did not hear Doctor Haynes and Hampton enter. Chapelle heard, however, and turned.

For a moment he gazed at Hampton. Then with a slight curl of the lip he said, in a low tone, "Is it strictly ethical to treat a patient for disease of the heart when she is suffering from anemia—if you have an interest in the life and death of the patient?"

I watched Hampton's face closely. There was indignation in every line of it. But before he could reply Doctor Haynes stepped forward.

"My son was right in the diagnosis," he almost shouted, shaking a menacing finger at Chapelle. "To come to the point, sir, explain that mark on Miss Virginia's forehead!"

"Yes," demanded Hampton, also taking a step toward the beauty doctor, "explain it—if you dare."

Cynthia suppressed a little cry of fear. For a moment I thought that the two young men would forget everything in the heat of their feelings.

"Just a second," interposed Kennedy, quickly stepping between them. "Let me do the talking." There was something commanding about his tone as he looked from one to the other of us.

"The trouble with Miss Virginia," he added, deliberately, "seems to lie in one of what the scientists have lately designated the 'endocrine glands'—in this case the pituitary. My X-ray pictures show that conclusively.

"Let me explain for the benefit of the rest. The pituitary is an oval glandular body composed of two lobes and a connecting area, which rest in the sella turcica, enveloped by a layer of tissue, about under this point." He indicated the red spot on her forehead as he spoke. "It is, as the early French surgeons called it, l'organe enigmatique. The ancients thought it discharged the pituita, or mucus, into the nose. Most scientists of the past century asserted that it was a vestigial relic of prehistoric usefulness. To-day we know better.

"One by one the functions of the internal secretions are being discovered. Our variously acquired bits of information concerning the ductless glands lie before us like the fragments of a modern picture puzzle. And so, I may tell you, in connection with recent experimental studies of the role of the pituitary, Doctor Cushing and other collaborators at Johns Hopkins have noticed a marked tendency to pass into a profoundly lethargic state when the secretion of the pituitary is totally or nearly so removed."

Kennedy now had every eye riveted on him as he deftly led the subject straight to the case of the poor girl before us.

"This," he added, with a wave of his hand toward her, "is much like what is called the Frohlich syndrome—the lethargy, the subnormal temperature, slow pulse, and respiration, lowered blood pressure, and insensitivity, the growth of fat and the loss of sex characteristics. It has a name—dystrophia adiposogenitalis."

He nodded to Doctor Haynes, but did not pause. "This case bears a striking resemblance to the pronounced natural somnolence of hibernation. And induced hypopituitarism—under activity of the gland—produces a result just like natural hibernation. Hibernation has nothing to do with winter, or with food, primarily; it is connected in some way with this little gland under the forehead.

"As the pituitary secretion is lessened, the blocking action of the fatigue products in the body be-comes greater and morbid somnolence sets in. There is a high tolerance of carbohydrates which are promptly stored as fat. I am surprised, Doctor Haynes, that you did not recognize the symptoms."

A murmur from Mrs. Blakeley cut short Doctor Haynes's reply. I thought I noticed a movement of the still face on the white bed.

"Virgie! Virgie!" called Mrs. Blakeley, dropping on her knee beside her daughter.

"I'm here—mother!"

Virginia's eyes opened ever so slightly. Her face turned just an inch or two. She seemed to be making a great effort, but it lasted only a moment. Then she slipped back into the strange condition that had baffled skilled physicians and surgeons for nearly a week.

"The sleep is being dispelled," said Kennedy, quietly placing his hand on Mrs. Blakeley's shoulder. "It is a sort of semi- consciousness now and the improvement should soon be great."

"And that?" I asked, touching the empty ampule from which he had injected the contents into her.

"Pituitrin—the extract of the anterior lobe of the pituitary body. Some one who had an object in removing her temporarily probably counted on restoring her to her former blooming womanhood by pituitrin—and by removing the cause of the trouble."

Kennedy reached into his pocket and drew forth the second X-ray photograph he had taken. "Mrs. Blakeley, may I trouble you to get that beauty mask which your daughter wore?"

Mechanically Mrs. Blakeley obeyed. I expected Chapelle to object, but not a word broke the death-like stillness.

"The narcolepsy," continued Kennedy, taking the mask, "was due, I find, to something that affected the pituitary gland. I have here a photograph of her taken when she was wearing the mask." He ran his finger lightly over the part just above the eyes. "Feel that little lump, Walter," he directed.

I did so. It was almost imperceptible, but there was something.

"What is it?" I asked.

"Located in one of the best protected and most inaccessible parts of the body," Kennedy considered, slowly, "how could the pituitary be reached? If you will study my skiagraph, you will see how I got my first clue. There was something over that spot which caused the refractory sore. What was it? Radium—carefully placed in the mask with guards of lead foil in such a way as to protect the eyes, but direct the emission full at the gland which was to be affected, and the secretions stopped."

Chapelle gave a gasp. He was pale and agitated.

"Some of you have already heard of Reba Rinehart," shot out Kennedy, suddenly changing the subject.

Mrs. Blakeley could not have been more astounded if a bomb had dropped before her. Still kneeling before Virginia's bed, she turned her startled face at Kennedy, clasping her hands in appeal.

"It was for my girls that I tried to buy her off—for their good name—their fortune—their future," she cried, imploringly.

Kennedy bent down, "I know that is all," he reassured, then, facing us, went on: "Behind that old woman was a secret of romantic interest. She was contemplating filing suit in the courts to recover a widow's interest in the land on which now stand the homes of millionaires, hotel palaces, luxurious apartments, and popular theaters—millions of dollars' worth of property."

Cynthia moved over and drew her arms about the convulsed figure of her mother.

"Some one else knew of this old marriage of Stuart Blakeley," proceeded Kennedy, "knew of Reba Rinehart, knew that she might die at any moment. But until she died none of the Blakeleys could be entirely sure of their fortune."

It flashed over me that Chapelle might have conceived the whole scheme, seeking to gain the entire fortune for Cynthia.

"Who was interested enough to plot this postponement of the wedding until the danger to the fortune was finally removed?" I caught sight of Hampton Haynes, his eyes riveted on the face on the bed before us.

Virginia stirred again. This time her eyes opened wider. As if in a dream she caught sight of the face of her lover and smiled wanly.

Could it have been Hampton? It seemed incredible.

"The old lady is dead," pursued Kennedy, tensely. "Her dower right died with her. Nothing can be gained by bringing her case back again—except to trouble the Blakeleys in what is rightfully theirs."

Gathering up the beauty mask, the X-ray photographs, and the papers of Mrs. Rinehart, Kennedy emphasized with them the words as he whipped them out suddenly.

"Postponing the marriage, at the possible expense of Chapelle, until Reba Rinehart was dead, and trusting to a wrong diagnosis and Hampton's inexperience as the surest way of bringing that result about quickly, it was your inordinate ambition for your son, Doctor Haynes, that led you on. I shall hold these proofs until Virginia Blakeley is restored completely to health and beauty."



VII

THE LOVE METER

"Since we brought him home, my brother just tosses and gasps for air. Oh, I think Eulalie and I shall both go mad!"

The soft, pleading voice of Anitra Barrios and her big, appealing brown eyes filled with tears were doubly affecting as, in spite of her own feelings, she placed her hand on that of a somewhat younger girl who had accompanied her to the laboratory.

"We were to have been married next month," sobbed Eulalie Sandoval. "Can't you come and see Jose, Professor Kennedy? There must be something you can do. We fear he is dying—yes, dying."

"Poor little girl!" murmured Anitra, still patting her hand affectionately, then to us, "You know, Eulalie is the sister of Manuel Sandoval, who manages the New York business of my brother." She paused. "Oh, I can't believe it, myself. It's all so strange, so sudden."

For the moment her own grief overwhelmed Anitra, and both sister and sweetheart of Jose Barrios clung to each other.

"What is the trouble?" soothed Craig. "What has happened? How can I help you?"

"Everything was so happy with us," cried Anitra, "until Jose and I came to New York—and—now—" She broke down again.

"Please be calm," encouraged Kennedy. "Tell me everything— anything."

With an effort Anitra began again. "It was last night—quite late— at his office at the foot of Wall Street—he was there alone," she strove to connect her broken thoughts. "Some one—I think it must have been the janitor—called me up at home and said that my brother was very ill. Eulalie was there with me. We hurried down to him. When we got there Jose was on the floor by his desk, unconscious, struggling for breath, just as he is now." "Did you observe anything peculiar?" queried Kennedy. "Was there anything that might give you a hint of what had happened?"

Anitra Barrios considered. "Nothing," she replied, slowly, "except that the windows were all closed. There was a peculiar odor in the room. I was so excited over Jose, though, that I couldn't tell you just what it was like."

"What did you do?" inquired Craig.

"What could we do, just two girls, all alone? It was late. The streets were deserted. You know how they are down-town at night. We took him home, to the hotel, in a cab, and called the hotel physician, Doctor Scott."

Both girls were again weeping silently in each other's arms. If there was anything that moved Kennedy to action it was distress of this sort. Without a word he rose from his desk, and I followed him. Anitra and Eulalie seemed to understand. Though they said nothing, they looked their gratitude as we four left the laboratory.

On the way down to the hotel Anitra continued to pour out her story in a fragmentary way. Her brother and she, it seemed, had inherited from their father a large sugar-plantation in Santa Clara, the middle province of Cuba.

Jose had not been like many of the planters. He had actually taken hold of the plantation, after the revolution had wrecked it, and had re-established it on modern, scientific lines. Now it was one of the largest independent plantations on the island.

To increase its efficiency, he had later established a New York office to look after the sale of the raw sugar and had placed it in charge of a friend, Manuel Sandoval. A month or so before he had come to New York with his sister to sell the plantation, to get the high price that the boom in sugar had made it worth. It was while he had been negotiating for the sale that he had fallen in love with Eulalie and they had become engaged.

Doctor Scott met us in the sitting-room of the suite which Anitra and her brother occupied, and, as she introduced us, with an anxious glance in the direction of the door of the sick-room, he shook his head gravely, though he did his best to seem encouraging.

"It's a case of poisoning of some kind, I fear," he whispered aside to us, at the first opportunity. "But I can't quite make out just what it is."

We followed the doctor into the room. Eulalie had preceded us and had dropped down on her knees by the bed, passing her little white hand caressingly over the pale and distorted face of Jose.

He was still unconscious, gasping and fighting for breath, his features pinched and skin cold and clammy. Kennedy examined the stricken man carefully, first feeling his pulse. It was barely perceptible, rapid, thready, and irregular. Now and then there were muscular tremblings and convulsive movements of the limbs. Craig moved over to the side of the room away from the two girls, where Doctor Scott was standing.

"Sometimes," I heard the doctor venture, "I think it is aconite, but the symptoms are not quite the same. Besides, I don't see how it could have been administered. There's no mark on him that might have come from a hypodermic, no wound, not even a scratch. He couldn't have swallowed it. Suicide is out of the question. But his nose and throat are terribly swollen and inflamed. It's beyond me."

I tried to recall other cases I had seen. There was one case of Kennedy's in which several deaths had occurred due to aconite. Was this another of that sort? I felt unqualified to judge, where Doctor Scott himself confessed his inability. Kennedy himself said nothing, and from his face I gathered that even he had no clue as yet.

As we left the sick-room, we found that another visitor had arrived and was standing in the sitting-room. It was Manuel Sandoval.

Sandoval was a handsome fellow, tall, straight as an arrow, with bushy dark hair and a mustache which gave him a distinguished appearance. Born in Cuba, he had been educated in the United States, had taken special work in the technology of sugar, knew the game from cane to centrifugal and the ship to the sugar trust. He was quite as much a scientist as a business man.

He and Eulalie talked for a moment in low tones in Cuban Spanish, but it needed only to watch his eyes to guess where his heart was. He seemed to fairly devour every move that Anitra made about the apartment.

A few minutes later the door opened again and a striking-looking man entered. He was a bit older than Sandoval, but still young. As he entered he bowed to Sandoval and Eulalie but greeted Anitra warmly.

"Mr. Burton Page," introduced Anitra, turning to us quickly, with just the trace of a flush on her face. "Mr. Page has been putting my brother in touch with people in New York who are interested in Cuban sugar-plantations." A call from Doctor Scott for some help took both girls into the sick-room for a moment.

"Is Barrios any better?" asked Page, turning to Sandoval.

Sandoval shook his head in the negative, but said nothing. One could not help observing that there seemed to be a sort of antipathy between the two, and I saw that Craig was observing them both closely.

Page was a typical, breezy Westerner, who had first drifted to New York as a mining promoter. Prom that he had gone into selling ranches, and, by natural stages, into the promotion of almost anything in the universe.

Sugar being at the time uppermost in the mind of the "Street," Page was naturally to be found crammed with facts about that staple. One could not help being interested in studying a man of his type, as long as one kept his grip on his pocket-book. For he was a veritable pied piper when it came to enticing dollars to follow him, and in his promotions he had the reputation of having amassed an impressive pile of dollars himself.

No important change in the condition of Barrios had taken place, except that he was a trifle more exhausted, and Doctor Scott administered a stimulant. Kennedy, who was eager to take up the investigation of the case on the outside in the hope of discovering something that might be dignified into being a clue, excused himself, with a nod to Anitra to follow into the hall.

"I may look over the office?" Craig ventured when we were alone with her.

"Surely," she replied, frankly, opening her handbag which was lying on a table near the door. "I have an equal right in the business with my brother. Here are the keys. The office has been closed to-day."

Kennedy took the keys, promising to let her know the moment he discovered anything important, and we hurried directly down-town.

The office of the Barrios Company was at the foot of Wall Street, where the business of importing touched on the financial district. From the window one could see freighters unloading their cargoes at the docks. In the other direction, capital to the billions was represented. But in all that interesting neighborhood nothing just at present could surpass the mystery of what had taken place in the lonely little office late the night before.

Kennedy passed the rail that shut the outer office off from a sort of reception space. He glanced about at the safe, the books, papers, and letter-files. It would take an accountant and an investigator days, perhaps weeks, to trace out anything in them, if indeed it were worth while at all.

Two glass doors opened at one end to two smaller private offices, one belonging evidently to Sandoval, the other to Barrios. What theory Craig formed I could not guess, but as he tiptoed from the hall door, past the rail, to the door of Jose's office, I could see that first of all he was trying to discover whether it was possible to enter the outer office and reach Jose's door unseen and unheard by any one sitting at the desk inside. Apparently it was easily possible, and he paused a moment to consider what good that knowledge might do.

As he did so his eye rested on the floor. A few feet away stood one of the modern "sanitary" desks. In this case the legs of the desk raised the desk high enough from the floor so that one could at least see where the cleaning-woman had left a small pile of unsanitary dust near the wall.

Suddenly Kennedy bent down and poked something out of the pile of dust. There on the floor was an empty shell of a cartridge. Kennedy picked it up and looked at it curiously.

What did it mean? I recalled that Doctor Scott had particularly said that Barrios had not been wounded.

Still regarding the cartridge shell, Kennedy sat down at the desk of Barrios.

Looking for a piece of paper in which to wrap the shell, he pulled out the middle drawer of the desk. In a back corner was a package of letters, neatly tied. We glanced at them. The envelopes bore the name of Jose Barrios and were in the handwriting of a woman. Some were postmarked Cuba; others, later, New York. Kennedy opened one of them.

I could not restrain an exclamation of astonishment. I had expected that they were from Eulalie Sandoval. But they were signed by a name that we had not heard—Teresa de Leon!

Hastily Kennedy read through the open letter. Its tone seemed to be that of a threat. One sentence I recall was, "I would follow you anywhere—I'll make you want me."

One after another Kennedy ran through them. All were vague and veiled, as though the writer wished by some circumlocution to convey an idea that would not be apparent to some third, inquisitive party.

What was back of it all? Had Jose been making love to another woman at the same time that he was engaged to Eulalie Sandoval? As far as the contents of the letters went there was nothing to show that he had done anything wrong. The mystery of the "other woman" only served to deepen the mystery of what little we already knew.

Craig dropped the letters into his pocket along with the shell, and walked around into the office of Sandoval. I followed him. Quickly he made a search, but it did not seem to net him anything.

Meanwhile I had been regarding a queer-looking instrument that stood on a flat table against one wall. It seemed to consist of a standard on each end of which was fastened a disk, besides several other arrangements the purpose of which I had not the slightest idea. Between the two ends rested a glass tube of some liquid. At one end was a lamp; the other was fitted with an eyepiece like a telescope. Beside the instrument on the table lay some more glass- capped tubes and strewn about were samples of raw sugar.

"It is a saccharimeter," explained Kennedy, also looking at it, "an instrument used to detect the amount of sugar held in solution, a form of the polariscope. We won't go into the science of it now. It's rather abstruse."

He was about to turn back into the outer office when an idea seemed to occur to him. He took the cartridge from his pocket and carefully scraped off what he could of the powder that still adhered to the outer rim. It was just a bit, but he dissolved it in some liquid from a bottle on the table, filled one of the clean glass tubes, capped the open end, and placed this tube in the saccharimeter where the first one I noticed had been.

Carefully he lighted the lamp, then squinted through the eyepiece at the tube of liquid containing what he had derived from the cartridge. He made some adjustments, and as he did so his face indicated that at last he began to see something dimly. The saccharimeter had opened the first rift in the haze that surrounded the case.

"I think I know what we have here," he said, briefly, rising and placing the tube and its contents in his pocket with the other things he had discovered. "Of course it is only a hint. This instrument won't tell me finally. But it is worth following up."

With a final glance about to make sure that we had overlooked nothing, Kennedy closed and locked the outside door.

"I'm going directly up to the laboratory, Walter," decided Kennedy. "Meanwhile you can help me very much if you will look up this Teresa de Leon. I noticed that the New York letters were written on the stationery of the Pan-America Hotel. Get what you can. I leave it to you. And if you can find out anything about the others, so much the better. I'll see you as soon as you finish."

It was rather a large contract. If the story had reached the newspaper stage, I should have known how to go about it. For there is no detective agency in the world like the Star, and even on the slender basis that we had, with a flock of reporters deployed at every point in the city, with telephones, wires, and cables busily engaged, I might have gathered priceless information in a few hours. But, as it was, whatever was to be got must be got by me alone.

I found Teresa de Leon registered at the Pan-America, as Craig had surmised. Such inquiries as I was able to make about the hotel did not show a trace of reason for believing that Jose Barrios had been numbered among her visitors. While that proved nothing as to the relations of the two, it was at least reassuring as far as Anitra and Eulalie were concerned, and, after all, as in such cases, this was their story.

Not having been able to learn much about the lady, I decided finally to send up my card, and to my satisfaction she sent back word that she would receive me in the parlor of the hotel.

Teresa de Leon proved to be a really striking type of Latin- American beauty. She was no longer young, but there was an elusiveness about her personality that made a more fascinating study than youth. I felt that with such a woman directness might be more of a surprise than subtlety.

"I suppose you know that Senor Barrios is very seriously ill?" I ventured, in answer to her inquiring gaze that played from my card to my face.

For a fleeting instant she looked startled. Yet she betrayed nothing as to whether it was fear or surprise.

"I have called his office several times," she replied, "but no one answered. Even Senor Sandoval was not there."

I felt that she was countering as cleverly as I might lead. "Then you know Mr. Sandoval also?" I asked, adding, "and Mr. Page?"

"I have known Senor Barrios a long time in Cuba," she answered, "and the others, too—here."

There was something evasive about her answers. She was trying to say neither too much nor too little. She left one in doubt whether she was trying to shield herself or to involve another. Though we chatted several minutes, I could gain nothing that would lead me to judge how intimately she knew Barrios. Except that she knew Sandoval and Page, her conversation might have been a replica of the letters we had discovered. Even when she hinted politely, but finally, that the talk was over she left me in doubt even whether she was an adventuress. The woman was an enigma. Had revenge or jealousy brought her to New York, or was she merely a tool in the hands of another?

I was not ready to return to Kennedy merely with another unanswered question, and I determined to stop again at the hotel where Barrios and his sister lived, in the hope of picking up something there.

The clerk at the desk told me that no one had called since we had been there, adding: "Except the tall gentleman, who came back. I think Senorita Barrios came down and met him in the tea-room."

Wondering whether it was Page or Sandoval the clerk meant, I sauntered down the corridor past the door of the tea-room. It was Page with whom Anitra was talking. There was no way in which I could hear what was said, although Page was very earnest and Anitra showed plainly that she was anxious to return to the sick- room up-stairs.

As I watched, I took good care that I should not be seen. It was well that I did, for once when I looked about I saw that some one else in another doorway was watching them, too, so intently that he did not see me. It was Sandoval. Jealousy of Page was written in every line of his face.

Studying the three, while I could not escape the rivalry of the two men, I was unable to see now or recollect anything that had happened which would convey even an inkling of her feelings toward them. Yet I was convinced that that way lay a problem quite as important as relations between the other triangle of Eulalie, Teresa, and Barrios. I was not psychologist enough to deal with either triangle. There was something that distinctly called for the higher mathematics of Kennedy.

Determined not to return to him entirely empty-mouthed, I thought it would be a good opportunity to see Eulalie alone, and hurried to the elevator, which whisked me up to the Barrios apartment.

Doctor Scott had not left his patient, though he seemed to realize that Eulalie was a most efficient nurse.

"No change," whispered the doctor, "except that he is reaching a crisis."

Interested as I was in the patient, it had been for the purpose of seeing Eulalie that I had come, and I was glad when Doctor Scott left us a moment.

"Has Mr. Kennedy found out anything yet?" she asked, in a tremulous whisper.

"I think he is on the right track now," I encouraged. "Has anything happened here? Remember—it is quite as important that you should tell him all as it is for him to tell you."

She looked at me a moment, then drew from a fold of her waist a yellow paper. It was a telegram. I took it and read:

Beware of Teresa de Leon, Hotel Pan-America.

A FRIEND.

"You know her?" I asked, folding the telegram, but not returning it.

Eulalie looked at me frankly and shook her head. "I have no idea who she is."

"Or of who sent the telegram?"

"None at all."

"When did you receive it?"

"Only a few minutes ago."

Here was another mystery. Who had sent the anonymous telegram to Eulalie so soon after it had been evident that Kennedy had entered the case? What was its purpose?

"I may keep this?" I asked, indicating the telegram.

"I was about to send it to Professor Kennedy," she replied. "Oh, I hope he will find something Won't you go to him and tell him to hurry?"

I needed no urging, not only for her sake, but also because I did not wish to be seen or to have the receipt of the telegram by Kennedy known so soon.

In the hotel I stopped only long enough to see that Anitra was now hurrying toward the elevator, eager to get back to her brother and oblivious to every one around. What had become of Page and the sinister watcher whom he had not seen I did not know, nor did I have time to find out.

A few moments later I rejoined Kennedy at the laboratory. He was still immersed in work, and, scarcely stopping, nodded to me to tell what I had discovered. He listened with interest until I came to the receipt of the anonymous telegram.

"Did you get it?" he asked, eagerly.

He almost seized it from my hands as I pulled it out of my pocket and studied it intently.

"Strange," he muttered. "Any of them might have sent it."

"Have you discovered anything?" I asked, for I had been watching him, consumed by curiosity, as I told my story. "Do you know yet how the thing was done?"

"I think I do," he replied, abstractedly.

"How was it?" I prompted, for his mind was now on the telegram.

"A poison-gas pistol," he resumed, coming back to the work he had just been doing. "Instead of bullets, this pistol used cartridges charged with some deadly powder. It might have been something like the anesthetic pistol devised by the police authorities in Paris some years ago when the motor bandits were operating."

"But who could have used it?" I asked.

Kennedy did not answer directly. Either he was not quite sure yet or did not feel that the time was ripe to hazard a theory. "In this case," he continued, after a moment's thought, "I shouldn't be surprised if even the wielder of the pistol probably wore a mask, doubly effective, for disguise and to protect the wielder from the fumes that were to overcome the victim."

"You have no idea who it was?" I reiterated.

Before Kennedy could answer there came a violent ring at the laboratory bell, and I hurried to the door. It was one of the bell-boys from the hotel where the Barrioses had their apartment, with a message for Kennedy.

Craig tore it open and read it hurriedly. "From Doctor Scott," he said, briefly, in answer to my anxious query. "Barrios is dead."

Even though I had been prepared for the news by my last visit, death came as a shock, as it always does. I had felt all along that Kennedy had been called in too late to do anything to save Barrios, but I had been hoping against hope. But I knew that it was not too late to catch the criminal who had done the dastardly, heartless deed. A few hours and perhaps all clues might have been covered up. But there is always something that goes wrong with crime, always some point where murder cannot be covered up. I think if people could only be got to realize it, as my experience both on the Star and with Kennedy have impressed it on me, murder would become a lost art.

Without another word Kennedy seized his hat and together we hurried to the hotel.

We found Anitra crying softly to herself, while near her sat Eulalie, tearless, stunned by the blow, broken-hearted. In the realization of the tragedy everything had been forgotten, even the mysterious anonymous telegram signed, Judas-like, "A Friend."

Sandoval, we learned, had been there when the end came, and had now gone out to make what arrangements were necessary. I had nothing against the man, but I could not help feeling that, now that the business was all Anitra's, might he not be the one to profit most by the death? The fact was that Kennedy had expressed so little opinion on the case so far that I might be pardoned for suspecting any one—even Teresa de Leon, who must have seen Jose slipping away from her in spite of her pursuit, whatever actuated it.

It was while I was in the midst of these fruitless speculations that Doctor Scott beckoned us outside, and we withdrew quietly.

"I don't know that there is anything more that I can do," he remarked, "but I promised Senor Sandoval that I would stay here until he came back. He begged me to, seems scarcely to know how to do enough to comfort his sister and Senorita Barrios."

I listened to the doctor keenly. Was it possible that Sandoval had one of those Jekyll-Hyde natures which seem to be so common in some of us? Had his better nature yielded to his worse? To my mind that has often been an explanation of crime, never an adequate defense.

Kennedy was about to say something when the elevator door down the hall opened. I expected that it was Sandoval returning, but it was Burton Page.

"They told me you were here," he said, greeting us. "I have been looking all over for you, down at your laboratory and at your apartment. Would you mind stepping down around the bend in the hall?"

We excused ourselves from Doctor Scott, wondering what Page had to reveal.

"I knew Sandoval had not returned," he began as soon as we were out of ear-shot of the doctor, "and I don't want to see him— again—not after what happened this afternoon. The man is crazy." We had reached an alcove and sank down into a soft settee.

"Why, what was that?" I asked, recalling the look of hate on the man's face as he had watched Page talking to Anitra in the tea- room.

"I'm giving you this for what it may be worth," began Page, turning from me to Kennedy. "Down in the lobby this afternoon, after you had been gone some time, I happened to run into Sandoval. He almost seized hold of me. 'You have been at the office,' he said. 'You've been rummaging around there.' Well, I denied it flatly. 'Who took those letters?' he shot back at me. All I could do was to look at him. 'I don't know about any letters. What letters?' I asked. Oh, he's a queer fellow all right. I thought he was going to kill me by the black look he gave me. He cooled down a bit, but I didn't wait for any apology. The best thing to do with these hot-headed people is to cut out and let them alone."

"How do you account for his strange actions?" asked Kennedy. "Have you ever heard anything more that he did?"

Page shrugged his shoulders as if in doubt whether to say anything, then decided quickly. "The other day I heard Barrios and Sandoval in the office. They were quite excited. Barrios was talking loudly. I didn't know at first what it was all about. But I soon found out. Sandoval had gone to him, as the head of the family, following their custom, I believe, to ask whether he might seek to win Anitra."

"Have you ever heard of Teresa de Leon?" interrupted Kennedy suddenly.

Page looked at him and hesitated. "There's some scandal, there, I'm afraid," he nodded, combining his answers. "I heard Sandoval say something about her to Barrios that day—warn him against something. That was when the argument was heated. It seemed to make Barrios angry. Sandoval said something about Barrios refusing to let him court Anitra while at the same time Barrios was engaged to Eulalie. Barrios retorted that the cases were different. He said he had decided that Anitra was going to marry an American millionaire."

There could be no doubt about how Page himself interpreted the remark. It was evident that he took it to mean himself.

"Sandoval had warned against this De Leon?" asked Kennedy, evidently having in mind the anonymous telegram.

"Something—I don't know what it was all about," returned Page, then added, in a burst of confidence: "I never heard of the lady until she came to New York and introduced herself to me. For a time she was interesting. But I'm too old for that sort of thing. Besides, she always impressed me as though she had some ulterior motive, as though she was trying to get at something through me. I cut it all out."

Kennedy nodded, but for a moment said nothing.

"I think I'll be getting out," remarked Page, with a half smile. "I don't want a knife in the back. I thought you ought to know all this, though. And if I hear anything else I'll let you know."

Kennedy thanked him and together we rode down in the next elevator, parting with Page at the hotel entrance.

It was still early in the evening, and Kennedy had no intention now of wasting a moment. He beckoned for a cab and directed the man to drive immediately to the Pan-America.

This time Teresa de Leon was plainly prepared for a visit, though I am not sure that she was prepared to receive two visitors.

"I believe you were acquainted with Senior Barrios, who died to- night?" opened Kennedy, after I had introduced him.

"He was acquainted with me," she corrected, with a purr in her voice that suggested claws.

"You were not married to him," shot out Kennedy; then before she could reply, "nor even engaged."

"He had known me a long time. We were intimate—"

"Friends," interrupted Kennedy, leaving no doubt as to the meaning of his emphasis.

She colored. It was evident that, at least to her, it was more than friendship.

"Senor Sandoval says," romanced Kennedy, in true detective style, "that you wrote—"

It was her turn to interrupt. "If Senor Sandoval says anything against me, he tells what is not—the truth."

In spite of Kennedy's grilling she was still mistress of herself.

"You introduced yourself to Burton Page, and—"

"You had better remember your own proverb," she retorted. "Don't believe anything you hear and only half you see."

Kennedy snapped down the yellow telegram before her. It was a dramatic moment. The woman did not flinch at the anonymous implication. Straight into Kennedy's eyes she shot a penetrating glance.

"Watch both of THEM," she replied, shortly, then turned and deliberately swept out of the hotel parlor as though daring us to go as far as we cared.

"I think we have started forces working for us," remarked Kennedy, coolly consulting his watch. "For the present at least let us retire to the laboratory. Some one will make a move. My game is to play one against the other—until the real one breaks."

We had scarcely switched on the lights and Kennedy was checking over the results he had obtained during his afternoon's investigations, when the door was flung open and a man dashed in on us unexpectedly. It was Sandoval, and as he advanced furiously at Kennedy I more than feared that Page's idea was correct.

"It was you, Kennedy," he hissed, "who took those letters from Jose's desk. It is you—or Page back of you—who are trying to connect me with that woman, De Leon. But let me tell you—"

A sharp click back of Sandoval caused him to cut short the remark and look about apprehensively. Kennedy's finger, sliding along the edge of the laboratory table, had merely found an electric button by which he could snap the lock on the door.

"We are two to one," returned Kennedy, nonchalantly. "That was nothing but the lock on the door closing. Mr. Jameson has a revolver in the top drawer of his desk over there. You will pardon me if I do a little telephoning—through the central office of the detective bureau? Some of our friends may not be overanxious to come here, and it may be necessary to compel their attendance."

Sandoval subsided into a sullen silence as Kennedy made arrangements to have Burton Page, Anitra, Eulalie, and Teresa de Leon hurried to us at once.

There was nothing for me to do but watch Sandoval as Kennedy prepared a little instrument with a scale and dial upon which rested an indicator resembling a watch hand, something like the new horizontal clocks which have only one hand to register seconds, minutes, and hours. In them, like a thermometer held sidewise, the hand moves along from zero to twenty-four. In this instrument a little needle did the same thing. Pairs of little wire-like strings ran to the instrument.

Kennedy had finished adjusting another instrument which was much like the saccharimeter, only more complicated, when the racing of an engine outside announced the arrival of the party in one of the police department cars.

Between us, Craig and I lost no time in disposing the visitors so that each was in possession of a pair of the wire-like strings, and then disdaining to explain why he had gathered them together so unceremoniously, Kennedy turned and finished adjusting the other apparatus.

"Most people regard light, so abundant, so necessary, so free as a matter of course," he remarked, contemplatively. "Not one person in ten thousand ever thinks of its mysterious nature or ever attempts to investigate it. In fact, most of us are in utter darkness as to light."

He paused, tapped the machine and went on, "This is a polarimeter —a simple polariscope—a step beyond the saccharimeter," he explained, with a nod at Sandoval. "It detects differences of structure in substances not visible in ordinary light.

"Light is polarized in several ways—by reflection, by transmission, but most commonly through what I have here, a prism of calcite, or Iceland spar, commonly called a Nicol prism. Light fully polarized consists of vibrations transverse to the direction of the ray, all in one plane. Ordinary light has transverse vibrations in all planes. Certain substances, due to their molecular structure, are transparent to vibrations in one plane, but opaque to those at right angles.

"Here we have," he explained, tapping the parts in order, "a source of light, passing in through this aperture, here a Nicol polarizer, next a liquid to be examined in a glass-capped tube; here on this other side an arrangement of quartz plates with rotary power which I will explain in a moment, next an analyzer, and finally the aperture for the eye of an observer."

Kennedy adjusted the glass tube containing the liquid which bore the substance scraped from the cartridge—he had picked up in the office of Jose. "Look through the eyepiece, Walter," he directed.

The field appeared halved. He made an adjustment and at once the field of vision appeared wholly the same tint. When he removed the tube it was dark.

"If a liquid has not what we call rotary power both halves of the double disk appear of the same tint," he explained. "If it has rotary power, the halves appear of different tints and the degree of rotation is measured by the alteration of thickness of this double quartz plate necessary to counteract it. It is, as I told Mr. Jameson early to-day, a rather abstruse subject, this of polarized light. I shall not bore you with it, but I think you will see in a moment why it is necessary, perhaps why some one who knew thought it would never be used.

"What I am getting at now is that some substances with the same chemical formula rotate polarized light to the right, are dextro- rotary, as, for instance, what is known as dextrose. Others rotate it to the left, are levo-rotary, as the substance called levose. Both of them are glucose. So there are substances which give the same chemical reactions which can only be distinguished by their being left or right rotary."

Craig took a bit of crystalline powder and dissolved it in ether. Then he added some strong sulphuric acid. The liquid turned yellow, then slowly a bright scarlet. Beside the first he repeated the operation with another similar-looking powder, with the identical result.

"Both of those," he remarked, holding up the vials, "were samples of pure veratrine, but obtained from different sources. You see the brilliant reaction—unmistakable. But it makes all the difference in the world in this case what was the source of the veratrine. It may mean the guilt or innocence of one of you."

He paused, to let the significance of his remark sink in. "Veratrine," he resumed, "is a form of hellebore, known to gardeners for its fatal effect on insects. There are white and green hellebore, Veratrum alba and Veratrum viride. It is the pure alkaloid, or rather one of them, that we have to deal with here— veratrine.

"There are various sources of veratrine. For instance, there is the veratrine that may be derived from the sabadilla seeds which grow in the West Indies and Mexico. It is used, I am informed, by the Germans in their lachrymatory and asphyxiating bombs."

The mention of the West Indies brought, like a flash, to my mind Sandoval and Senorita de Leon.

"Then, too," continued Kennedy, "there is a plant out in our own Western country, of which you may have heard, known as the death camas, very fatal to cattle when they eat it. The active principle in this is also veratrine."

I began to see what Kennedy was driving at. If it were veratrine derived from death camas it would point toward Page.

"Abderhalden, the great German physiological chemist, has discovered that substances that once get into the blood produce specific ferments. Not long ago, in a case, I showed it by the use of dialyzing membranes. But Abderhalden has found that the polariscope can show it also. And in this case only the polariscope can show what chemistry cannot show when we reach the point of testing Senor Barrios's blood—if that becomes necessary."

It was plain that Kennedy was confident. "There are other sources of drugs of the nature used in this case to asphyxiate and kill, but the active principle of all is veratrine. The point is, veratrine from what source? The sabadilla is dextro-rotary; the death camas is levo-rotary. Which is it here?"

As I tried to figure out the ramifications of the case, I could see that it was a cruel situation for one or the other of the girls. Was one of her lovers the murderer of Anitra's brother? Or was her own brother the murderer of Eulalie's lover? I looked at the faces before me, now tensely watching Kennedy, forgetful of the wire-like strings which they held in their hands. I studied Teresa de Leon intently for a while. She was still the enigma which she had been the first time I saw her.

Kennedy paused long enough to look through the eyepiece again as if to reassure himself finally that he was right. There was a tantalizing suspense as we waited for the verdict of science on this intensely human tragedy. Then he turned to the queer instrument over which the needle-hand was moving.

"Though some scientists would call this merely a sensitive form of galvanometer," he remarked, "it is, to me, more than that. It registers feelings, emotions. It has been registering your own every moment that I have been talking.

"But most of all it registers the grand passion. I might even call it a love meter. Love might seem to be a subject which could not be investigated. But even love can be attributed to electrical forces, or, perhaps better, is expressed by the generation of an electric current, as though the attraction between men and women were the giving off of electrons or radiations of one to the other. I have seen this galvanometer stationary during the ordinary meeting of men and women, yet exhibit all sorts of strange vibrations when true lovers meet."