"You haven't heard—no one outside has heard—of the strange illness and the robbery of my employer, Mr. Mansfield—'Diamond Jack' Mansfield, you know."

Our visitor was a slight, very pretty, but extremely nervous girl, who had given us a card bearing the name Miss Helen Grey.

"Illness—robbery?" repeated Kennedy, at once interested and turning a quick glance at me.

I shrugged my shoulders in the negative. Neither the Star nor any of the other papers had had a word about it.

"Why, what's the trouble?" he continued to Miss Grey.

"You see," she explained, hurrying on, "I'm Mr. Mansfield's private secretary, and—oh, Professor Kennedy, I don't know, but I'm afraid it is a case for a detective rather than a doctor." She paused a moment and leaned forward nearer to us. "I think he has been poisoned!"

The words themselves were startling enough without the evident perturbation of the girl. Whatever one might think, there was no doubt that she firmly believed what she professed to fear. More than that, I fancied I detected a deeper feeling in her tone than merely loyalty to her employer.

"Diamond Jack" Mansfield was known in Wall Street as a successful promoter, on the White Way as an assiduous first-nighter, in the sporting fraternity as a keen plunger. But of all his hobbies, none had gained him more notoriety than his veritable passion for collecting diamonds.

He came by his sobriquet honestly. I remembered once having seen him, and he was, in fact, a walking De Beers mine. For his personal adornment, more than a million dollars' worth of gems did relay duty. He had scores of sets, every one of them fit for a king of diamonds. It was a curious hobby for a great, strong man, yet he was not alone in his love of and sheer affection for things beautiful. Not love of display or desire to attract notice to himself had prompted him to collect diamonds, but the mere pleasure of owning them, of associating with them. It was a hobby.

It was not strange, therefore, to suspect that Mansfield might, after all, have been the victim of some kind of attack. He went about with perfect freedom, in spite of the knowledge that crooks must have possessed about his hoard.

"What makes you think he has been poisoned?" asked Kennedy, betraying no show of doubt that Miss Grey might be right.

"Oh, it's so strange, so sudden!" she murmured.

"But how do you think it could have happened?" he persisted.

"It must have been at the little supper-party he gave at his apartment last night," she answered, thoughtfully, then added, more slowly, "and yet, it was not until this morning, eight or ten hours after the party, that he became ill." She shuddered. "Paroxysms of nausea, followed by stupor and such terrible prostration. His valet discovered him and sent for Doctor Murray—and then for me."

"How about the robbery?" prompted Kennedy, as it became evident that it was Mansfield's physical condition more than anything else that was on Miss Grey's mind.

"Oh yes"—she recalled herself—"I suppose you know something of his gems? Most people do." Kennedy nodded. "He usually keeps them in a safe-deposit vault downtown, from which he will get whatever set he feels like wearing. Last night it was the one he calls his sporting-set that he wore, by far the finest. It cost over a hundred thousand dollars, and is one of the most curious of all the studies in personal adornment that he owns. All the stones are of the purest blue-white and the set is entirely based on platinum.

"But what makes it most remarkable is that it contains the famous M-1273, as he calls it. The M stands for Mansfield, and the figures represent the number of stones he had purchased up to the time that he acquired this huge one."

"How could they have been taken, do you think?" ventured Kennedy. Miss
Grey shook her head doubtfully.

"I think the wall safe must have been opened somehow," she returned.

Kennedy mechanically wrote the number, M-1273, on a piece of paper.

"It has a weird history," she went on, observing what he had written, "and this mammoth blue-white diamond in the ring is as blue as the famous Hope diamond that has brought misfortune through half the world. This stone, they say, was pried from the mouth of a dying negro in South Africa. He had tried to smuggle it from the mine, and when he was caught cursed the gem and every one who ever should own it. One owner in Amsterdam failed; another in Antwerp committed suicide; a Russian nobleman was banished to Siberia, and another went bankrupt and lost his home and family. Now here it is in Mr. Mansfield's life. I—I hate it!" I could not tell whether it was the superstition or the recent events themselves which weighed most in her mind, but, at any rate, she resumed, somewhat bitterly, a moment later: "M-1273! M is the thirteenth letter of the alphabet, and 1, 2, 7, 3 add up to thirteen. The first and last numbers make thirteen, and John Mansfield has thirteen letters in his name. I wish he had never worn the thing—never bought it!"

The more I listened to her the more impressed I was with the fact that there was something more here than the feeling of a private secretary.

"Who were in the supper-party?" asked Kennedy.

"He gave it for Madeline Hargrave—the pretty little actress, you know, who took New York by storm last season in 'The Sport' and is booked, next week, to appear in the new show, 'The Astor Cup.'"

Miss Grey said it, I thought, with a sort of wistful envy. Mansfield's gay little bohemian gatherings were well known. Though he was not young, he was still somewhat of a Lothario.

"Who else was there?" asked Kennedy.

"Then there was Mina Leitch, a member of Miss Hargrave's new company," she went on. "Another was Fleming Lewis, the Wall Street broker. Doctor Murray and myself completed the party."

"Doctor Murray is his personal physician?" ventured Craig.

"Yes. You know when Mr. Mansfield's stomach went back on him last year it was Doctor Murray who really cured him."

Kennedy nodded.

"Might this present trouble be a recurrence of the old trouble?"

She shook her head. "No; this is entirely different. Oh, I wish that you could go with me and see him!" she pleaded.

"I will," agreed Kennedy.

A moment later we were speeding in a taxicab over to the apartment.

"Really," she remarked, nervously, "I feel lost with Mr. Mansfield so ill. He has so many interests downtown that require constant attention that just the loss of time means a great deal. Of course, I understand many of them—but, you know, a private secretary can't conduct a man's business. And just now, when I came up from the office, I couldn't believe that he was too ill to care about things until I actually saw him."

We entered the apartment. A mere glance about showed that; even though Mansfield's hobby was diamonds, he was no mean collector of other articles of beauty. In the big living-room, which was almost like a studio, we met a tall, spare, polished-mannered man, whom I quickly recognized as Doctor Murray.

"Is he any better?" blurted out Miss Grey, even before our introductions were over. Doctor Murray shook his head gravely.

"About the same," he answered, though one could find little reassurance in his tone.

"I should like to see him," hinted Kennedy, "unless there is some real reason why I should not."

"No," replied the doctor, absently; "on the contrary, it might perhaps rouse him."

He led the way down the hall, and Kennedy and I followed, while Miss Grey attempted to busy herself over some affairs at a huge mahogany table in the library just off the living-room.

Mansfield had shown the same love of luxury and the bizarre even in the furnishing of his bedroom, which was a black-and-white room with furniture of Chinese lacquer and teakwood.

Kennedy looked at the veteran plunger long and thoughtfully as he lay stretched out, listless, on the handsome bed. Mansfield seemed completely indifferent to our presence. There was something uncanny about him. Already his face was shrunken, his skin dark, and his eyes were hollow.

"What do you suppose it is?" asked Kennedy, bending over him, and then rising and averting his head so that Mansfield could not hear, even if his vagrant faculties should be attracted. "His pulse is terribly weak and his heart scarcely makes a sound."

Doctor Murray's face knit in deep lines.

"I'm afraid," he said, in a low tone, "that I will have to admit not having been able to diagnose the trouble, I was just considering whom I might call in."

"What have you done?" asked Kennedy, as the two moved a little farther out of ear-shot of the patient.

"Well," replied the doctor, slowly, "when his valet called me in, I must admit that my first impression was that I had to deal with a case of diphtheria. I was so impressed that I even took a blood smear and examined it. It showed the presence of a tox albumin. But it isn't diphtheria. The antitoxin has had no effect. No; it isn't diphtheria. But the poison is there. I might have thought it was cholera, only that seems so impossible here in New York." Doctor Murray looked at Kennedy with no effort to conceal his perplexity. "Over and over I have asked myself what it could be," he went on. "It seems to me that I have thought over about everything that is possible. Always I get back to the fact that there is that tox albumin present. In some respects, it seems like the bite of a poisonous animal. There are no marks, of course, and it seems altogether impossible, yet it acts precisely as I have seen snake bites affect people. I am that desperate that I would try the Noguchi antivenene, but it would have no more effect than the antitoxin. No; I can only conclude that there is some narcotic irritant which especially affects the lungs and heart."

"Will you let me have one of the blood smears?" asked Kennedy.

"Certainly," replied the doctor, reaching over and taking a glass slide from several lying on a table.

For some time after we left the sick-room Craig appeared to be considering what Doctor Murray had said.

Seeking to find Miss Grey in the library, we found ourselves in the handsome, all-wood-paneled dining-room. It still showed evidences of the late banquet of the night before.

Craig paused a moment in doubt which way to go, then picked up from the table a beautifully decorated menu-card. As he ran his eye down it mechanically, he paused.

"Champignons," he remarked, thoughtfully. "H-m!—mushrooms."

Instead of going on toward the library, he turned and passed through a swinging door into the kitchen. There was no one there, but it was in a much more upset condition than the dining-room.

"Pardon, monsieur," sounded a voice behind us.

It was the French chef who had entered from the direction of the servants' quarters, and was now all apologies for the untidy appearance of the realm over which he presided. The strain of the dinner had been too much for his assistants, he hastened to explain.

"I see that you had mushrooms—creamed," remarked Kennedy.

"Oui, monsieur," he replied; "some that Miss Hargrave herself sent in from her mushroom-cellar out in the country."

As he said it his eye traveled involuntarily toward a pile of ramekins on a table. Kennedy noticed it and deliberately walked over to the table. Before I knew what he was about he had scooped from them each a bit of the contents and placed it in some waxed paper that was lying near by. The chef watched him curiously.

"You would not find my kitchen like this ordinarily," he remarked. "I would not like to have Doctor Murray see it, for since last year, when monsieur had the bad stomach, I have been very careful."

The chef seemed to be nervous.

"You prepared the mushrooms yourself?" asked Kennedy, suddenly.

"I directed my assistant," came back the wary reply.

"But you know good mushrooms when you see them?"

"Certainly," he replied, quickly.

"There was no one else in the kitchen while you prepared them?"

"Yes," he answered, hurriedly; "Mr. Mansfield came in, and Miss Hargrave. Oh, they are very particular! And Doctor Murray, he has given me special orders ever since last year, when monsieur had the bad stomach," he repeated.

"Was any one else here?"

"Yes—I think so. You see, I am so excited—a big dinner—such epicures—everything must be just so—I cannot say."

There seemed to be little satisfaction in quizzing the chef, and Kennedy turned again into the dining-room, making his way back to the library, where Miss Grey was waiting anxiously for us.

"What do you think?" she asked, eagerly.

"I don't know what to think," replied Kennedy. "No one else has felt any ill effects from the supper, I suppose?"

"No," she replied; "at least, I'm sure I would have heard by this time if they had."

"Do you recall anything peculiar about the mushrooms?" shot out Kennedy.

"We talked about them some time, I remember," she said, slowly. "Growing mushrooms is one of Miss Hargrave's hobbies out at her place on Long Island."

"Yes," persisted Kennedy; "but I mean anything peculiar about the preparation of them."

"Why, yes," she said, suddenly; "I believe that Miss Hargrave was to have superintended them herself. We all went out into the kitchen. But it was too late. They had been prepared already."

"You were all in the kitchen?"

"Yes; I remember. It was before the supper and just after we came in from the theater-party which Mr. Mansfield gave. You know Mr. Mansfield is always doing unconventional things like that. If he took a notion, he would go into the kitchen of the Ritz."

"That is what I was trying to get out of the chef—Francois," remarked Kennedy. "He didn't seem to have a very clear idea of what happened. I think I'll see him again—right away."

We found the chef busily at work, now, cleaning up. As Kennedy asked him a few inconsequential questions, his eye caught a row of books on a shelf. It was a most complete library of the culinary arts. Craig selected one and turned the pages over rapidly. Then he came back to the frontispiece, which showed a model dinner-table set for a number of guests. He placed the picture before Francois, then withdrew it in, I should say, about ten seconds. It was a strange and incomprehensible action, but I was more surprised when Kennedy added:

"Now tell me what you saw."

Francois was quite overwhelming in his desire to please. Just what was going on in his mind I could not guess, nor did he betray it, but quickly he enumerated the objects on the table, gradually slowing up as the number which he recollected became exhausted.

"Were there candles?" prompted Craig, as the flow of Francois's description ceased.

"Oh yes, candles," he agreed, eagerly.

"Favors at each place?"

"Yes, sir."

I could see no sense in the proceeding, yet knew Kennedy too well to suppose, for an instant, that he had not some purpose.

The questioning over, Kennedy withdrew, leaving poor Francois more mystified than ever.

"Well," I exclaimed, as we passed through the dining-room, "what was all that?"

"That," he explained, "is what is known to criminologists as the 'Aussage test.' Just try it some time when you get a chance. If there are, say, fifty objects in a picture, normally a person may recall perhaps twenty of them."

"I see," I interrupted; "a test of memory."

"More than that," he replied. "You remember that, at the end, I suggested several things likely to be on the table. They were not there, as you might have seen if you had had the picture before you. That was a test of the susceptibility to suggestion of the chef. Francois may not mean to lie, but I'm afraid we'll have to get along without him in getting to the bottom of the case. You see, before we go any further we know that he is unreliable—to say the least. It may be that nothing at all happened in the kitchen to the mushrooms. We'll never discover it from him. We must get it elsewhere."

Miss Grey had been trying to straighten out some of the snarls which Mansfield's business affairs had got into as a result of his illness; but it was evident that she had difficulty in keeping her mind on her work.

"The next thing I'd like to see," asked Kennedy, when we rejoined her, "is that wall safe." She led the way down the hall and into an ante-room to Mansfield's part of the suite. The safe itself was a comparatively simple affair inside a closet. Indeed, I doubt whether it had been seriously designed to be burglar-proof. Rather it was merely a protection against fire.

"Have you any suspicion about when the robbery took place?" asked Kennedy, as we peered into the empty compartment. "I wish I had been called in the first thing when it was discovered. There might have been some chance to discover fingerprints. But now, I suppose, every clue of that sort has been obliterated."

"No," she replied; "I don't know whether it happened before or after
Mr. Mansfield was discovered so ill by his valet."

"But at least you can give me some idea of when the jewels were placed in the safe."

"It must have been before the supper, right after our return from the theater."

"So?" considered Kennedy. "Then that would mean that they might have been taken by any one, don't you see? Why did he place them in the safe so soon, instead of wearing them the rest of the evening?"

"I hadn't thought of that way of looking at it," she admitted. "Why, when we came home from the theater I remember it had been so warm that Mr. Mansfield's collar was wilted and his dress shirt rumpled. He excused himself, and when he returned he was not wearing the diamonds. We noticed it, and Miss Hargrave expressed a wish that she might wear the big diamond at the opening night of 'The Astor Cup.' Mr. Mansfield promised that she might and nothing more was said about it."

"Did you notice anything else at the dinner—no matter how trivial?" asked Kennedy.

Helen Grey seemed to hesitate, then said, in a low voice, as though the words were wrung from her:

"Of course, the party and the supper were given ostensibly to Miss Hargrave. But—lately—I have thought he was paying quite as much attention to Mina Leitch."

It was quite in keeping with what we knew of "Diamond Jack." Perhaps it was this seeming fickleness which had saved him from many entangling alliances. Miss Grey said it in such a way that it seemed like an apology for a fault in his character which she would rather have hidden. I could not but fancy that it mitigated somewhat the wistful envy I had noticed before when she spoke of Madeline Hargrave.

While he had been questioning her Kennedy had been examining the wall safe, particularly with reference to its accessibility from the rest of the apartment. There appeared to be no reason why one could not have got at it from the hallway as well as from Mansfield's room.

The safe itself seemed to yield no clue, and Kennedy was about to turn away when he happened to glance down at the dark interior of the closet floor. He stooped down. When he rose he had something in his hand. It was just a little thin piece of something that glittered iridescently.

"A spangle from a sequin dress," he muttered to himself; then, turning to Miss Grey, "Did any one wear such a dress last night?"

Helen Grey looked positively frightened. "Miss Hargrave!" she murmured, simply. "Oh, it cannot be—there must be some mistake!"

Just then we heard voices in the hall.

"But, Murray, I don't see why I can't see him," said one.

"What good will it do, Lewis?" returned the other, which I recognized as that of Doctor Murray.

"Fleming Lewis," whispered Miss Grey, taking a step out into the hallway.

A moment later Doctor Murray and Lewis had joined us.

I could see that there was some feeling between the two men, though what it was about I could not say. As Miss Grey introduced us, I glanced hastily out of the corner of my eye at Kennedy. Involuntarily his hand which held the telltale sequin had sought his waistcoat pocket, as though to hide it. Then I saw him check the action and deliberately examine the piece of tinsel between his thumb and forefinger.

Doctor Murray saw it, too, and his eyes were riveted on it, as though instantly he saw its significance.

"What do you think—Jack as sick as a dog, and robbed, too, and yet Murray says I oughtn't to see him!" complained Lewis, for the moment oblivious to the fact that all our eyes were riveted on the spangle between Kennedy's fingers. And then, slowly it seemed to dawn on him what it was. "Madeline's!" he exclaimed, quickly. "So Mina did tear it, after all, when she stepped on the train."

Kennedy watched the faces before us keenly. No one said anything. It was evident that some such incident had happened. But had Lewis, with a quick flash of genius, sought to cover up something, protect somebody?

Miss Grey was evidently anxious to transfer the scene at least to the living-room, away from the sick-room, and Kennedy, seeing it, fell in with the idea.

"Looks to me as though this robbery was an inside affair," remarked Lewis, as we all stood for a moment in the living-room. "Do you suppose one of the servants could have been 'planted' for the purpose of pulling it off?"

The idea was plausible enough. Yet, plausible as the suggestion might seem, it took no account of the other circumstances of the case. I could not believe that the illness of Mansfield was merely an unfortunate coincidence.

Fleming Lewis's unguarded and blunt tendency to blurt out whatever seemed uppermost in his mind soon became a study to me as we talked together in the living-room. I could not quite make out whether it was studied and astute or whether it was merely the natural exuberance of youth. There was certainly some sort of enmity between him and the doctor, which the remark about the spangle seemed to fan into a flame.

Miss Grey manoeuvered tactfully, however, to prevent a scene. And, after an interchange of remarks that threw more heat than light on the matter, Kennedy and I followed Lewis out to the elevator, with a parting promise to keep in touch with Miss Grey.

"What do you think of the spangle?" I queried of Craig as Lewis bade us a hasty good-by and climbed into his car at the street-entrance. "Is it a clue or a stall?"

"That remains to be seen," he replied, noncommittally. "Just now the thing that interests me most is what I can accomplish at the laboratory in the way of finding out what is the matter with Mansfield."

While Kennedy was busy with the various solutions which he made of the contents of the ramekins that had held the mushrooms, I wandered over to the university library and waded through several volumes on fungi without learning anything of value. Finally, knowing that Kennedy would probably be busy for some time, and that all I should get for my pains by questioning him would be monosyllabic grunts until he was quite convinced that he was on the trail of something, I determined to run into the up-town office of the Star and talk over the affair as well as I could without violating what I felt had been given us in confidence.

I could not, it turned out, have done anything better, for it seemed to be the gossip of the Broadway cafes and cabarets that Mansfield had been plunging rather deeply lately and had talked many of his acquaintances into joining him in a pool, either outright or on margins. It seemed to be a safe bet that not only Lewis and Doctor Murray had joined him, but that Madeline Hargrave and Mina Leitch, who had had a successful season and some spare thousands to invest, might have gone in, too. So far the fortunes of the stock-market had not smiled on Mansfield's schemes, and, I reflected, it was not impossible that what might be merely an incident to a man like Mansfield could be very serious to the rest of them.

It was the middle of the afternoon when I returned to the laboratory with my slender budget of news. Craig was quite interested in what I had to say, even pausing for a few moments in his work to listen.

In several cages I saw that he had a number of little guinea-pigs. One of them was plainly in distress, and Kennedy had been watching him intently.

"It's strange," he remarked. "I had samples of material from six ramekins. Five of them seem to have had no effect whatever. But if the bit that I gave this fellow causes such distress, what would a larger quantity do?"

"Then one of the ramekins was poisoned?" I questioned.

"I have discovered in it, as well as in the blood smear, the tox albumin that Doctor Murray mentioned," he said, simply, pulling out his watch. "It isn't late. I think I shall have to take a trip out to Miss Hargrave's. We ought to do it in an hour and a half in a car."

Kennedy said very little as we sped out over the Long Island roads that led to the little colony of actors and actresses at Cedar Grove. He seemed rather to be enjoying the chance to get away from the city and turn over in his mind the various problems which the case presented.

As for myself, I had by this time convinced myself that, somehow, the mushrooms were involved. What Kennedy expected to find I could not guess. But from what I had read I surmised that it must be that one of the poisonous varieties had somehow got mixed with the others, one of the Amanitas, just as deadly as the venom of the rattler or the copperhead. I knew that, in some cases, Amanitas had been used to commit crimes. Was this such a case?

We had no trouble in finding the estate of Miss Hargrave, and she was at home.

Kennedy lost no time introducing himself and coming to the point of his visit. Madeline Hargrave was a slender, willowy type of girl, pronouncedly blond, striking, precisely the type I should have imagined that Mansfield would have been proud to be seen with.

"I've just heard of Mr. Mansfield's illness," she said, anxiously. "Mr.
Lewis called me up and told me. I don't see why Miss Grey or Doctor
Murray didn't let me know sooner."

She said it with an air of vexation, as though she felt slighted. In spite of her evident anxiety to know about the tragedy, however, I did not detect the depth of feeling that Helen Grey had shown. In fact, the thoughtfulness of Fleming Lewis almost led me to believe that it was he, rather than Mansfield, for whom she really cared.

We chatted a few minutes, as Kennedy told what little we had discovered. He said nothing about the spangle.

"By the way," remarked Craig, at length, "I would very much like to have a look at that famous mushroom-cellar of yours."

For the first time she seemed momentarily to lose her poise.

"I've always had a great interest in mushrooms," she explained, hastily. "You—you do not think it could be the mushrooms—that have caused Mr. Mansfield's illness, do you?"

Kennedy passed off the remark as best he could under the circumstances. Though she was not satisfied with his answer, she could not very well refuse his request, and a few minutes later we were down in the dark dampness of the cellar back of the house, where Kennedy set to work on a most exhaustive search.

I could see by the expression on his face, as his search progressed, that he was not finding what he had expected. Clearly, the fungi before us were the common edible mushrooms. The upper side of each, as he examined it, was white, with brownish fibrils, or scales. Underneath, some were a beautiful salmon-pink, changing gradually to almost black in the older specimens. The stem was colored like the top. But search as he might for what I knew he was after, in none did he find anything but a small or more often no swelling at the base, and no "cup," as it is called.

As he rose after his thorough search, I saw that he was completely baffled.

"I hardly thought you'd find anything," Miss Hargrave remarked, noticing the look on his face. "I've always been very careful of my mushrooms."

"You have certainly succeeded admirably," he complimented.

"I hope you will let me know how Mr. Mansfield is," she said, as we started back toward our car on the road. "I can't tell you how I feel. To think that, after a party which he gave for me, he should be taken ill, and not only that but be robbed at the same time! Really, you must let me know—or I shall have to come up to the city."

It seemed gratuitous for Kennedy to promise, for I knew that he was by no means through with her yet; but she thanked him, and we turned back toward town.

"Well," I remarked, as we reeled off the miles quickly, "I must say that that puts me all at sea again. I had convinced myself that it was a case of mushroom poisoning. What can you do now?"

"Do?" he echoed. "Why, go on. This puts us a step nearer the truth, that's all."

Far from being discouraged at what had seemed to me to be a fatal blow to the theory, he now seemed to be actually encouraged. Back in the city, he lost no time in getting to the laboratory again.

A package from the botanical department of the university was waiting there for Kennedy, but before he could open it the telephone buzzed furiously.

I could gather from Kennedy's words that it was Helen Grey.

"I shall be over immediately," he promised, as he hung up the receiver and turned to me. "Mansfield is much worse. While I get together some material I must take over there, Walter, I want you to call up Miss Hargrave and tell her to start for the city right away—meet us at Mansfield's. Then get Mina Leitch and Lewis. You'll find their numbers in the book—or else you'll have to get them from Miss Grey."

While I was delivering the messages as diplomatically as possible Kennedy had taken a vial from a medicine-chest, and then from a cabinet a machine which seemed to consist of a number of collars and belts fastened to black cylinders from which ran tubes. An upright roll of ruled paper supported by a clockwork arrangement for revolving it, and a standard bearing a recording pen, completed the outfit.

"I should much have preferred not being hurried," he confessed, as we dashed over in the car to Mansfield's again, bearing the several packages. "I wanted to have a chance to interview Mina Leitch alone. However, it has now become a matter of life or death."

Miss Grey was pale and worn as she met us in the living-room.

"He's had a sinking-spell," she said, tremulously. "Doctor Murray managed to bring him around, but he seems so much weaker after it. Another might—" She broke off, unable to finish.

A glance at Mansfield was enough to convince any one that unless something was done soon the end was not far.

"Another convulsion and sinking-spell is about all he can stand," remarked Doctor Murray.

"May I try something?" asked Kennedy, hardly waiting for the doctor to agree before he had pulled out the little vial which I had seen him place in his pocket.

Deftly Kennedy injected some of the contents into Mansfield's side, then stood anxiously watching the effect. The minutes lengthened. At least he seemed to be growing no worse.

In the next room, on a table, Kennedy was now busy setting out the scroll of ruled paper and its clockwork arrangement, and connecting the various tubes from the black cylinders in such a way that the recording pen just barely touched on the scroll.

He had come back to note the still unchanged condition of the patient when the door opened and a handsome woman in the early thirties entered, followed by Helen Grey. It was Mina Leitch.

"Oh, isn't it terrible! I can hardly believe it!" she cried, paying no attention to us as she moved over to Doctor Murray.

I recalled what Miss Grey had said about Mansfield's attentions. It was evident that, as far as Mina was concerned, her own attentions were monopolized by the polished physician. His manner in greeting her told me that Doctor Murray appreciated it. Just then Fleming Lewis bustled in.

"I thought Miss Hargrave was here," he said, abruptly, looking about.
"They told me over the wire she would be."

"She should be here any moment," returned Kennedy, looking at his watch and finding that considerably over an hour had elapsed since I had telephoned.

What it was I could not say, but there was a coldness toward Lewis that amounted to more than latent hostility. He tried to appear at ease, but it was a decided effort. There was no mistaking his relief when the tension was broken by the arrival of Madeline Hargrave.

The circumstances were so strange that none of them seemed to object while Kennedy began to explain, briefly, that, as nearly as he could determine, the illness of Mansfield might be due to something eaten at the supper. As he attached the bands about the necks and waists of one after another of the guests, bringing the little black cylinders thus close to the middle of their chests, he contrived to convey the impression that he would like to determine whether any one else had been affected in a lesser degree.

I watched most intently the two women who had just come in. One would certainly not have detected from their greeting and outward manner anything more than that they were well acquainted. But they were an interesting study, two quite opposite types. Madeline, with her baby-blue eyes, was of the type that craved admiration. Mina's black eyes flashed now and then imperiously, as though she sought to compel what the other sought to win.

As for Fleming Lewis, I could not fail to notice that he was most attentive to Madeline, though he watched, furtively, but none the less keenly, every movement and word of Mina.

His preparations completed, Kennedy opened the package which had been left at the laboratory just before the hasty call from Miss Grey. As he did so he disclosed several specimens of a mushroom of pale-lemon color, with a center of deep orange, the top flecked with white bits. Underneath, the gills were white and the stem had a sort of veil about it. But what interested me most, and what I was looking for, was the remains of a sort of dirty, chocolate-colored cup at the base of the stem.

"I suppose there is scarcely any need of saying," began Kennedy, "that the food which I suspect in this case is the mushrooms. Here I have some which I have fortunately been able to obtain merely to illustrate what I am going to say. This is the deadly Amanita muscaria, the fly-agaric."

Madeline Hargrave seemed to be following him with a peculiar fascination.

"This Amanita," resumed Kennedy, "has a long history, and I may say that few species are quite so interesting. Macerated in milk, it has been employed for centuries as a fly-poison, hence its name. Its deadly properties were known to the ancients, and it is justly celebrated because of its long and distinguished list of victims. Agrippina used it to poison the Emperor Claudius. Among others, the Czar Alexis of Russia died of eating it.

"I have heard that some people find it only a narcotic, and it is said that in Siberia there are actually Amanita debauchees who go on prolonged tears by eating the thing. It may be that it does not affect some people as it does others, but in most cases that beautiful gossamer veil which you see about the stem is really a shroud.

"The worst of it is," he continued, "that this Amanita somewhat resembles the royal agaric, the Amanita caesarea. It is, as you see, strikingly beautiful, and therefore all the more dangerous."

He ceased a moment, while we looked in a sort of awe at the fatally beautiful thing.

"It is not with the fungus that I am so much interested just now, however," Kennedy began again, "but with the poison. Many years ago scientists analyzed its poisonous alkaloids and found what they called bulbosine. Later it was named muscarin, and now is sometimes known as amanitin, since it is confined to the mushrooms of the Amanita genus.

"Amanitin is a wonderful and dangerous alkaloid, which is absorbed in the intestinal canal. It is extremely violent. Three to five one-thousandths of a gram, or six one-hundredths of a grain, are very dangerous. More than that, the poisoning differs from most poisons in the long time that elapses between the taking of it and the first evidences of its effects.

"Muscarin," Kennedy concluded, "has been chemically investigated more often than any other mushroom poison and a perfect antidote has been discovered. Atropin, or belladonna, is such a drug."

For a moment I looked about at the others in the room. Had it been an accident, after all? Perhaps, if any of the others had been attacked, one might have suspected that it was. But they had not been affected at all, at least apparently. Yet there could be no doubt that it was the poisonous muscarin that had affected Mansfield.

"Did you ever see anything like that?" asked Kennedy, suddenly, holding up the gilt spangle which he had found on the closet floor near the wall safe.

Though no one said a word, it was evident that they all recognized it. Lewis was watching Madeline closely. But she betrayed nothing except mild surprise at seeing the spangle from her dress. Had it been deliberately placed there, it flashed over me, in order to compromise Madeline Hargrave and divert suspicion from some one else?

I turned to Mina. Behind the defiance of her dark eyes I felt that there was something working. Kennedy must have sensed it even before I did, for he suddenly bent down over the recording needle and the ruled paper on the table.

"This," he shot out, "is a pneumograph which shows the actual intensity of the emotions by recording their effects on the heart and lungs together. The truth can literally be tapped, even where no confession can be extracted. A moment's glance at this line, traced here by each of you, can tell the expert more than words."

"Then it was a mushroom that poisoned Jack!" interrupted Lewis, suddenly. "Some poisonous Amanita got mixed with the edible mushrooms?"

Kennedy answered, quickly, without taking his eyes off the line the needle was tracing:

"No; this was a case of the deliberate use of the active principle itself, muscarin—with the expectation that the death, if the cause was ever discovered, could easily be blamed on such a mushroom. Somehow—there were many chances—the poison was slipped into the ramekin Francois was carefully preparing for Mansfield. The method does not interest me so much as the fact—"

There was a slight noise from the other room where Mansfield lay. Instantly we were all on our feet. Before any of us could reach the door Helen Grey had slipped through it.

"Just a second," commanded Kennedy, extending the sequin toward us to emphasize what he was about to say. "The poisoning and the robbery were the work of one hand. That sequin is the key that has unlocked the secret which my pneumograph has recorded. Some one saw that robbery committed—knew nothing of the contemplated poisoning to cover it. To save the reputation of the robber—at any cost—on the spur of the moment the ruse of placing the sequin in the closet occurred."

Madeline Hargrave turned to Mina, while I recalled Lewis's remark about Mina's stepping on the train and tearing it. The defiance in her black eyes flashed from Madeline to Kennedy.

"Yes," she cried; "I did it! I—"

As quickly the defiance had faded. Mina Leitch had fainted.

"Some water—quick!" cried Kennedy.

I sprang through the door into Mansfield's room. As I passed I caught sight of Helen Grey supporting the head of Mansfield—both oblivious to actresses, diamonds, everything that had so nearly caused a tragedy.

"No," I heard Kennedy say to Lewis as I returned; "it was not Mina. The
person she shielded was wildly in love with her, insanely jealous of
Mansfield for even looking at her, and in debt so hopelessly in
Mansfield's ventures that only the big diamond could save him—Doctor
Murray himself!"