Much as we had accomplished, we had not found Betty Blackwell. Except for her shadowing of Mrs. Ogleby, Clare Kendall had devoted her time to winning the confidence of the poor girl, Sybil Seymour, whom we had rescued from Margot's. Meanwhile, the estrangement of Carton and Margaret Ashton threw a cloud over even our success.

During the rest of the morning Craig was at work again in the laboratory. He was busily engaged in testing something through his powerful microscopes and had a large number of curious microphotographs spread out on the table. As I watched him, apparently there was nothing but the blood-stained gauze bandage which had been fastened to the face of the strange, light-haired woman, and on the stains on this bandage he was concentrating his attention. I could not imagine what he expected to discover from it.

I waited for Kennedy to speak, but he was too busy more than to notice that I had come in. I fell to thinking of that woman. And the more I thought of the fair face, the more I was puzzled by it. I felt somehow or other that I had seen it somewhere before, yet could not place it.

A second time I examined the unpublished photograph of Betty Blackwell as well as the pictures that had been published. The only conclusion that I could come to was that it could not be she, for although she was light-haired and of fair complexion, the face as I remembered it was that of a mature woman who was much larger than the slight Betty. I was sure of that.

Every time I reasoned it out I came to the same contradictory conclusion that I had seen her, and I hadn't. I gave it up, and as Kennedy seemed indisposed to enlighten me, I went for a stroll about the campus, returning as if drawn back to him by a lodestone.

About him was still the litter of test tubes, the photographs, the microscopes; and he was more absorbed in his delicate work than ever.

He looked up from his examination of a little glass slide and I could see by the crow's feet in the corners of his eyes that he was not looking so much at me as through me at a very puzzling problem.

"Walter," he remarked at length, "did you notice anything in particular about that blonde woman who dashed down the steps into the taxicab and escaped from the dope joint?"

"I should say that I did," I returned, glad to ease my mind of what had been perplexing me ever since. "I don't want to appear to be foolish, but, frankly, I thought I had seen her before, and then when I tried to place her I found that I could not recognize her at all. She seemed to be familiar, and yet when I tried to place her I could think of no one with just those features. It was a foolish impression, I suppose."

"That's exactly it," he exclaimed. "I thought at first it was just a foolish impression, too, an intuition which my later judgment rejected. But often those first impressions put you on the track of the truth. I reconsidered. You remember she had dropped that bandage from her face with the blood-stain on it. I picked it up and it occurred to me to try a little experiment with these blood-stains which might show something."

He paused a moment and fingered some of the microphotographs.

"What would you say," he went on, "if I should tell you that a pronounced blonde, with a fair complexion and thin, almost hooked, nose, was in reality a negress?"

"If it were anyone but you, Craig," I replied frankly, "I'd be tempted to call him something. But you—well, what's the answer? How do you know?"

"I wonder if you have ever heard of the Reichert blood test? Well, the Carnegie Institution has recently published an account of it. Professor Edward Reichert of the University of Pennsylvania has discovered that the blood crystals of all animals and men show characteristic differences.

"It has even been suggested that before the studies are over photographs of blood corpuscles may be used to identify criminals, almost like fingerprints. There is much that can be discovered already by the use of these hemoglobin clues. That hemoglobin, or red colouring matter of the blood, forms crystals has been known for a long time. These crystals vary in different animals, as they are studied under the polarizing microscope, both in form and molecular structure. That is of immense importance for the scientific criminologist.

"A man's blood is not like the blood of any other living creature, either fish, flesh, or fowl. Further, it is said that the blood of a woman or a man and of different individuals shows differences that will reveal themselves under certain tests. You can take blood from any number of animals and the scientists to-day can tell that it is not human blood, but the blood, say, of an animal.

"The scientists now can go further. They even hope soon to be able to tell the difference between individuals so closely that they can trace parentage by these tests. Already they can actually distinguish among the races of men, whether a certain sample of blood, by its crystals, is from a Chinaman, a Caucasian, or a negro. Each gives its own characteristic crystal. The Caucasian shows that he is more closely related to one group of primates; the negro to another. It is scientific proof of evolution.

"It is all the more wonderful, Walter, when you consider that these crystals are only 1-2250th of an inch in length and 1-9000th of an inch in width."

"How do you study them?" I asked.

"The method I employed was to take a little of the blood and add some oxalate of ammonium to it, then shake it up thoroughly with ether to free the hemoglobin from the corpuscles. I then separated the ether carefully from the rest of the blood mixture and put a few drops of it on a slide, covered them with a cover slip and sealed the edges with balsam. Gradually the crystals appear and they can be studied and photographed in the usual way—not only the shapes of the crystals, but also the relation that their angles bear to each other. So it is impossible to mistake the blood of one animal for another or of one race, like the white race, for that of another, like the black. In fact the physical characteristics by which some physicians profess to detect the presence of negro blood are held by other authorities to be valueless. But not so with this test."

"And you have discovered in this case?" I asked.

"That the blood on the bandage from the face of that woman who escaped was not the blood of a pure Caucasian. She shows traces of negro blood, in fact exactly what would have been expected of a mulatto."

It dawned on me that the woman must have been Marie, after all; at least that that was what he meant.

"But," I objected, "one look at her face was enough to show that she was not the dark-skinned Marie with her straight nose, her dark hair and other features. This woman was fair, had a nose that was almost hooked and hair that was almost flaxen. Remember the portrait parle."

"Just so—the portrait parle. That is what I am remembering. You recall Carton discovered that in some way these people found out that we were using it? What would they do? Why, they have thought out the only possible way in which to beat it, don't you see?

"Marie, Madame Margot, whatever you call her, had a beauty parlour. Oh, they are clever, these people. They reasoned it all out. What was a beauty parlour, a cosmetic surgery, for, if it could not be used to save them? They knew we had her scientific description. What was the thing to do, then? Why, change it, of course, change her!"

Kennedy was quite excited now.

"You know what Miss Kendall said of decorative surgery, there? They change noses, ears, foreheads, chins, even eyes. They put the thing up to Dr. Harris with his knives and bandages and lotions. He must work quickly. It would take all his time. So he disappeared into Margot's and stayed there. Marie also stayed there until such time as she might be able to walk out, another person entirely. Harris must have had charge of her features. The attendants in Margot's had charge of her complexion and hair—those were the things in which they specialized.

"Don't you see it all now? She could retire a few days into the dope joint next door and she would emerge literally a new woman ready to face us, even with Bertillon's portrait parle against her."

It was amazing how quickly Kennedy pieced the facts together into an explanation.

"Yes," he concluded triumphantly, "that blonde woman was our dark-skinned mulatto made over—Marie. But they can't escape the power of science, even by using science themselves. She might change her identity to our eyes, but she could not before the Reichert test and the microscope. No, the Ethiopian could not change her skin before the eye of science."

It was late in the afternoon that Kennedy received a hurried telephone call from Miss Kendall. I could tell by the scraps of conversation which I overheard that it was most important.

"That girl, Sybil Seymour, has broken down," was all he said as he turned from the instrument. "She will be here to-day with Miss Kendall. You must see Carton immediately. Tell him not to fail to be here, at the laboratory, this afternoon at three, sharp."

He was gone before I could question him further and there was nothing for me to do but to execute the commission he had laid on me.

I met Carton at his club, relating to him all that I could about the progress of the case. He seemed interested but I could see that his mind was really not on it. The estrangement between him and Margaret Ashton outweighed success in this case and even in the election.

Half an hour before the appointed time, however, we arrived at the laboratory in Carton's car, to find Kennedy already there, putting the finishing touches on the preparations he was making to receive his "guests."

"Dorgan will be here," he answered, evading Carton's question as to what he had discovered.

"Dorgan?" we repeated in surprise.

"Yes. I have made arrangements to have Martin Ogleby, too. They won't dare stay away. Ike the Dropper, Dr. Harris, and Marie Margot have not been found yet, but Miss Kendall will bring Sybil Seymour. Then we shall see."

The door opened. It was Ogleby. He bowed stiffly, but before he could say anything, a noise outside heralded the arrival of someone else.

It proved to be Dorgan, who had come from an opposite direction. Dorgan seemed to treat the whole affair with contempt, which he took pleasure in showing. He was cool and calm, master of himself, in any situation no matter how hostile.

As we waited, the strained silence, broken only by an occasional whisper between Carton and Kennedy, was relieved even by the arrival of Miss Kendall and Sybil Seymour in a cab. As they entered I fancied that a friendship had sprung up between the two, that Miss Kendall had won her fight for the girl. Indeed, I suspect that it was the first time in years that the girl had had a really disinterested friend of either sex.

I thought Ogleby visibly winced as he caught sight of Miss Seymour. He evidently had not expected her, and I thought that perhaps he had no relish for the recollection of the Montmartre which her presence suggested.

Miss Seymour, now like herself as she had appeared first behind the desk at the hotel, only subdued and serious, seemed ill at ease. Dorgan, on the other hand, bowed to her brazenly and mockingly. He was evidently preparing against any surprises which Craig might have in store, and maintained his usual surly silence.

"Perhaps," hemmed Ogleby, clearing his throat and looking at his watch ostentatiously, "Professor Kennedy can inform us regarding the purpose of this extra-legal proceeding? Some of us, I know, have other engagements. I would suggest that you begin, Professor."

He placed a sarcastic emphasis on the word "professor," as the two men faced each other—Craig tall, clean-cut, earnest; Ogleby polished, smooth, keen.

"Very well," replied Craig with that steel-trap snap of his jaws which
I knew boded ill for someone.

"It is not necessary for me to repeat what has happened at the Montmartre and the beauty parlour adjoining it," began Kennedy deliberately. "One thing, however, I want to say. Twice, now, I have seen Dr. Harris handing out packets of drugs—once to Ike the Dropper, agent for the police and a corrupt politician, and once to a mulatto woman, almost white, who conducted the beauty parlour and dope joint which I have mentioned, a friend and associate of Ike the Dropper, a constant go-between from Ike to the corrupt person higher up.

"This woman, whom I have just mentioned, we have been seeking by use of Bertillon's new system of the portrait parle. She has escaped, for the time, by a very clever ruse, by changing her very face in the beauty parlour. She is Madame Margot herself!"

Not a word was breathed by any of the little audience as they hung on
Kennedy's words.

"Why was it necessary to get Betty Blackwell out of the way?" he asked suddenly, then without waiting for an answer, "You know and District Attorney Carton knows. Someone was afraid of Carton and his crusade. Someone wanted to destroy the value of that Black Book, which I now have. The only safety lay in removing the person whose evidence would be required in court to establish it—Betty Blackwell. And the manner? What more natural than to use the dope fiends and the degenerates of the Montmartre gang?"

"That's silly," interrupted Ogleby contemptuously.

"Silly? You can say that—you, the tool of that—that monster?"

It was a woman's voice that interrupted. I turned. Sybil Seymour, her face blazing with resentment, had risen and was facing Ogleby squarely.

"You lie!" exclaimed the Silent Boss, forgetting both his silence and his superciliousness.

The situation was tense as the girl faced him.

"Go on, Sybil," urged Clare.

"Be careful, woman," cried Dorgan roughly.

Sybil Seymour turned quickly to her new assailant. "You are the man for whom we were all coined into dollars," she scorned, "Dorgan—politician, man higher up! You reaped the profits through your dirty agent, Ike the Dropper, and those over him, even the police you controlled. Dr. Harris, Marie Margot, all are your tools—and the worst of them all is this man Martin Ogleby!"

Dorgan's face was livid. For once in his life he was speechless rather than silent, as the girl poured out the inside gossip of the Montmartre which Kennedy had now stamped with the earmarks of legal proof.

She had turned from Dorgan, as if from an unclean animal and was now facing Ogleby.

"As for you, Martin Ogleby, they call you a club-man and society leader. Do you want to know what club I think you really belong to—you who have involved one girl after another in the meshes of this devilish System? You belong to the Abduction Club—that is what I would call it—you—you libertine!"