She drew off her left glove, a delicate, crinkled suede affair, and offered her bare hand to the surgeon. An artist would have called it beautiful, perfect, even; the surgeon, professionally enough, set it down as an excellent structural specimen. From the polished pink nails of the tapering fingers to the firm, well moulded wrist, it was distinctly the hand of a woman of ease — one that had never known labour, a pampered hand Dr. Prescott told himself.

“The forefinger,” she explained calmly. “I should like to have it amputated at the first joint, please.”

“Amputated?” gasped Dr. Prescott. He stared into the pretty face of his caller. It was flushed softly, and the red lips were parted in a slight smile. It seemed quite an ordinary affair to her. The surgeon bent over the hand with quick interest. “Amputated!” he repeated.

“I came to you,” she went on with a nod, “because I have been informed that you are one of the most skilful men of your profession, and the cost of the operation is quite immaterial.”

Dr. Prescott pressed the pink nail of the forefinger then permitted the blood to rush back into it. Several times he did this, then he turned the hand over and scrutinized it closely inside from the delicately lined palm to the tips of the fingers. When he looked up at last there was an expression of frank bewilderment on his face.

“What’s the matter with it?” he asked.

“Nothing,” the woman replied pleasantly. “I merely want it off from the first joint.”

The surgeon leaned back in his chair with a frown of perplexity on his brow, and his visitor was subjected to a sharp, professional stare. She bore it unflinchingly and even smiled a little at his obvious perturbation.

“Why do you want it off?” he demanded.

The woman shrugged her shoulders a little impatiently.

“I can’t tell you that,” she replied. “It really is not necessary that you should know. You are a surgeon, I want an operation performed. That is all.”

There was a long pause; the mutual stare didn’t waver.

“You must understand, Miss — Miss — er —” began Dr. Prescott at last. “By the way, you have not introduced yourself?” She was silent. “May I ask your name?”

“My name is of no consequence,” she replied calmly. “I might, of course, give you a name, but it would not be mine, therefore any name would be superfluous.”

Again the surgeon stared.

“When do you want the operation performed?” he inquired.

“Now,” she replied. “I am ready.”

“You must understand,” he said severely, “that surgery is a profession for the relief of human suffering, not for mutilation — wilful mutilation I might say.”

“I understand that perfectly,” she said. “But where a person submits of her own desire to — to mutilation as you call it I can see no valid objection on your part.”

“It would be criminal to remove a finger where there is no necessity for it,” continued the surgeon bluntly. “No good end could be served.”

A trace of disappointment showed in the young woman’s face, and again she shrugged her shoulders.

“The question after all,” she said finally, “is not one of ethics but is simply whether or not you will perform the operation. Would you do it for, say, a thousand dollars?”

“Not for five thousand dollars,” blurted the surgeon,

“Well, for ten thousand then?” she asked, quiet casually.

All sorts of questions were pounding in Dr. Prescott’s mind. Why did a young and beautiful woman desire — why was she anxious even — to sacrifice a perfectly healthy finger? What possible purpose would it serve to mar a hand which was as nearly perfect as any he had ever seen? Was it some insane caprice? Staring deeply into her steady, quiet eyes he could only be convinced of her sanity. Then what?

“No, madam,” he said at last, vehemently, “I would not perform the operation for any sum you might mention, unless I was first convinced that the removal of that finger was absolutely necessary. That, I think, is all.”

He arose as if to end the consultation. The woman remained seated and continued thoughtful for a minute.

“As I understand it,” she said, “you would perform the operation if I could convince you that it was absolutely necessary?”

“Certainly,” he replied promptly, almost eagerly. His curiosity was aroused. “Then it would come well within the range of my professional duties.”

“Won’t you take my word that it is necessary, and that it is impossible for me to explain why?”

“No. I must know why.”

The woman arose and stood facing him. The disappointment had gone from her face now.

“Very well,” she remarked steadily. “You will perform the operation if it is necessary, therefore if I should shoot the finger off, perhaps —?”

“Shoot it off?” exclaimed Dr. Prescott in amazement. “Shoot it off?”

“That is what I said,” she replied calmly. “If I should shoot the finger off you would consent to dress the wound? You would make any necessary amputation?”

She held up the finger under discussion and looked at it curiously. Dr. Prescott himself stared at it with a sudden new interest.

“Shoot it off?” he repeated. “Why you must be mad to contemplate such a thing,” he exploded, and his face flushed in sheer anger. “I— I will have nothing whatever to do with the affair, madam. Good day.”

“I should have to be very careful of course,” she mused, “but I think perhaps one shot would be sufficient, then I should come to you and demand that you dress it?”

There was a question in the tone. Dr. Prescott stared at her for a full minute then walked over and opened the door.

“In my profession, madam,” he said coldly, “there is too much possibility of doing good and relieving actual suffering for me to consider this matter or discuss it further with you. There are three persons now waiting in the ante-room who need my services. I shall be compelled to ask you to excuse me.”

“But you will dress the wound?” the woman insisted, undaunted by his forbidding tone and manner.

“I shall have nothing whatever to do with it,” declared the surgeon, positively, finally. “If you need the services of any medical man permit me to suggest that it is an alienist and not a surgeon.”

The woman didn’t appear to take offence.

“Someone would have to dress it,” she continued insistently. “I should much prefer that it be a man of undisputed skill — you I mean, therefore I shall call again. Good day.”

There was a rustle of silken skirts and she was gone. Dr. Prescott stood for an instant gazing after her with frank wonder and annoyance in his eyes, his attitude, then he went back and sat down at the desk. The crinkled suede glove still lay where she had left it. He examined it gingerly then with a final shake of his head dismissed the affair and turned to other things.

Early next afternoon Dr. Prescott was sitting in his office writing when the door from the ante-room where patients awaited his leisure was thrown open and the young man in attendance rushed in.

“A lady has fainted, sir,” he said hurriedly. “She seems to be hurt.”

Dr. Prescott arose quickly and strode out. There, lying helplessly back in her chair with white face and closed eyes, was his visitor of the day before. He stepped toward her quickly then hesitated as he recalled their conversation. Finally, however, professional instinct, the desire to relieve suffering, and perhaps curiosity too, caused him to go to her. The left hand was wrapped in an improvised bandage through which there was a trickle of blood. He glared at it with incredulous eyes.

“Hanged if she didn’t do it,” he blurted angrily.

The fainting spell, Dr. Prescott saw, was due only to loss of blood and physical pain, and he busied himself trying to restore her to consciousness. Meanwhile he gave some hurried instructions to the young man who was in attendance in the ante-room.

“Call up Professor Van Dusen on the ‘phone,” he directed his assistant, “and ask him if he can assist me in a minor operation. Tell him it’s rather a curious case and I am sure it will interest him.”

It was in this manner that the problem of the superfluous finger first came to the attention of The Thinking Machine. He arrived just as the mysterious woman was opening her eyes to consciousness from the fainting spell. She stared at him glassily, unrecognizingly; then her glance wandered to Dr. Prescott. She smiled.

“I knew you’d have to do it,” she murmured weakly.

After the ether had been administered for the operation, a simple and an easy one, Dr.

Prescott stated the circumstances of the case to The Thinking Machine. The scientist stood with his long, slender fingers resting lightly on the young woman’s pulse, listening in silence.

“What do you make of it?” demanded the surgeon.

The Thinking Machine didn’t say. At the moment he was leaning over the unconscious woman squinting at her forehead. With his disengaged hand he stroked the delicately pencilled eyebrows several times the wrong way, and again at close range squinted at them. Dr. Prescott saw and seeing, understood.

“No, it isn’t that,” he said and he shuddered a little. “I thought of it myself. Her bodily condition is excellent, splendid.”

It was some time later when the young woman was sleeping lightly, placidly under the influence of a soothing potion, that The Thinking Machine spoke of the peculiar events which had preceded the operation. Then he was sitting in Dr. Prescott’s private office. He had picked up a woman’s glove from the desk.

“This is the glove she left when she first called, isn’t it?” he inquired.

“Yes.”

“Did you happen to see her remove it?”

“Yes.”

The Thinking Machine curiously examined the dainty, perfumed trifle, then, arising suddenly, went into the adjoining room where the woman lay asleep. He stood for an instant gazing down admiringly at the exquisite, slender figure; then, bending over, he looked closely at her left hand. When at last he straightened up it seemed that some unspoken question in his mind had been answered. He rejoined Dr. Prescott.

“It’s difficult to say what motive is back of her desire to have the finger amputated,” he said musingly. “I could perhaps venture a conjecture but if the matter is of no importance to you beyond mere curiosity I should not like to do so. Within a few months from now, I daresay, important developments will result and I should like to find out something more about her. That I can do when she returns to wherever she is stopping in the city. I’ll ‘phone to Mr. Hatch and have him ascertain for me where she goes, her name and other things which may throw a light on the matter.”

“He will follow her?”

“Yes, precisely. Now we only seem to know two facts in connection with her. First, she is English.”

“Yes,” Dr. Prescott agreed. “Her accent, her appearance, everything about her suggests that.”

“And the second fact is of no consequence at the moment,” resumed The Thinking Machine. “Let me use your ‘phone please.”

Hutchinson Hatch, reporter, was talking.

“When the young woman left Dr. Prescott’s she took the cab which had been ordered for her and told the driver to go ahead until she stopped him. I got a good look at her, by the way. I managed to pass just as she entered the cab and walking on down got into another cab which was waiting for me. Her cab drove for three or four blocks aimlessly, and finally stopped. The driver stooped down as if to listen to someone inside, and my cab passed. Then the other cab turned across a side street and after going eight or ten blocks pulled up in front of an apartment house. The young woman got out and went inside. Her cab went away. Inside I found out that she was Mrs. Frederick Chevedon Morey. She came there last Tuesday — this is Friday — with her husband, and they engaged —”

“Yes, I knew she had a husband,” interrupted The Thinking Machine.

“— engaged apartments for three months. When I had learned this much I remembered your instructions as to steamers from Europe landing on the day they took apartments or possibly a day or so before. I was just going out when Mrs. Morey stepped out of the elevator and preceded me to the door. She had changed her clothing and wore a different hat.

“It didn’t seem to be necessary then to find out where she was going for I knew I could find her when I wanted to, so I went down and made inquiries at the steamship offices. I found, after a great deal of work, that no one of the three steamers which arrived the day they took apartments brought a Mr. and Mrs. Morey, but one steamer on the day before brought a Mr. and Mrs. David Girardeau from Liverpool. Mrs. Girardeau answered Mrs. Morey’s description to the minutest detail even to the gown she wore when she left the steamer — that is the same she wore when she left Dr. Prescott’s after the operation.”

That was all. The Thinking Machine sat with his enormous yellow head pillowed against a high-backed chair and his long slender fingers pressed tip to tip. He asked no questions and made no comment for a long time, then:

“About how many minutes was it from the time she entered the house until she came out again?”

“Not more than ten or fifteen,” was the reply. “I was still talking casually to the people down stairs trying to find out something about them.”

“What do they pay for their apartment?” asked the scientist, irrelevantly.

“Three hundred dollars a month.”

The Thinking Machine’s squint eyes were fixed immovably on a small discoloured spot on the ceiling of his laboratory.

“Whatever else may develop in this matter, Mr. Hatch,” he said after a time, “we must admit that we have met a woman with extraordinary courage — nerve, I daresay you’d call it. When Mrs. Morey left Dr. Prescott’s operating room she was so ill and weak from the shock that she could hardly stand, and now you tell me she changed her dress and went out immediately after she returned home.”

“Well, of course —” Hatch said, apologetically.

“In that event,” resumed the scientist, “we must assume also that the matter is one of the utmost importance to her, and yet the nature of the case had led me to believe that it might be months, perhaps, before there would be any particular development in it.”

“What? How?” asked the reporter.

“The final development doesn’t seem, from what I know, to belong on this side of the ocean at all,” explained The Thinking Machine. “I imagine it is a case for Scotland Yard. The problem of course is: What made it necessary for her to get rid of that finger? If we admit her sanity we can count the possible answers to this question on one hand, and at least three of these answers take the case back to England.” He paused. “By the way, was Mrs. Morey’s hand bound up in the same way when you saw her the second time?”

“Her left hand was in a muff,” explained the reporter. “I couldn’t see but it seems to me that she wouldn’t have had time to change the manner of its dressing.”

“It’s extraordinary,” commented the scientist. He arose and paced back and forth across the room. “Extraordinary,” he repeated. “One can’t help but admire the fortitude of women under certain circumstances, Mr. Hatch. I think perhaps this particular case had better be called to the attention of Scotland Yard, but first I think it would be best for you to call on the Moreys tomorrow — you can find some pretext — and see what you can learn about them. You are an ingenious young man — I’ll leave it all to you.”

Hatch did call at the Morey apartments on the morrow but under circumstances which were not at all what he expected. He went there with Detective Mallory, and Detective Mallory went there in a cab at full speed because the manager of the apartment house had ‘phoned that Mrs. Frederick Chevedon Morey had been found murdered in her apartments. The detective ran up two flights of stairs and blundered, heavy-footed into the rooms, and there he paused in the presence of death.

The body of the woman lay on the floor and some one had mercifully covered it with a cloth from the bed. Detective Mallory drew the covering down from over the face and Hatch stared with a feeling of awe at the beautiful countenance which had, on the day before, been so radiant with life. Now it was distorted into an expression of awful agony and the limbs were drawn up convulsively. The mark of the murderer was at the white, exquisitely rounded throat — great black bruises where powerful, merciless fingers had sunk deeply into the soft flesh.

A physician in the house had preceded the police. After one glance at the woman and a swift, comprehensive look about the room Detective Mallory turned to him............