It was late in the afternoon, while Garrick was still busy with a high-powered microscope, making innumerable micro-photographs, when the door of the office opened softly and a young lady entered.

As she advanced timidly to us, we could see that she was tall and gave promise of developing with years into a stately woman—a pronounced brunette, with sparkling black eyes. I had not met her before, yet somehow I could not escape the feeling that she was familiar to me.

It was not until she spoke that I realized that it was the eyes, not the face, which I recognized.

"You are Mr. Garrick?" she asked of Guy in a soft, purring voice which, I felt, masked a woman who would fight to the end for anyone or anything she really loved.

Then, before Guy could answer, she explained, "I am Miss Violet Winslow. A friend of mine, Mr. Warrington, has told me that you are investigating a peculiar case for him—the strange loss of his car."

Garrick hastened to place a chair for her in the least cluttered and dusty part of the room. There she sat, looking up at him earnestly, a dainty contrast to the den in which Garrick was working out the capture of criminals, violent and vicious.

"I have the honor to be able to say, \'Yes\' to all that you have asked, Miss Winslow," he replied. "Is there any way in which I can be of service to you?"

I thought a smile played over his face at the thought that perhaps she might have come to ask him to work for three clients instead of two.

At any rate, the girl was very much excited and very much in earnest, as she opened her handbag and drew from it a letter which she handed to Garrick.

"I received that letter," she explained, speaking rapidly, "in the noon mail to-day. I don\'t know what to make of it. It worries me to get such a thing. What do you suppose it was sent to me for? Who could have sent it?"

She was leaning forward artlessly on her crossed knee looking expectantly up into Garrick\'s face, oblivious to everything else, even her own enticing beauty. There was something so simple and sincere about Violet Winslow that one felt instinctively that nothing was too great a price to shield her from the sordid and the evil in the world. Yet something had happened that had brought her already into the office of a detective.

Garrick had glanced quickly at the outside of the slit envelope. The postmark showed that it had been mailed early that morning at the general post office and that there was slight chance of tracing anything in that direction.

Then he opened it and read. The writing was in a bold scrawl and hastily executed:

You have heard, no doubt, of the alleged loss of an automobile by Mr. Mortimer Warrington. I have seen your name mentioned in the society columns of the newspapers in connection with him several times lately. Let a disinterested person whom you do not know warn you in time. There is more back of it than he will care to tell. I can say nothing of the nefarious uses to which that car has been put, but you will learn more shortly. Meanwhile, let me inform you that he and some of the wilder of his set had that night planned a visit to a gambling house on Forty-eighth Street. I myself saw the car standing before another gambling den on Forty-seventh Street about the same time. This place, I may as well inform you, bears an unsavory reputation as a gambling joint to which young ladies of the fastest character are admitted. If you will ask someone in whom you have confidence and whom you can ask to work secretly for you to look up the records, you will find that much of the property on these two blocks, and these two places in particular, belongs to the Warrington estate. Need I say more?

The letter was without superscription or date and was signed merely with the words, "A Well-Wisher." The innuendo of the thing was apparent.

"Of course," she remarked, as Garrick finished reading, and before he could speak, "I know there is something back of it. Some person is trying to injure Mortimer. Still—-"

She did not finish the sentence. It was evident that the "well-wisher" need not have said more in order to sow the seeds of doubt.

As I watched her narrowly, I fancied also that from her tone the newspapers had not been wholly wrong in mentioning their names together recently.

"I hadn\'t intended to say anything more than to explain how I got the letter," she went on wistfully. "I thought that perhaps you might be interested in it."

She paused and studied the toe of her dainty boot. "And, of course," she murmured, "I know that Mr. Warrington isn\'t dependent for his income on the rent that comes in from such places. But—but I wish just the same that it wasn\'t true. I tried to call him up about the letter, but he wasn\'t at the office of the Warrington estate, and no one seemed to know just where he was."

She kept her eyes downcast as though afraid to betray just what she felt.

"You will leave this with me?" asked Garrick, still scrutinizing the letter.

"Certainly," she replied. "That is what I brought it for. I thought it was only fair that he should know about it."

Garrick regarded her keenly for a moment. "I am sure, Miss Winslow," he said, "that Mr. Warrington will thank you for your frankness. More than that, I feel sure that you need have no cause to worry about the insinuations of this letter. Don\'t judge harshly until you have heard his side. There\'s a good deal of graft and vice talk flying around loose these days. Miss Winslow, you may depend on me to dig the truth out and not deceive you."

"Thank you so much," she said, as she rose to go; then, in a burst of confidence, added, "Of course, after all, I don\'t care so much about it myself—but, you know, my aunt—is so dreadfully prim and proper that she couldn\'t forgive a thing like this. She\'d never let Mr. Warrington call on me again."

Violet stopped and bit her lip. She had evidently not intended to say as much as that. But having once said it, she did not seem to wish to recall the words, either.

"There, now," she smiled, "don\'t you even hint to him that that was one of the reasons I called."

Garrick had risen and was standing beside her, looking down earnestly into her upturned face.

"I think I understand, Miss Winslow," he said in a low voice, rapidly. "I cannot tell you all—yet. But I can promise you that even if all were told—the truth, I mean—your faith in Warrington would be justified." He leaned over. "Trust me," he said simply.

As she placed her small hand in Garrick\'s, she looked up into his face, and with suppressed emotion, answered, "Thank you—I—I will."

Then, with a quick gathering of her skirts, she turned and almost fled from the room.

She had scarcely closed the door before Garrick was telephoning anxiously all over the city in order to get in touch with Warrington himself.

"I\'m not going to tell him too much about her visit," he remarked, with a pleased smile at the outcome of the interview, though his face clouded as his eye fell again on the blackmailing letter, lying before him. "It might make him think too highly of himself. Besides, I want to see, too, whether he has told us the whole truth about the affair that night."

Somehow or other it seemed impossible to find Warrington in any of his usual haunts, either at his office or at his club.

Garrick had given it up, almost, as a bad job, when, half an hour later, Warrington himself burst in on us, apparently expecting more news about his car.

Instead, Garrick handed him the letter.

"Say," he demanded as he ran through it with puckered face, then slapped it down on the table before Guy, in a high state of excitement, "what do you make of that?"

He looked from one to the other of us blankly.

"Isn\'t it bad enough to lose a car without being slandered about it into the bargain?" he asked heatedly, then adding in disgust, "And to do it in such an underhand way, writing to a girl like Violet, and never giving me a chance to square myself. If I could get my hands on that fellow," he added viciously, "I\'d qualify him for the coroner!"

Warrington had flown into a towering and quite justifiable rage. Garrick, however, ignored his anger as natural under the circumstances, and was about to ask him a question.

"Just a moment, Garrick," forestalled Warrington. "I know just what you are going to say. You are going to ask me about those gambling places. Now, Garrick, I give you my word of honor that I did not know until to-day that the property in that neighborhood was owned by our estate. I have been in that joint on Forty-eighth Street—I\'ll admit that. But, you know, I\'m no gambler. I\'ve gone simply to see the life, and—well, it has no attraction for me. Racing cars and motorboats don\'t go with poker chips and the red and black—not with me. As for the other place, I don\'t know any more about it than—than you do," he concluded vehemently.

Warrington faced Garrick, his steel-blue eye unwavering. "You see, it\'s like this," he resumed passionately, "since this vice investigation began, I have read a lot about landlords. Then, too," he interjected with a mock wry face, "I knew that Violet\'s Aunt Emma had been a crusader or something of the sort. You see, virtue is NOT its own reward. I don\'t get credit even for what I intended to do—quite the contrary."

"How\'s that?" asked Garrick, respecting the young man\'s temper.

"Why, it just occurred to me lately to go scouting around the city, looking at the Warrington holdings, making some personal inquiries as to the conditions of the leases, the character of the tenants, and the uses to which they put the properties. The police have compiled a list of all the questionable places in the city and I have compared it with the list of our properties. I hadn\'t come to this one yet. But I shall call up our agent, make him admit it, and cancel that lease. I\'ll close \'em up. I\'ll fight until every—-"

"No," interrupted Garrick, quickly, "no—not yet. Don\'t make any move yet. I want to find out what the game is. It may be that it is someone who has tried and failed to get your tenant to come across with graft money. If we act without finding out first, we might be playing into the hands of this blackmailer."

Garrick had been holding the letter in his hand, examining it critically. While he was speaking, he had taken a toothpick and was running it hastily over the words, carefully studying them. His face was wrinkled, as if he were in deep thought.

Without saying anything more, Garrick walked over to the windows and pulled down the dark shades. Then he unrolled a huge white sheet at one end of the office.

From a corner he drew out what looked like a flat-topped stand, about the height of his waist, with a curious box-like arrangement on it, in which was a powerful light. For several minutes, he occupied himself with the adjustment of this machine, switching the light off and on and focussing the lenses.

Then he took the letter to Miss Winslow, laid it flat on the machine, switched on the light and immediately on the sheet appeared a very enlarged copy of the writing.

"This is what has been called a rayograph by a detective of my acquaintance," explained Garrick. "In some ways it is much superior to using a microscope."

He was tracing over the words with a pointer, much as he had already done with the toothpick.

"Now, you must know," he continued, "or you may not know, but it is a well-proved fact, that those who suffer from various affections of the nerves or heart often betray the fact in their handwriting. Of course, in cases where the disease has progressed very far it may be evident to the naked eye even in the ordinary handwriting. But, it is there, to the eye of the expert, even in incipient cases.

"In short," he continued, engrossed in his subject, "what really happens is that the pen acts as a sort of sphygmograph, registering the pulsations. I think you can readily see that when the writing is thrown on a screen, enlarged by the rayograph, the tremors of the pen are quite apparent."

I studied the writing, following his pointer as it went over the lines and I began to understand vaguely what he was driving at.

"The writer of that blackmailing letter," continued Garrick, "as I have discovered both by hastily running over it with a tooth-pick and, more accurately, by enlarging and studying it with the rayograph, is suffering from a peculiar conjunction of nervous trouble and disease of the heart which is latent and has not yet manifested itself, even to him."

Garrick studied the writing, then added, thoughtfully, "if I knew him,
I might warn him in time."

"A fellow like that needs only the warning of a club or of a good pair of fists," growled Warrington, impatiently. "How are you going to work to find him?"

"Well," reasoned Garrick, rolling up the sheet and restoring the room to its usual condition, "for one thing, the letter makes it pretty evident that he knows something about the gambling joint, perhaps is one of the regular habitues of the place. That was why I didn\'t want you to take any steps to close up the place immediately. I want to go there and look it over while it is in operation. Now, you admit that you have been in the place, don\'t you?"

"Oh, yes," he replied, "I\'ve been there with Forbes and the other fellows, but as I told you, I don\'t go in for that sort of thing."

"Well," persisted Garrick, "you are sufficiently known, any way, to get in again."

"Certainly. I can get in again. The man at the door will let me in—and a couple of friends, too, if that\'s what you mean."

"That is exactly what I mean," returned Garrick. "It\'s no use to go early. I want to see the place in full blast, just as the after-theatre crowd is coming in. Suppose you meet us, Warrington, about half past ten or so. We can get in. They don\'t know anything yet about your intention to cancel the lease and close up the place, although apparently someone suspects it, or he wouldn\'t have been so anxious to get that letter off to Miss Winslow."

"Very well," agreed Warrington, "I will meet you at the north end of
\'Crime Square,\' as you call it, at that time. Good luck until then."

"Not a bad fellow, at all," commented Garrick when Warrington had disappeared down the hall from the office. "I believe he means to do the square thing by every one. It\'s a shame he has been dragged into a mess like this, that may affect him in ways that he doesn\'t suspect. Oh, well, there is nothing we can do for the present. I\'ll just add this clew of the handwriting to the clew of the automobile tires against the day when we get—pshaw!—he has taken the letter with him. I suppose it is safe enough in his possession, though. He can\'t wait until he has proved to Violet that he is honest. I don\'t blame him much. I told you, you know, that the younger set are just crazy over Violet Winslow."