Richard Duvall and his wife, Grace, lingered rather later than usual over their breakfast that morning.

It was a warm and brilliant day in May, and the blossoming beauty of the spring filled them both with a delightful sense of well-being.

Duvall, however, seemed a trifle restless, and Grace observed it.

"What's the matter, Richard?" she asked.

"Oh, nothing." Her husband picked up the morning paper. "They are still looking for the woman in that Marsden case, I see," he remarked.

"Do you know, my dear," Grace said, "I sometimes think that you made a mistake in coming down here to the country to live. Your heart is really in New York, and every time there is a murder case, or a bank robbery, or a kidnapping up there, you are restless as a hen on a hot griddle until the mystery is solved. Why don't you take up your professional work again?" Duvall laid down his paper and regarded his wife with a look of surprise.

"Because, Grace," he said, "you especially asked me, after that affair of the missing suffragette, to finally give up my detective work and content myself with a quiet existence here on the farm. You said, on account of the boy, that I ought not to take such risks."

"Well—suppose I did. You agreed with me, didn't you?"

"Yes—I guess so." Duvall once more picked up the newspaper. "But, naturally, I can't help feeling a certain interest in any striking and novel case that I may read about."

"And I haven't a doubt," laughed Grace, "that you wish that you were back in harness again a dozen times a day. Come now—'fess up. Don't you?"

"Sometimes," granted her husband, with a smile. "You know I loved my work. It always seemed to take me out of the dull routine of existence, and give me a new feeling of interest. I shouldn't mind if I had a novel and interesting case to work on right now."

"Would you take one, if it were offered to you?" asked Grace quickly.

"No—I guess not. I haven't forgotten my promise."

"Well—I've decided to release you from that, Richard. I really think you need a little mental exercise and diversion. All play and no work, you know——" She began to arrange the dogwood blossoms she had gathered before breakfast, in a big vase on the table.

Duvall laughed.

"I'm getting along very well," he said. "Don't forget I'm expecting to have that corner lot planted in potatoes to-day." He rose, and coming over to his wife, playfully pinched her cheek. "What's the matter, dear?" he asked. "Are you pining for a little trip to New York yourself? We don't need a murder mystery to make that possible, you know."

Grace shook her head. As she did so, the telephone bell in the hall began to ring. "That may be your murder mystery now," she said, with a laugh.

"More likely the Clarks asking us over to dinner this evening," he returned, as he made his way into the hall.

Grace continued to arrange her flowers. Presently Duvall re-entered the room. There was a curious smile upon his face. "Well," Grace remarked, glancing up. "Which was it? The murder case, or the Clarks?"

"Neither. A mysterious woman, this time, saying that she must see me at once. I told her to come on out."

"Ah! This is serious," his wife laughed. "A mysterious woman! I suppose I ought to be jealous. Didn't she say what she wanted with you?"

"No. But we'll know soon enough. She'll be here at half past nine. Suppose we go and take a look at those Airedale pups." Together they crossed the veranda and made their way toward the barn.

Richard Duvall had changed but little since the days when he had served on the staff of Monsieur Lefevre, the Prefect of Police of Paris, and had taken part in the stirring adventures of the Million Francs, the Ivory Snuff Box and the Changing Lights. The same delightful spirit of camaraderie existed between his wife, Grace, and himself, a spirit which had enabled them, together, to solve some of the most exciting mysteries in the annals of the French detective service. It had been nearly two years, now, since the affair of the Mysterious Goddess, the last case in which Duvall had been concerned, and he was beginning to feel that he would welcome with outstretched arms a chance to make use once more of his exceptional talents as an investigator of crime. Hence he had received Mrs. Morton's telephone call with more than ordinary interest.

The latter had told him nothing of her reasons for interviewing him, contenting herself with the bare statement that she had a letter to him from Mr. Stapleton. This, however, had been enough to set Duvall's nerves to tingling and to cause him to conclude that the mysterious woman who desired to interview him in such a hurry came on no ordinary business. Hence he waited with some impatience for the arrival of half past nine.

A few moments after the half hour, a large automobile swept up the drive, and Duvall, with a nod to his wife, went back to the house to receive his guest. She was waiting in the library when he entered.

"I am Mrs. Morton, of New York," his caller began, handing him Mr. Stapleton's letter.

Duvall read it, but it told him little.

"Mr. Stapleton informs me," he said, looking at his visitor, "that you are in some difficulty or other, and asks that, if I can possibly do so, I try to help you out of it. Did he not also say that I have for some time past given up the active practice of my profession?"

Mrs. Morton nodded, then bent eagerly forward.

"Yes, Mr. Duvall. He told me that. But he also said that, when you heard the circumstances, you might be persuaded to assist me. I am in very deep trouble, and I fear that there is not a moment to be lost."

"What is the nature of your difficulty, madam?" Duvall asked.

"It—it concerns my daughter. I am the mother of Ruth Morton." She made this announcement as though she fully expected Duvall to realize its significance at once, but the latter's face remained quite blank.

"Yes?" he replied, vaguely. "And who is Ruth Morton?"

Mrs. Morton looked at him in pained surprise. The thought that anyone could possibly be ignorant of her daughter's fame and success seemed unbelievable to her. Was not Ruth's name a household word among moving picture "fans" from coast to coast? "Why—Ruth Morton—the motion picture star," she replied. "Surely you must have heard of her."

Duvall smiled, but shook his head.

"I never go to motion pictures," he said. "But that is of no importance. What has happened to your daughter?"

"Nothing. At least I hope not—yet. It is what may happen to her that frightens me so." She took the two threatening letters from her handbag and gave them to the detective. "These came yesterday," she said, simply.

Duvall took the letters, and proceeded to read them with the utmost care. When he looked up, his eyes were sparkling with interest.

"The first letter, I observe," he said, "was mailed night before last, at half-past six, at the general post office. How was the other letter delivered?"

"I do not know. I found it, yesterday forenoon, upon the floor in my daughter's bedroom, an hour or more after she had left the house. She has not seen it. I kept all news of it from her, as I did not wish her to be frightened."

"That was wise, of course," Duvall said. "But how could the letter possibly have been placed where you found it, without your knowledge? Who, beside yourself, was in the apartment at the time?"

"No one but an old negro cook, who has been with me for years. I am quite certain that she had nothing to do with it."

"And the maid of whom you speak?"

"She had left my daughter's room, and come into the dining room, where I was sitting, before Ruth left the bedroom. They went out together. The note could not have been in the bedroom then, or my daughter would certainly have seen it. The thing seems almost uncanny."

Duvall began to stroke his chin, a habit with him when he was more than usually perplexed. Presently he spoke.

"One thing I have learned, Mrs. Morton, after many years spent in detective work. There is no circumstance, however mystifying it may at first appear, which is not susceptible of some reasonable and often very commonplace explanation. You find this letter on the floor in your daughter's bedroom. It was placed there, either by someone within the apartment, or by someone from without. Now you tell me that it could not have been placed from within. Then I can only say that someone must have entered the room, or at least managed to place the letter in the room, from outside."

"That may be true, Mr. Duvall," remarked Mrs. Morton, quietly, "but when you consider that our apartment is on the fourth floor, that one of the windows of the room was closed, and the other only open a few inches, and that the blank wall of the opposite house is at least ten feet away, I fail to see how what you suggest is possible."

Her words filled Duvall with surprise. If what his caller said was true, the case might have elements which would make it more than usually interesting.

"Has your daughter any enemy, who might envy her her success, and wish to deprive her of it?" he asked.

"None, that I know of. But since these two letters came, I feel convinced that someone, whom, I cannot imagine, does feel that way toward her, and that on account of it she is in the gravest danger. Don't you think so, Mr. Duvall?"

"I think it highly probable. And what, Mrs. Morton, would you like to have me do in the matter?"

"Why—come to New York, take up the case, and find out who these wretches are, so that they may be prevented from doing my daughter any harm. There is no time to lose. They may carry out their threats at any moment. You will observe that in the first letter they said that her beauty would be destroyed 'within thirty days.' One of those days has already passed. To-day is the second. At most, we have but twenty-eight days left in which to find out who is responsible for this outrage. Investigation may consume a great deal of time. I hope that you will consent to come to New York and take charge of the matter at once. I am returning this afternoon, as soon as I can get a train. Can you not return with me? As for the matter of expense, I place no limit upon it. There is nothing I would not sacrifice, to save my daughter from the fate they have threatened. Think what it would mean, Mr. Duvall. A young, beautiful, innocent girl, scarcely more than a child, to go through life with her beauty taken from her, made hideous by some fiendish device, blinded and scarred by acid, her features crushed—gashed by some sudden blow. Can you imagine anything more terrible?"

Duvall thought for moment of his own lovely child, now almost three years old, and shuddered. Bank burglaries, thefts of jewels, seemed relatively of small importance compared with such a situation as this. His feelings of chivalry rose. He felt a strong desire to help this young girl.

"Here is her picture," Mrs. Morton continued, taking a photograph from her handbag and extending it to Duvall.

The latter gazed at the charming features of the young actress, and nodded.

"She is lovely—exquisite," he murmured. "I don't wonder you feel as you do. I did not intend to take up any detective work at this time, but I have decided to assist you in this matter in any way that I can."

"Oh—thank you, Mr. Duvall." There were tears in Mrs. Morton's anxious eyes. "I can never repay you for your kindness—never. But if you can save Ruth from these scoundrels, I will gladly spend——"

"Never mind about that, Mrs. Morton," Duvall observed, with a friendly smile. "It is scarcely a question of money with me. If I had not felt a keen interest in your daughter's welfare, I should not have agreed to take up the matter at all. As it is, you need not worry about the expense. I am going to take the case largely because it has interested me, and it will be a pleasure to work it out, not only on your daughter's account, but on my own. You know, to me, such matters are of absorbing interest, like the solving of some complex and baffling puzzle."

"Then you will go back to New York with me this evening?"

"I can hardly do that, Mrs. Morton. But I can agree to call on you there to-morrow. It will take me some hours to arrange matters here so that I can leave. I do not think you need worry for a few days at least. If these people had meant to act at once they would not have named the period of thirty days in their threats."

"Very well." Mrs. Morton rose, and held out her hand. "I will expect you to-morrow. Will it be in the morning?"

"Very likely. In any event, I will first telephone to you." He entered the address in his notebook. "By the way, perhaps you had better let me keep that photograph."

"Certainly." Mrs. Morton handed it to him, and he thrust it into his pocket. "The letters you already have?"

"Yes."

"Is there anything else?"

"Yes. One thing. Do not tell your daughter that you have employed me in this case. It—it might alarm her."

"Certainly not. And that leads me to say that you, on your part, will of course observe the utmost secrecy. Even with Mrs. Duvall."

"That goes without saying, madam. My professional secrets I share with no one. Even between my wife and myself there is an unwritten law which is never broken. Unless we are working on a case together—unless she can be of service to me, she asks no questions. She would not speak to me, or even recognize me, were we to meet, while I am engaged in work of this sort. You need have no fear on that score."

"I am very glad to know that. Were these people to suspect that I have placed the matter in the hands of a detective, they would be instantly on their guard, and all means of tracing them might be lost."

"That is undoubtedly true, and for that reason, I may appear in other characters than my own, from time to time, disguised perhaps, in such a way that even you would not recognize me. Under those circumstances I will suggest a password—one that will not be known to anyone else. Should occasion arise in which I desire to acquaint you with my identity, without making it known to others, I will merely repeat the words—twenty-eight days, or twenty-seven or six or five, as the case may be, on that particular day, and you will know that it is I, and act accordingly. Is that perfectly clear?"

"Perfectly, Mr. Duvall."

"Very well. Then we will leave further details until to-morrow." He shook hands with his caller, escorted her to her automobile, then returned to the library and began a careful study of the two notes which Mrs. Morton had left with him. Here Grace found him, half an hour later.

"Well," she said, coming up to him with a smile. "Shall I begin to pack our things?"

Duvall put his arm about her.

"Yes, dear," he said. "We'll leave on the sleeper to-night. You can get Mrs. Preston to come and take charge of the house while we are gone. It may be two weeks. That is, if you want to go along."

"Want to go along? Why, Richard, I'm just dying for a trip to New York. I haven't been there since before Christmas, as you know, and I've got to get a spring outfit. Of course I'm going." She went gayly toward the hall stairs.

"Then you must be ready right after lunch," he called after her.

"But why so soon, if we are taking the sleeper?"

"Because we are going up to town this afternoon and see a few moving pictures."

"Moving pictures?" Grace paused at the door, an expression of the utmost astonishment upon her face. "Why, Dick, you never go to moving pictures. You've always said they didn't interest you."

"We're going, just the same."

"What's come over you?" Grace asked.

"Nothing. I'm curious to see some of them, that's all. Never too old to learn, you know. If I am not mistaken, I saw a new feature film advertised in the newspaper this morning." He took a paper from the desk and glanced through it. "Here it is. Ruth Morton, in The Miser's Daughter. Have you seen it?"

"No. But I've seen Miss Morton often—in pictures, I mean. She's a lovely creature, and a splendid actress, too."

"Then this film ought to be a good one, don't you think?"

Grace burst into a rippling laugh.

"You're getting positively human, Richard," she exclaimed. "Here I've been telling you for months past what a lot you've been missing, and you only made fun of me, and now you actually suggest going yourself. Was the lady who called interested in the motion picture business?"

Duvall laughed, but made no reply.

"What's the mystery?" Grace went on, with an amused smile. "You haven't told me, you know. Has she lost her jewels, or only her husband?"

Duvall raised his hand.

"No questions, my dear. This is a professional matter. But I don't mind telling you this much, if I ever become a motion picture 'fan,' you'll have her to thank for it."

"Really. Then I'm glad she came. I hate going alone. And it seems I shall also have to thank her for a trip to New York. She has my eternal gratitude. Now I'm going up to pack."

Duvall resumed his seat, and once more took up his examination of the letters Mrs. Morton had left with him, but they told him little. There were the usual individual peculiarities in the typewritten characters, but that was about all he could discover. The letter paper, while of excellent quality, was such as might be bought at any first-class stationery store. The death's head seal, of course, was highly individual, but to trace anyone by means of it presented almost insuperable difficulties. To find the seal, one must of necessity first find its owner, and then the chase would be over. He replaced the letters in his pocket book, and went to his room to make ready for their journey.