To my surprise, instead of seeming baffled by my statement, Fleming Stone gave me a quizzical glance.

"A perfect alibi?" he repeated. "How do you know?"

"He told me so," I said confidently.

"Why did he tell you that? Did he expect to be accused?"

"No," I replied; "I do not think he did. You know, Mr. Stone, I never met young Lawrence till since this affair; but, unless I am no judge of human nature, he is a frank, honest sort of chap, with a whole lot of common sense, and he said to his cousin, in my presence, that in the course of legal proceedings he might easily be called upon to give an account of his own movements the night of the murder, but that he was prepared to prove a perfect alibi. Therefore, you see, we cannot suspect him, notwithstanding the coincidence of the violet-colored glass."

"He can prove a perfect alibi," again repeated Fleming Stone, and again that strange little gleam of satisfaction crept into his eyes. It irritated while it fascinated me, and I wondered in what direction his suspicions would next turn.

"Did he tell you," he asked, "the nature of this alibi?"

I was struck with a sudden thought. For some reason, the detective even yet suspected George, and all I said seemed to strengthen rather than allay his suspicion. I would, therefore, give the suspected man a chance to speak for himself.

"He did," I answered; "but instead of repeating to you at secondhand what he told me, would it not be better to go down to his place and let him tell it for himself?"

"Very much better," said Stone heartily; and again we started downtown. It was well on toward noon, and it seemed to me we had made no definite progress. After Fleming Stone had told me he would discover the criminal that day, I couldn't help imagining a sudden bringing to book of some burly ruffian whose face was well known in the rogues' gallery, but unfamiliar to those in my walk of life. But Stone's sudden interest in George Lawrence filled me with a vague fear that the trail he was evidently following might somehow implicate Janet before he had finished. However, as I was feeling convinced that George's own testimony would affect Fleming Stone more favorably than my own version of it, I felt glad indeed that we were bound on our present errand.

And so we came again to the house in Washington Square where Lawrence lived.

The young man was at home, and received us in his studio. He seemed no whit embarrassed at the detective's visit, greeted me pleasantly, and expressed himself as quite willing to tell us anything we wanted to know.

"Of course you understand," began Fleming Stone, "that with so few possible witnesses, it is necessary to make a somewhat thorough examination of each one."

"Certainly," said George, whose own affability of manner quite equalled that of the celebrated detective.

"Then," went on Stone, "I will ask you, if you please, to detail your own occupations on last Wednesday."

"Beginning in the morning?" asked George.

"If you please."

"Well, let me see. I didn't get up very early, and after I did rise I stayed around here in my studio until luncheon time. During the morning I worked on several sketches for a book I am doing. About twelve o'clock I went uptown and lunched with a friend, a fellow-artist, at a little German restaurant. After that I went and called for Miss Millicent Waring, whom I had invited to go with me to a matinÉe. I had expected Mrs. Waring to accompany us, but as she was ill she allowed Miss Waring to go with me alone, although it is not Miss Waring's habit to go about unchaperoned."

I couldn't help feeling a certain satisfaction in listening to young Lawrence's story. I was glad that his habits and his friends were all so correct and so entirely free from the unconventionality which is sometimes noticed in the social doings of young artists.

"We went to the matinÉe," continued George, "in Mrs. Waring's carriage, which also came for us, after the performance."

"One moment," said Fleming Stone. "You stopped nowhere, going or coming?"

"No," said Lawrence; "nowhere."

"Except at the florist's," observed Stone quietly.

It may have been my imagination, but I thought that George started at these words. However, he said in a cool, steady voice:

"Ah, yes, I had forgotten that. We stopped a moment to get some violets for Miss Waring."

"And after the matinÉe you drove home with Miss Waring?"

"Yes," said Lawrence; "and left her at her own door. She invited me to come back to dinner, and I said I would. As the Warings' house is only two blocks away from the Pembroke's, I thought I would run in for a few moments to see Janet. I did this, and Janet seemed glad to see me, but Uncle Robert was so crusty and irritable that I did not care to stay very long. I left there about six, came back here to my room, and dressed for dinner. From here I went directly back to the Warings', reaching there at 7.30, which was the dinner hour. There were other guests, and after dinner there was music in the drawing-room. I stayed until eleven o'clock. As I said good-night to Miss Waring, the clock chanced to be striking eleven, so I'm sure of the time. From the Warings' I came right back here on a Broadway car. I reached this house at 11.25, it having taken me about twenty-five minutes to come down from Sixtieth Street and to walk over here from Broadway."

"How do you know you reached this house at exactly 11.25?" Fleming Stone asked this with such an air of cordial interest that there was no trace of cross-questioning about it.

"Because," said George easily, "my watch had stopped—it had run down during the evening—and so as I came into this house I asked the hall boy what time it was, that I might set my watch. He looked at the office clock, and told me. Of course you can verify this by the boy."

"I've no desire to verify your statement, Mr. Lawrence," said Stone, with his winning smile. "It's a bad habit, this letting a watch run down. Do you often do it?"

"No," said Lawrence; "almost never. Indeed, I don't know when it has happened before."

"And then what next, Mr. Lawrence?"

"Then the hall boy brought me up in the elevator, I let myself into my rooms, and went at once to bed."

"Then the first intimation of your uncle's death you received the next morning?"

"Yes, when Janet telephoned to me. But she didn't say Uncle Robert was dead. She merely asked me to come up there at once, and I went."

"What did you think she wanted you for?"

"I thought that either uncle was ill or she was herself, for she had never telephoned for me before in the morning."

"I thank you, Mr. Lawrence," said Fleming Stone, "for your frank and straightforward account of this affair, and for your courteous answers to my questions. You know, of course, that it is the unpleasant duty of a detective to ask questions unmercifully, in the hope of being set upon the right track at last."

"I quite appreciate your position, my dear sir, and I trust I have given you all the information you desire. As I have told Mr. Landon, I have no taste for detective work myself, but I suppose it has to be done by somebody."

After polite good-byes on both sides, we left Lawrence in his studio, and went down-stairs. Mr. Stone insisted on walking down, though it was four flights, and I, of course, raised no objection.

When we reached the ground floor he stepped into the office, which was a small room just at the right of the entrance, and not far from the elevator.

After a glance at the office clock which stood on the desk, Mr. Stone addressed himself to the office boy.

"Do you remember," he said, "that Mr. Lawrence came in here last Wednesday night?"

"Yes, sir," said the boy; "I do."

"At what time was it?"

"Just twenty-five minutes after eleven, sir."

"How can you fix the time so exactly, my boy?"

"Because when Mr. Lawrence came in, his watch had stopped, and he asked me what time it was by the office clock."

"Couldn't he see for himself?"

"I suppose he could, sir, but, any way, he asked me, and I told him; and then I took him up in the elevator, and he was setting his watch on the way up. Just before he got out he said: 'Did you say 11.25?' and I said, 'Yes.'"

"The office clock is always about right, I suppose?" said Mr. Stone, and, taking his watch from his pocket, he compared the two. There was but a minute's difference.

"Yes, sir, just about right; but that night I thought it was later when Mr. Lawrence come in. I was surprised myself when I see it wasn't half past eleven yet. But, of course, I must have made a mistake, for this clock is never more than a couple of minutes out of the way."

"What time does your elevator stop running?"

"Not at all, sir, we run it all night."

"And other men came in after Mr. Lawrence did that night?"

"Oh, yes, sir; lots of them. These is bachelor apartments, you know, and the men come in quite late—sometimes up till two or three o'clock."

Apparently Fleming Stone had learned all he wanted to know from the boy, and after he had thanked him and had also slipped into his hand a bit of more material reward, the interview was at an end.

We went out into the street again, and Fleming Stone said: "Now I should like to examine the Pembrokes' apartment."

"And shall you want to interview Miss Pembroke?" I inquired.

"Yes, I think so," he replied; "but we will look over the apartment first."

"We'll have something to eat first," I declared; "and if you'll come home with me, I'll guarantee that my sister will give you quite as satisfactory a luncheon as you could obtain in the best hotel in the city."

"I've no doubt of it," said Stone pleasantly; "and I accept your invitation with pleasure. Will you wait for me a minute, while I telephone?"

Before I had time to reply he had slipped in through a doorway at which hung the familiar blue sign.

In a minute or two he rejoined me, and said: "Now let's dismiss the whole affair from our minds until after luncheon. It is never wise to let business interfere with digestion."

As we rode up home in the car, Mr. Stone was most agreeable and entertaining. Not a word was said of the Pembroke case—he seemed really to have laid aside all thought of it—and yet I couldn't help a sinister conviction that when he telephoned it had been a message to headquarters, authorizing the surveillance, if not the arrest, of somebody. It couldn't be Lawrence, in the face of that alibi; it couldn't be Janet, for he knew next to nothing about her connection with the matter; it couldn't be Charlotte, of course; and so it must have been "some person or persons unknown" to me.

I felt no hesitancy, so far as Laura was concerned, in taking home an unexpected guest, for it was my habit to do that whenever I chose, and I had never found Laura otherwise than pleased to see my friends, and amply able to provide hospitality for them. But, as we neared the house, I remembered Janet's strange disinclination to employ a detective, and her apparent horror at the mention of Fleming Stone's name.

Feeling that honesty demanded it, I told Fleming Stone exactly what Janet had said on this subject when I had left the house that morning. Though apparently not disturbed personally by Miss Pembroke's attitude toward him, he seemed to consider it as of definite importance for some other reason.

"Why should Miss Pembroke object to a detective's services," he said, "when, as you have told me, Mr. Lawrence said at your dinner table last night that he wanted to engage the best possible detective skill?"

"I don't know," I replied. "I'm puzzled myself. But I admit, Mr. Stone, that Miss Pembroke has been an enigma to me from the first. Not only do I believe her innocent, but I have a warmer regard for her than I am perhaps justified in mentioning to a stranger; and yet she is so contradictory in her speech and action from time to time that I simply do not know what to think."

Fleming Stone turned a very kind glance on me. "The hardest puzzle in this world," he said, "is a woman. Of course I do not know Miss Pembroke, but I hope she will consent to meet me, notwithstanding her aversion to detectives."

"I think she will," I said; "and, besides, she is so changeable that at this moment she may be more anxious to see a detective than anybody else."

"Let us hope so," he said somewhat gravely. "It may be much to her advantage."