Miss Wolcott received Lyon with the same curiously cold and impersonal manner that had struck him before, but unless he deceived himself, it was a manner deliberately assumed this time to conceal some unwonted nervousness of which she was herself afraid. Her face was as Sphinx-like as ever, but there was an unevenness of tension in her voice which betrayed emotion.

"I sent for you because something curious has happened," she said abruptly, "and I don't know anyone else to talk it over with. I received yesterday, by mail, this letter." And she handed him a single sheet of note paper, on which was written, in a bold hand,

"Remember, I said living or dead.

"Warren Fullerton."

Lyon looked up at her in amaze. "You received this yesterday?"

"Yes."

"Are you familiar with Mr. Fullerton's handwriting?"

"Yes. It is his."

"Can you be positive about that?"

He thought she suppressed a shudder, but her voice was coldly calm as she answered, "I do not think I can be deceived in it. I know it very well."

"May I see the envelope?"

She handed it to him silently. It corresponded with the paper, was addressed to her in the same bold, assured hand, and the postmark was particularly plain. It had been mailed the day it had been delivered. The note and envelope were both made of a thin peculiar grayish-green paper, oriental in appearance, with a faint perfume about them that would have been dizzying if more pronounced. Lyon held the paper up to the light. It vas watermarked, but so faintly that he had to study it carefully before he made out that the design was that of a coiled serpent with hooded head. As he moved the paper to bring out the outline, the coils seemed to change and move and melt into one another. Certainly it would have been a difficult paper to duplicate.

"Was Mr. Fullerton in the habit of using this paper?"

"Yes. It was made for him. He was given to fads like that. And another thing, though a trifle. You will notice he uses two green one-cent stamps, instead of the red two. He always stamped the letters written on that paper with green stamps."

"Does the message convey any special meaning to you?"

Miss Wolcott waited a moment before replying, as though to gather her self-control into available form. "I was at one time engaged to be married to Mr. Fullerton. I was very young and romantic and--silly. I had not known him very long. And almost immediately I had to go east to spend three months with some friends. While I was away I wrote to Mr. Fullerton,--very silly letters. After I came back something happened that made me change my mind and my feelings towards him. I broke the engagement and sent him back his letters and presents. He refused to be released or to release me. It was a very terrible time. He said that if ever I should marry anyone else, he would send my love-letters to him to my husband,--and this whether he was alive or dead."

"Ah! That explains, you think, this phrase?"

"I am sure of it."

"Did the threat make any special impression on you at the time? I mean did it influence your actions at all?"

"It made me determine never to think of marrying." Then, in answer to Lyon's look of surprise, she added, impetuously, "I would rather die than have anyone read those letters. I simply could not think of it. No man's love could stand such a test. To know that his wife had said such silly, silly things to another man,--it would be intolerable."

"But no gentleman would read them."

She shrugged her shoulders lightly. "In a play, no. But in real life, he would be very curious. Or, if he did not read them, he still could not forget them. He would have them in his mind, and would perhaps guess them worse than they were. Besides, you do not know Mr. Fullerton. He would have managed in some way to bring about what he wanted. I cannot guess how, but those letters would have been put where they must be read. He was not one to trip in his plans."

"Did you make any attempt to recover your letters?"

She did not answer at once, and glancing at her Lyon saw that the agitation which she had been holding back seemed to have swept her for a moment beyond her own control. She was trembling so violently that she could not speak, and only the forcible pressure of her slender hands upon the arms of her chair gave her steadiness enough to hold her emotions in check. He turned to the light and busied himself for a minute in a critical examination of the letter. Then he came back to his question--for he was of no mind to let it pass unanswered.

"Did you ever try to recover the letters?"

"Once," she said, in a very low voice.

"And you failed?"

"Worse than failed." She threw out her hand toward the note he still held. "Did he not say, living or dead? Mere death could not interfere when he had set his will upon revenge."

"Then whoever wrote this note," said Lyon, thoughtfully, "must have had knowledge of his purposes as well as access to his private desk and knowledge of his personal peculiarities in regard to stamps. Now, Miss Wolcott, you must help me. Who would be likely to know of your letters?"

"How can I tell? I have hardly seen him for four years until--" She broke off, leaving the sentence unfinished.

"Have you spoken of them yourself to anyone? Any girl friend?"

"No, never."

"To your family?"

"No. I have lived alone with my grandfather since I was fifteen. You know him,--I love him, but he is no confidant for a young girl. I have always been much alone."

"Then, so far as you know, no one could have learned from you of those letters?"

"No one."

"Not Arthur Lawrence, for instance?"

She started, and looked as though he had presented a new idea.

"I never spoke of them," she said, slowly.

"Did he know of your engagement to Fullerton?"

"He never referred to it, but it is probable that he had heard of it. Some one would have mentioned it, probably. I did not know Mr. Lawrence at that time."

"He had no reason then to know--or to guess--the importance which you placed upon the recovery of the letters?"

She looked distressed, but her glance was as searching as his own.

"Why do you ask that? What bearing has it on this letter?"

"Perhaps none. But I was trying to narrow down the possible actors. If you on your part have kept the knowledge of these letters to yourself inviolately, then the information about them must have been given out by Fullerton if at all. Do you know anyone to whom he would be likely to confide such a matter,--any confidant or chum?"

She shook her head helplessly. "I know nothing of his friends. My impression is that he had very few. He was a strange, solitary, secret man."

"And yet it must be clear that either he wrote this himself, or it was written on his private paper in his handwriting, by someone who had intimate knowledge of his affairs,--not only of the fact that he had those letters of yours, but of the threat which he held over you in regard to them. Now if he wrote it himself, why wasn't it mailed until yesterday? And who did mail it yesterday, anyhow? If someone was in his confidence and is trying to play upon your fears, we must find out who it is. May I take this letter with me?"

"I don't want to ever see it again."

"And if you receive any other letters or anything comes up in any way bearing on this, will you let me know at once? I am going to try to find out about his office help. And I will leave this letter open to the sunlight for a day. If it was written yesterday, the ink will show a change by to-morrow. If written a week ago, it probably will not. As soon as I learn anything that will interest you, I will let you know."

But as he w............