And thus we made our compact. Half-an-hour after I was driving in the dog-cart through the pouring rain up the hill out of gray old Dumfries to my uncle's house.

As I descended from the cart and gave it over to a groom, old Davis, the butler, came forward, saying in a low voice:

"There's Miss Leithcourt waiting to see you, Mr. Gordon. She's in the morning-room, and been there an hour. She asked me not to tell anyone else she's here, sir."

"Then my aunt has not seen her?" I exclaimed, scenting mystery in this unexpected visit.

"No, sir. She wishes to see you alone, sir."

I walked across the big hall and along the corridor to the room the old man had indicated.

And as I opened the door and Muriel Leithcourt in plain black rose to meet me, I plainly saw from her white, haggard countenance that something had happened-that she had been forced by circumstances to come to me in strictest confidence.

Was she, I wondered, about to reveal to me the truth?

"Mr. Gregg," exclaimed the girl with agitation, as she put forth her black-gloved hand, "I-I suppose you know-you've heard all about the discovery to-day up at the wood? I need not tell you anything about it"

"Yes, Miss Leithcourt, I only wish you would tell me about it," I said gravely, inviting her to a chair and seating myself. "I've heard some extraordinary story about a man being found dead, but I've been in Dumfries nearly all day. Who is the man?"

"Ah! that we don't know," she replied, pale-faced and anxious. Her attitude was as though she wished to confide in me and yet still hesitated to do so.

"You've been waiting for me quite a long time, Davis tells me. I regret that you should have done this. If you had left word that you wished to see me, I would have come over to you at once."

"No. I wanted to see you alone-that's the reason I am here. They must not know at home that I've been over here, so I purposely asked the man not to announce me to your aunt."

"You want to see me privately," I said in a low, earnest voice. "Why? Is there any service I can render you?"

"Yes. A very great one," she responded with quick eagerness, "I-well-the fact is, I have summoned courage to come to you and beg of you to help me. I am in great distress-and I have not a single friend whom I can trust-in whom I can confide."

"I shall esteem it the highest honor if you will trust me," I said in deep earnestness. "I can only assure you that I will remain loyal to your interests and to yourself."

"Ah! I believe you will, Mr. Gregg!" she declared with enthusiasm, her large, dark eyes turned upon me-the eyes of a woman in sheer and bitter despair. Her face was perfect, one of the most handsome I had ever gazed upon. The more I saw of her the greater was the fascination she held over me.

A silence fell between us as she sat with her gloved hands lying idly in her lap. Her lips moved nervously, but no sound came from them, so agitated was she, so eager to tell me something; and yet at the same time reluctant to take me into her confidence.

"Well?" I asked at last in a low voice. "I am quite ready to render you any service, if you will only command me."

"Ah! But I fear what I require will strike you as so unusual-you will hesitate to act when I explain what service I require of you," she said doubtfully.

"I cannot tell you until I hear your wishes," I said, smiling, and yet puzzled at her attitude.

"It concerns the terrible discovery made up in Rannoch Wood," she said in a hoarse, nervous voice at last. "That unknown man was murdered-stabbed to the heart."

"Well?"

"Well," she said, scarcely above a whisper, "I have suspicions."

"Of the murdered man's identity?"

"No. Of the assassin."

I glanced at her sharply and saw the intense look in her dark, wide-open eyes.

"You believe you know who dealt the blow?"

"I have a suspicion-that is all. Only I want you to help me, if you will."

"Most certainly," I responded. "But if you believe you know the assassin you probably know something of the victim?"

"Only that he looked like a foreigner."

"Then you have seen him?" I exclaimed, much surprised.

My remark caused her to hold her breath for an instant. Then she answered, rather lamely, it seemed to me:

"I saw him when the keepers brought the body to the castle."

Now, according to the account I had heard, the police had conveyed the dead man direct from the wood into Dumfries. Was it possible, therefore, that she had seen Olinto before he met with his sudden end?

I feared to press her for an explanation at that moment, but, nevertheless, the admission that she had seen him struck me as a very peculiar fact.

"You judge him to be a foreigner?" I remarked as casually as I could.

"From his features and complexion I guessed him to be Italian," she responded quickly, at which I pretended to express surprise. "I saw him after the keepers had found him."

"Besides," she went on, "the stiletto was evidently an Italian one, which would almost make it appear that a foreigner was the assassin."

"Is that your own suspicion?"

"No."

"Why?"

She hesitated a moment, then in a low, eager voice she said:

"Because I have already seen that three-edged knife in another person's possession."

"That's pretty strong evidence," I declared. "The person in question will have to prove that he was not in Rannoch Wood last evening at nightfall."

"How do you know it was done at nightfall?" she asked quickly with some surprise, half-rising from her chair.

"I merely surmised that it was," I responded, inwardly blaming myself for my ill-timed admission.

"Ah!" she said with a slight sigh, "there is more mystery in this affair than we have yet discovered, Mr. Gregg. What, I wonder, brought the unfortunate young man up into our wood?"

"An appointment, without a doubt. But with whom?"

She shook her head, saying:

"My father often goes to that spot to shoot pigeon in the evening. He told us so at luncheon to-day. How fortunate he was not there last night, or he might be suspected."

"Yes," I said. "It is a very fortunate circumstance, for it cannot be a pleasant experience to be under suspicion of being an assassin. He was at home last night, was he?" I added casually.

"Of course. Don't you recollect that when you called he chatted with you? I did some typewriting for him in the study, and we were together all the afternoon-or at least till nearly five o'clock, when we went out into the hall to tea."

"Then what is your theory regarding the affair?" I inquired, rather puzzled why she should so decisively prove an alibi for her father.

"It seems certain that the poor fellow went to the wood by appointment, and was killed. But have you been up to the spot since the finding of the body?"

"No. Have you?"

"Yes. The affair interested me, and as soon as I recognized the old Italian knife in the hand of the keeper, I went up there and looked about. I am glad I did so, for I found something which seems to have escaped the notice of the detectives."

"And what's that?" I asked eagerly.

"Why, about three yards from the pool of blood where the unfortunate foreigner was found is another small pool of blood where the grass and ferns around are all crushed down as though there had been a struggle there."

"There may have been a struggle at that spot, and the man may have staggered some distance before he fell dead."

"Not if he had been struck in the heart, as they say. He would fall, would he not?" she suggested. "No. The police seem very dense, and this plain fact has not yet occurred to them. Their theory is the same as what you suggest, but my own is something quite different, Mr. Gregg. I believe that a second person also fell a victim," she added in a low, distinct tone.