and down outside, Petrie. Everyone has cleared off now. It is getting late. Keep your eyes open and be on your guard. I thought I had the start, but he is here before me, and, what is worse, he probably knows by now that I am here, too."
With which he entered the house and left me out in the square, with leisure to think, to try to understand.
The crowd which usually haunts the scene of a sensational crime had been cleared away, and it had been circulated that Sir Crichton had died from natural causes. The intense heat having driven most of the residents out of town, practically I had the square to myself, and I gave myself up to a brief consideration of the mystery in which I so suddenly had found myself involved.
By what agency had Sir Crichton met his death? Did Nayland Smith know? I rather suspected that he did. What was the hidden significance of the perfumed envelope? Who was that mysterious personage whom Smith so evidently dreaded, who had attempted his life, who, presumably, had murdered Sir Crichton? Sir Crichton Davey, during the time that he had held office in India, and during his long term of service at home, had earned the good will of all, British and native alike. Who was his secret enemy?
Something touched me lightly on the shoulder.
I turned, with my heart fluttering like a child's. This night's work had imposed a severe strain even upon my callous nerves.
A girl wrapped in a hooded opera-cloak stood at my elbow, and, as she glanced up at me, I thought that I never had seen a face so seductively lovely nor of so unusual a type. With the skin of a perfect blonde, she had eyes and lashes as black as a Creole's, which, together with her full red lips, told me that this beautiful stranger, whose touch had so startled me, was not a child of our northern shores.
"Forgive me," she said, speaking with an odd, pretty accent, and laying a slim hand, with jeweled fingers, confidingly upon my arm, "if I startled you. But—is it true that Sir Crichton Davey has been—murdered?"
I looked into her big, questioning eyes, a harsh suspicion laboring in my mind, but could read nothing in their mysterious depths—only I wondered anew at my questioner's beauty. The grotesque idea momentarily possessed me that, were the bloom of her red lips due to art and not to nature, their kiss would leave—though not indelibly—just such a mark as I had seen upon the dead man's hand. But I dismissed the fantastic notion as bred of the night's horrors, and worthy only of a mediaeval legend. No doubt she was some friend or acquaintance of Sir Crichton who lived close by.
"I cannot say that he has been murdered," I replied, acting upon the latter supposition, and seeking to tell her what she asked as gently as possible.
"But he is—Dead?"
She closed her eyes and uttered a low, moaning sound, swaying dizzily. Thinking she was about to swoon, I threw my arm round her shoulder to support her, but she smiled sadly, and pushed me gently away.
"I am quite well, thank you," she said.
"You are certain? Let me walk with you until you feel quite sure of yourself."
She shook her head, flashed a rapid glance at me with her beautiful eyes, and looked away in a sort of sorrowful embarrassment, for which I was entirely at a loss to account. Suddenly she resumed:
"I cannot let my name be mentioned in this dreadful matter, but—I think I have some information—for the police. Will you give this to—whomever you think proper?"
She handed me a sealed envelope, again met my eyes with one of her dazzling glances, and hurried away. She had gone no more than ten or twelve yards, and I still was standing bewildered, watching her graceful, retreating figure, when she turned abruptly and came back.
Without looking directly at me, but alternately glancing towards a distant corner of the square and towards the house of Major-General Platt-Houston, she made the following extraordinary request:
"If you would do me a very great service, for which I always would be grateful,"—she glanced at me with passionate intentness—"when you have given my message to the proper person, leave him and do not go near him any more to-night!"
Before I could find words to reply she gathered up her cloak and ran. Before I could determine whether or not to follow her (for her words had aroused anew all my worst suspicions) she had disappeared! I heard the whir of a restarted motor at no great distance, and, in the instant that Nayland Smith came running down the steps, I knew that I had nodded at my post.
"Smith!" I cried as he joined me, "tell me what we must do!" And rapidly I acquainted him with the incident.
My friend looked very grave; then a grim smile crept round his lips.
"She was a big card to play," he said; "but he did not know that I held one to beat it."
"What! You know this girl! Who is she?"
"She is one of the finest weapons in the enemy's armory, Petrie. But a woman is a two-edged sword, and treacherous. To our great good fortune, she has formed a sudden predilection, characteristically Oriental, for yourself. Oh, you may scoff, but it is evident. She was employed to get this letter placed in my hands. Give it to me."
I did so.
"She has succeeded. Smell."
He held the envelope under my nose, and, with a sudden sense of nausea, I recognized the strange perfume.
"You know what this presaged in Sir Crichton's case? Can you doubt any longer? She did not want you to share my fate, Petrie."
"Smith," I said unsteadily, "I have followed your lead blindly in this horrible business and have not pressed for an explanation, but I must insist before I go one step farther upon knowing what it all means."
"Just a few steps farther," he rejoined; "as far as a cab. We are hardly safe here. Oh, you need not fear shots or knives. The man whose servants are watching us now scorns to employ such clumsy, tell-tale weapons."
Only three cabs were on the rank, and, as we entered the first, something hissed past my ear, missed both Smith and me by a miracle, and, passing over the roof of the taxi, presumably fell in the enclosed garden occupying the center of the square.
"What was that?" I cried.
"Get in—quickly!" Smith rapped back. "It was attempt number one! More than that I cannot say. Don't let the man hear. He has noticed nothing. Pull up the window on your side, Petrie, and look out behind. Good! We've started."
The cab moved off with a metallic jerk, and I turned and looked back through the little window in the rear.
"Someone has got into another cab. It is following ours, I think."
Nayland Smith lay back and laughed unmirthfully.
"Petrie," he said, "if I escape alive from this business I shall know that I bear a charmed life."
I made no reply, as he pulled out the dilapidated pouch and filled his pipe.
"You have asked me to explain matters," he continued, "and I will do so to the best of my ability. You no doubt wonder why a servant of the British Government, lately stationed in Burma, suddenly appears in London, in the character of a detective. I am here, Petrie—and I bear credentials from the very highest sources—because, quite by accident, I came upon a clew. Following it up, in the ordinary course of routine, I obtained evidence of the existence and malignant activity of a certain man. At the present stage of the case I should not be justified in terming him the emissary of an Eastern Power, but I may say that representations are shortly to be made to that Power's ambassador in London."
He paused and glanced back towards the pursuing cab.
"There is little to fear until we arrive home," he said calmly. "Afterwards there is much. To continue: This man, whether a fanatic or a duly appointed agent, is, unquestionably, the most malign and formidable personality existing in the known world today. He is a linguist who speaks with almost equal facility in any of the civilized languages, and in