"We are dealing now," said Nayland Smith, pacing restlessly up and down our sitting-room, "not, as of old, with Dr. Fu-Manchu, but with an entirely unknown quantity—the Si-Fan."  
"For Heaven's sake!" I cried, "what is the Si-Fan?"
 
"The greatest mystery of the mysterious East, Petrie. Think. You know, as I know, that a malignant being, Dr. Fu-Manchu, was for some time in England, engaged in 'paving the way' (I believe those words were my own) for nothing less than a giant Yellow Empire. That dream is what millions of Europeans and Americans term 'the Yellow Peril! Very good. Such an empire needs must have——"
 
"An emperor!"
 
Nayland Smith stopped his restless pacing immediately in front of me.
 
"Why not an empress, Petrie!" he rapped.
 
His words were something of a verbal thunderbolt; I found myself at loss for any suitable reply.
 
"You will perhaps remind me," he continued rapidly, "of the lowly place held by women in the East. I can cite notable exceptions, ancient and modern. In fact, a moment's consideration by a hypothetical body of Eastern dynast-makers not of an emperor but of an empress. Finally, there is a persistent tradition throughout the Far East that such a woman will one day rule over the known peoples. I was assured some years ago, by a very learned pundit, that a princess of incalculably ancient lineage, residing in some secret monastery in Tartary or Tibet, was to be the future empress of the world. I believe this tradition, or the extensive group who seek to keep it alive and potent, to be what is called the Si-Fan!"
 
I was past greater amazement; but—
 
"This lady can be no longer young, then?" I asked.
 
"On the contrary, Petrie, she remains always young and beautiful by means of a continuous series of reincarnations; also she thus conserves the collated wisdom of many ages. In short, she is the archetype of Lamaism. The real secret of Lama celibacy is the existence of this immaculate ruler, of whom the Grand Lama is merely a high priest. She has, as attendants, maidens of good family, selected for their personal charms, and rendered dumb in order that they may never report what they see and hear."
 
"Smith!" I cried, "this is utterly incredible!"
 
"Her body slaves are not only mute, but blind; for it is death to look upon her beauty unveiled."
 
I stood up impatiently.
 
"You are amusing yourself," I said.
 
Nayland Smith clapped his hands upon my shoulders, in his own impulsive fashion, and looked earnestly into my eyes.
 
"Forgive me, old man," he said, "if I have related all these fantastic particulars as though I gave them credence. Much of this is legendary, I know, some of it mere superstition, but—I am serious now, Petrie— part of it is true."
 
I stared at the square-cut, sun-tanned face; and no trace of a smile lurked about that grim mouth. "Such a woman may actually exist, Petrie, only in legend; but, nevertheless, she forms the head center of that giant conspiracy in which the activities of Dr. Fu-Manchu were merely a part. Hale blundered on to this stupendous business; and from what I have gathered from Beeton and what I have seen for myself, it is evident that in yonder coffer"—he pointed to the brass chest standing hard by—"Hale got hold of something indispensable to the success of this vast Yellow conspiracy. That he was followed here, to the very hotel, by agents of this mystic Unknown is evident. But," he added grimly, "they have failed in their object!"
 
A thousand outrageous possibilities fought for precedence in my mind.
 
"Smith!" I cried, "the half-caste woman whom I saw in the hotel …"
 
Nayland Smith shrugged his shoulders.
 
"Probably, as M. Samarkan suggests, an ayah!" he said; but there was an odd note in his voice and an odd look in his eyes.
 
"Then again, I am almost certain that Hale's warning concerning 'the man with the limp' was no empty one. Shall you open the brass chest?"
 
"At present, decidedly no. Hale's fate renders his warning one that
I dare not neglect. For I was with him when he died; and they cannot
know how much I know. How did he die? How did he die? How was the
Flower of Silence introduced into his closely guarded room?"
 
"The Flower of Silence?"
 
Smith laughed shortly and unmirthfully.
 
"I was once sent for," he said, "during the time that I was stationed in Upper Burma, to see a stranger—a sort of itinerant Buddhist priest, so I understood, who had desired to communicate some message to me personally. He was dying—in a dirty hut on the outskirts of Manipur, up in the hills. When I arrived I say at a glance that the man was a Tibetan monk. He must have crossed the river and come down through Assam; but the nature of his message I never knew. He had lost the power of speech! He was gurgling, inarticulate, just like poor Hale. A few moments after my arrival he breathed his last. The fellow who had guided me to the place bent over him—I shall always remember the scene—then fell back as though he had stepped upon an adder.
 
"'He holds the Flower Silence in his hand!' he cried—'the Si-Fan! the
Si-Fan!'—and bolted from the hut."
 
"When I went to examine the dead man, sure enough he held in one hand a little crumpled spray of flowers. I did not touch it with my fingers naturally, but I managed to loop a piece of twine around the stem, and by that means I gingerly removed the flowers and carried them to an orchid-hunter of my acquaintance who chanced to be visiting Manipur.
 
"Grahame—that was my orchid man's name—pronounced the specimen to be an unclassified species of jatropha; belonging to the Curcas family. He discovered a sort of hollow thorn, almost like a fang, amongst the blooms, but was unable to surmise the nature of its functions. He extracted enough of a certain fixed oil from the flowers, however, to have poisoned the pair of us!"
 
"Probably the breaking of a bloom …"
 
"Ejects some of this acrid oil through the thorn? Practically the uncanny thing stings when it is hurt? That is my own idea, Petrie. And I can understand how these Eastern fanatics accept their sentence— silence and death—when they have deserved it, at the hands of their mysterious organization, and commit this novel form of hara-kiri. But I shall not sleep soundly with that brass coffer in my possession until I know by what means Sir Gregory was induced to touch a Flower of Silence, and by what means it was placed in his room!"
 
"But, Smith, why did you direct me to-night to repeat the words,
'Sâkya Mûni'?"
 
Smith smiled in a very grim fashion.
 
"It was after the episode I have just related that I made the acquaintance of that pundit, some of whose statements I have already quoted for your enlightenment. He admitted that the Flower of Silence was an instrument frequently employed by a certain group, adding that, according to some authorities, one who had touched the flower might escape death by immediately pronouncing the sacred name of Buddha. He was no fanatic himself, however, and, marking my incredulity, he explained that the truth was this;—
 
"No one whose powers of speech were imperfect could possibly pronounce correctly the words 'Sâkya Mûni.' Therefore, since the first effects of this damnable thing is instantly to tie the tongue, the uttering of the sacred name of Buddha becomes practically a test whereby the victim my learn whether the venom has entered his system or not!"
 
I repressed a shudder. An atmosphere of horror seemed to be enveloping us, foglike.
 
"Smith," I said slowly, "we must be on our guard," for at last I had run to earth that elusive memory. "Unless I am strangely mistaken, the 'man' who so mysteriously entered Hale's room and the supposed ayah whom I met downstairs are one and the same. Two, at least, of the Yellow group are actually here in the New Louvre!"
 
The light of the shaded lamp shone down upon the brass coffer on the table beside me. The fog seemed to have cleared from the room somewhat, but since in the midnight stillness I could detect the muffled sounds of sirens from the river and the reports of fog signals from the railways, I concluded that the night was not yet wholly clear of the choking mist. In accordance with a pre-arranged scheme we had decided to guard "the key of India" (whatever it might be) turn and turn about through the night. In a word—we feared to sleep unguarded. Now my watch informed me that four o'clock approached, at which hour I was to arouse Smith and retire to sleep to my own bedroom.
 
Nothing had disturbed my vigil—that is, nothing definite. True once, about half an hour earlier, I had thought I heard the dragging and tapping sound from somewhere up above me; but since the corridor overhead was unfinished and none of the rooms opening upon it yet habitable, I concluded that I had been mistaken. The stairway at the end of our corridor, which communicated with that above, was still blocked with bags of cement and slabs of marble, in fact.
 
Faintly to my ears came the booming of London's clocks, beating out the hour of four. But still I sat beside the mysterious coffer, indisposed to awaken my friend any sooner than was necessary, particularly since I felt in no way sleepy myself.
 
I was to learn a lesson that night: the lesson of strict adherence to a compact. I had arranged to awaken Nayland Smith at four; and because I dallied, determined to finish my pipe ere entering his bedroom, almost it happened that Fate placed it beyond my power ever to awaken him again.
 
At ten minutes past four, amid a stillness so intense that the creaking of my slippers seemed a loud disturbance, I crossed the room and pushed open the door of Smith's bedroom. It was in darkness, but as I entered I depressed the switch immediately inside the door, lighting the lamp which swung form the center of the ceiling.
 
Glancing towards the bed, I immediately perceived that there was something different in its aspect, but at first I found this difference difficult to define. I stood for a moment in doubt. Then I realized the nature of the change which had taken place.
 
A lamp hung above the bed, attached to a movable fitting, which enabled it to be raised or lowered at the pleasure of the occupant. When Smith had retired he was in no reading mood, and he had not even lighted the reading-lamp, but had left it pushed high up against the ceiling.
 
It was the position of this lamp which had changed. For now it swung so low over the pillow that the silken fringe of the shade almost touched my friend's face as he lay soundly asleep with one lean brown hand outstretched upon the coverlet.
 
I stood in the doorway staring, mystified, at this phenomenon; I might have stood there without intervening, until intervention had been too late, were it not that, glancing upward toward the wooden block from which ordinarily the pendant hung, I perceived that no block was visible, but only a round, black cavity from which the white flex supporting the lamp swung out.
 
Then, uttering a horse cry which rose unbidden to my lips, I sprang wildly across the room … for now I had seen something else!
 
Attached to one of the four silken tassels which ornamented the lamp-shade, so as almost to rest upon the cheek of the sleeping man, was a little corymb of bloom … the Flower of Silence!
 
Grasping the shade with my left hand I seized the flex with my right, and as Smith sprang upright in bed, eyes wildly glaring, I wrenched with all my might. Upward my gaze was set; and I glimpsed a yellow hand, with long, pointed finger nails. There came a loud resounding snap; an electric spark spat venomously from the circular opening above the bed; and, with the cord and lamp still fast in my grip, I went rolling across the carpet—as the other lamp became instantly extinguished.
 
Dimly I perceived Smith, arrayed in pyjamas, jumping out upon the opposite side of the bed.
 
"Petrie, Petrie!" he cried, "where are you? what has happened?"
 
A laugh, little short of hysterical, escaped me. I gathered myself up and made for the lighted sitting-room.
 
"Quick, Smith!" I said—but I did not recognize my own voice. "Quick— come out of that room."
 
I crossed to the settee, and shaking in every limb, sank down upon it. Nayland Smith, still wild-eyed, and his face a mask of bewilderment, came out of the bedroom and stood watching me.
 
"For God's sake what has happened, Petrie?" he demanded, and began clutching at the lobe of his left ear and looking all about the room dazedly.
 
"The Flower of Silence!" I said; "some one has been at work in the top corridor…. Heaven knows when, for since we engaged these rooms we have not been much away from them … the same device as in the case of poor Hale…. You would have tried to brush the thing away …"
 
A light of understanding began to dawn in my friend's eyes. He drew himself stiffly upright, and in a loud, harsh voice uttered the words: "Sâkya Mûni"—and again: "Sâkya Mûni."
 
"Thank God!" I said shakily. "I was not too late."
 
Nayland Smith, with much rattling of glass, poured out two stiff pegs from the decanter. Then—
 
"_Ssh!_what's that?" he whispered.
 
He stood, tense, listening, his head cast slightly to one side.
 
A very faint sound of shuffling and tapping was perceptible, coming, as I thought, from the incomplete stairway communicating with the upper corridor.
 
"The man with the limp!" whispered Smith.
 
He bounded to the door and actually had one hand upon the bolt, when he turned, and fixed his gaze upon the brass box.
 
"No!" he snapped; "there are occasions when prudence should rule.
Neither of us must leave these rooms to-night!"