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!"

CHAPTER V

JOHN KI'S

"What is the meaning of Si-Fan?" asked Detective-sergeant Fletcher.

He stood looking from the window at the prospect below; at the trees bordering the winding embankment; at the ancient monolith which for unnumbered ages had looked across desert sands to the Nile, and now looked down upon another river of many mysteries. The view seemed to absorb his attention. He spoke without turning his head.

Nayland Smith laughed shortly.

"The Si-Fan are the natives of Eastern Tibet," he replied.

"But the term has some other significance, sir?" said the detective; his words were more of an assertion than a query.

"It has," replied my friend grimly. "I believe it to be the name, or perhaps the sigil, of an extensive secret society with branches stretching out into every corner of the Orient."

We were silent for awhile. Inspector Weymouth, who sat in a chair near the window, glanced appreciatively at the back of his subordinate, who still stood looking out. Detective-sergeant Fletcher was one of Scotland Yard's coming men. He had