Partially removing the dust from my smarting eyes, I returned to the embrasure, and stepping from the chair on to the deep ledge, I grasped the corner of the quaint, diamond-paned window, which I had opened to its fullest extent, and craned forth.

Now I could see the ivy-grown battlements surmounting the tower (the east wing, in which my room was situated, was the oldest part of Graywater Park).  Sharply outlined against the cloudless sky they showed ... and the black silhouette of a man’s head and shoulders leant over directly above me!

I drew back sharply.  The climber, I thought, had not seen me, although he was evidently peering down at my window.  What did it mean?

As I crouched in the embrasure, a sudden giddiness assailed me, which at first I ascribed to a sympathetic nervous action due to having seen the man poised there at that dizzy height.  But it increased, I swayed forward, and clutched at the wall to save myself.  A deadly nausea overcame me ... and a deadly doubt leapt to my mind.

In the past, Sir Lionel Barton had had spies in his household; what if the dark-faced Greek, Homopoulo, were another of these?  I thought of the ’45 port, of the ghostly rapping; and I thought of the man who crouched upon the roof of the tower above my open window.

My symptoms now were unmistakable; my head throbbed and my vision grew imperfect; there had to be an opiate in the wine!

I almost fell back into the room.  Supporting myself by means of the chair, the chest of drawers, and finally, the bed-rail, I got to my grip, and with weakening fingers, extracted the little medicine-chest which was invariably my traveling companion.

* * * * * *

Grimly pitting my will against the drug, but still trembling weakly from the result of the treatment, internal and subcutaneous, which I had adopted, I staggered to the door out into the corridor and up the narrow, winding stairs to Smith’s room.  I carried an electric pocket-lamp, and by its light I found my way to the triangular, paneled landing.

I tried the handle.  As I had expected, the door was locked.  I beat upon it with my fist.

“Smith!” I cried—­“Smith!”

There was no reply.

Again I clamored; awaking ancient echoes within the rooms and all about me.  But nothing moved and no answering voice rewarded my efforts; the other rooms were seemingly unoccupied, and Smith—­was drugged!

My senses in disorder, and a mist dancing before my eyes, I went stumbling down into the lower corridor.  At the door of my own room I paused; a new fact had suddenly been revealed to me, a fact which the mazy windings of the corridors had hitherto led me to overlook.  Smith’s room was also in the east tower, and must be directly above mine!

“My God!” I whispered, thinking of the climber—­“he has been murdered!”

I staggered into my room and clutched at the bed-rail to support myself, for my legs threatened to collapse beneath me.  How should I act?  That we were victims of a cunning plot, that the deathful Si-Fan had at last wreaked its vengeance upon Nayland Smith I could not doubt.