There was a sound of retreating footsteps, and I heard the entrance door close quietly.

CHAPTER XVIII

WHAT CAME THROUGH THE WINDOW

I had not been in my unnatural position for many minutes before I began to suffer agonies, agonies not only physical but mental; for standing there like some prisoner of the Inquisition, it came to me how this dismantled apartment must be the focus of the dreadful forces of Hassan of Aleppo!

That Earl Dexter had the slipper of the Prophet I no longer doubted, and that he had sustained, in this dwelling beneath the roof, an uncanny siege during the days which had passed since the theft from the Antiquarian Museum, was equally certain.  Helpless, gagged, I pictured those hideous creatures, evil products of the secret East, who might, nay, who must surround that place!  I thought of the horrible little yellow man who lay dead in Wyatt’s Buildings; and it became evident to me that the house in which I was now imprisoned must overlook the back of those unsavoury tenements.  The windows, sack-covered now, no doubt commanded a view of the roofs of the buildings.  One of the mysteries that had puzzled us was solved.  It was Earl Dexter who had shot the yellow dwarf as he was bound for this very room!  But how humanly the Hashishin had proposed to gain his goal, how he had travelled through empty space—­for from empty space the shot had brought him down—­I could not imagine.

I knew something of the almost supernatural attributes of these people.  From Professor Deeping’s book I knew of the incredible feats which they could perform when under the influence of the drug hashish.  From personal experience also I knew that they had powers wholly abnormal.

The pain in my arms and back momentarily increased.  An awesome silence ruled.  I tortured myself with pictures of murderous yellow men possessed of the power claimed by the Mahatmas, of levitation.  Mentally I could see a distorted half-animal creature carrying a great gleaming knife and floating supernaturally toward me through the night!

A soft pattering sound became perceptible on the sloping roof above!

I think I have never known such intense and numbing fear as that which now descended upon me.  Perhaps I may be forgiven it.  A more dreadful situation it would be hard to devise.  Knowing that I was on the fifth story of a house, bound, helpless, I knew, too, that a second mystic guardian of the slipper was come to accomplish the task in which the first had failed!

I began to pray fervently.

Neither of the windows were closed; and now through the intense darkness I heard one of them being raised up—­up—­up . . .

The sacking was pulled aside inch by inch.

Silhouetted against the faintly luminous background I saw a hunched, unnatural figure.  The real was more dreadful even than the imaginary—­for some stray beam of light touched into cold radiance a huge curved knife which the visitant held between his teeth!