from which had so deeply mystified us. Within a niche in the wall,
a little to the left of the window, rested an object which, at that
moment, claimed our undivided attention the sight of which so
wrought upon us that temporarily all else was forgotten.

It was the red slipper of the Prophet!

"My God!" whispered Carneta--"my God!"--and clutched at me,
swaying dizzily.

A few inches from our feet the floor became depressed, how deeply
I could not determine, for it was filled with water, water filthy
and slimy! The strange, nauseating odour had grown all but
unsupportable; it seemingly proceeded from this fetid pool which,
occupying the floor of the dungeon, offered a barrier, since its
depth was unknown, of fully twelve feet between ourselves and the
farther wall.

There was a faint, dripping sound: a whispering, echoing drip-drip
of falling water. I could not tell from whence it proceeded.

Almost supporting my companion, whose courage seemed suddenly to
have failed her, I stared fascinatedly at that blood-stained
relic. Something then induced me to look behind; I suppose a
warning instinct of that sort which is unexplainable. I only know
that upholding Carneta with my left arm, and nervously grasping my
revolver in my right, I turned and glanced over my shoulder.

Very slowly, but with a constant, regular motion, the massive door
was closing!

I snatched away my arm; in my left hand I held the electric torch,
and springing sharply about I directed the searching ray into the
black gap of the stairway. A yellow face, a malignant Oriental
face, came suddenly, fully, into view! Instantly I recognized it
for that of the man who had driven Hassan's car!

Acting upon the determination with which I had entered the Gate
House, I raised my revolver and fired straight between the evil
eyes! To the fact that I dropped my left hand in the act of
pulling the trigger with my right, and thus lost my mark, the
servant of Hassan of Aleppo owed his escape. I missed him. He
uttered a shrill cry of fear and went racing up the wooden stair.
I followed him with the light and fired twice at the retreating
figure. I heard him stumble and a second time cry out. But,
though I doubt not he was hit, he recovered himself, for I heard
his tread in the corridor above.

Propping wide the door with my foot, I turned to Carneta. Her
face was drawn and haggard; but her mouth set in a sort of grim
determination.

"Earl is dea