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 dead!” she said, in a queer, toneless voice.  “He died trying to get—­that thing!  I will get it, and destroy it!”

Before I could detain her, even had I sought to do so, she stepped into the filthy water, struggled to recover her foothold, and sank above her waist into its sliminess.  Without hesitation she began to advance toward the niche which contained the slipper.  In the middle of the pool she stopped.

What memory it was which supplied the clue to the identity of that nauseating smell, heaven alone knows; but as the girl stopped and drew herself up rigidly—­then turned and leapt wildly back toward the door—­I knew what occasioned that sickly odour!

She screamed once, dreadfully—­shrilly—­a scream of agonizing fear that I can never forget.  Then, roughly I grasped her, for the need was urgent—­and dragged her out on to the floor beside me.  With her wet garments clinging to her limbs, she fell prostrate on the stones.

A yard from the brink the slimy water parted, and the yellow snout of a huge crocodile was raised above the surface!  The saurian eyes, hungrily malevolent, rose next to view!

The extremity of our danger found me suddenly cool.  As the thing drew its slimy body up out of the poor I waited.  The jaws were extended toward the prostrate body, were but inches removed from it, dripped their saliva upon the soddened skirt—­when I bent forward, and at a range of some ten inches emptied the remaining three loaded chambers of my revolver into the creature’s left eye!