Overcoming the fear and astonishment which momentarily had deprived me of action, I advanced with the utmost caution in the direction from whence this mysterious singing seemed to proceed. Passing an angle of the house, where the stucco wall ran sheerly up to a _mushrabîyeh_ window, I perceived before me a smaller, detached building in the form of a sort of pavilion. Some fine acacias overhung its white and glistening dome, in which were little windows of colored glass. Concealed in the shadow of the house, I stood looking towards this smaller building, observing with astonishment that it possessed a massive, bronze-mounted door. Indeed, in many respects, and in spite of the charming picture which its jeweled appearance presented, it might well have been the tomb of some holy Sheikh. But seated on an old-fashioned _mastabah_ before the entrance were two huge negroes of most ferocious aspect, armed with scimitars which glittered evilly in the light of the moon! I drew back sharply into the shelter of the projecting wall. One of the negroes seemed to slumber, but the wicked black eyes of his companion were widely open and he revealed his ivory teeth in a frightful leer. The beating of my heart almost suffocated me, for I ascribed that ghastly grimace to the fact that the negro had detected my presence and was already gloating over the pleasing prospect of my swift and bloody despatch. For many agonized moments I lurked there, one hand clutching the stucco wall and the other resting upon the butt of a new Colt magazine pistol which I had taken the precaution to purchase in Alexandria a week earlier. When again I ventured to protrude my head, I learned how groundless my fears had been; I realized that the loathsome contortion of the negro's countenance represented a smile of appreciation. He was listening to the unseen singer whose voice now stole again upon the silence of the night! His blubber lips drooped open cavernously and his fierce little eyes blinked in stupid rapture. It appeared to me, now, that the sweet voice proceeded from some subterranean place: I thought that I was listening to the song of a _ginneyeh_. I remembered how the Sheikh Ismail was reputed to be the son of an _Efreet_ and an Arabian princess, and to have lived in that oasis for generations, since the reign of the Sultan Mohammed Nâsir ibn-Kalaûn, who had expelled him from Cairo as a magician. He was said to possess the secrets of Geber and of Avicenna--the great Ibn Sina of Bokhara; to possess the Philosophers' Stone and the _Elixir Vitæ_. In this pavilion with the bronze door I beheld the magician's treasure-house, guarded, within, by a _ginneyeh_ and, without, by ghouls or black _Efreets_!