As we neared it we suddenly stopped as if we had been stricken with instantaneous paralysis. Out of the door floated, on the soft night air, the sweetest music to which I have ever listened. It carried me back in an instant to my own world. It was the music of the earth. It was the melodious expression of a human soul. It thrilled us both to the heart's core. "My God!" exclaimed Colonel Smith. "What can that be? Are we dreaming, or where in heaven's name are we?" Still the enchanting harmony floated out upon the air. What the instrument was I could not tell, but the sound seemed more nearly to resemble that of a violin than anything else of which I could think. When we first heard it the strains were gentle, sweet, caressing and full of an infinite depth of feeling, but in a little while its tone changed, and it became a magnificent march, throbbing upon the air in stirring notes that set our hearts beating in unison with its stride and inspiring in us a courage that we had not felt before. Then it drifted into a wild fantasia, still inexpressibly sweet, and from that changed again into a requiem or lament, whose mellifluous tide of harmony swept our thoughts back again to the earth. "I can endure this no longer," I said. "I must see who it is that makes that music. It is the product of a human heart and must come from the touch of human fingers." We carefully shifted our position until we stood in the blaze of light that poured out of the door. The doorway was an immense arched opening, magnificently ornamented, rising to a height of, I should say, not less than twenty or twenty-five feet and broad in proportion. The door itself stood widely open and it, together with all of its fittings and surroundings, was composed of the same beautiful red metal. Stepping out a little way into the light I could see within the door an immense apartment, glittering on all sides with metallic ornaments and gems and lighted from the center by a great chandelier of electric candles. In the middle of the great floor, holding the instrument delicately poised, and still awaking its ravishing voice, stood a figure, the sight of which almost stopped my breath. It was a slender sylph of a girl! A girl of my own race; a human being here upon the planet Mars! [Illustration: _"In the middle of the great floor, holding the instrument delicately poised, and still awaking its ravishing voice, stood a figure, the sight of which almost stopped my breath! It was a slender sylph of a girl! A girl of my own race; a human being here on Mars!"_] Her hair was loosely coiled and she was attired in graceful white drapery. "By God!" cried Colonel Smith, "she's human!" CHAPTER TWELVE _RETREAT TO DEIMOS_ Still the Bewildering Strains of the music came to our ears, and yet we stood there unperceived, though in the full glare of the chandelier.