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 i