a natural formation they could
not tell. The rock was rotten with perforations, through which air
flowed in a cool stream.

Jerry came softly to his feet to feel cautiously of the glowing,
luminous mounds along the wall. They were spread upon a ledge. The
light was cold to his touch, the material like fine soil in his hands.

"Fluorescent," whispered Winslow. "Calcium sulphide, possibly; I saw
them spreading it above ground in the sun. It absorbs light and gives
it off slowly." Jerry nodded; the source of the endless glowing lines
had been puzzling to him.

* * * * *

Their whispers ceased at a sound beyond a doorway. In the opening a
figure appeared, tall and erect, the figure of a girl. Her face was
white like the others of these whose lives were lived below the
surface, but there was a kindly softness in the eyes, a refinement and
intelligence of no low order, that contrasted with the cold eyes of
the warriors and the priests. Not beautiful, perhaps, by earth
standards, yet it required no straining of chivalry on Jerry's part to
find her human and lovely.

In silence the men stood staring. Then Foster, with unconscious
gentleness, made a revealing gesture. This woman--this girl--had saved
them. He knew it without words, and he was wordless to reply. He
dropped swiftly to his knees and pressed a bit of the golden robe
against his lips.

A flush of scarlet swept across the white face and receded. The hand
dropped from its startled poise and rested, gently, questioningly, on
the brown head bent before her.

She murmured unintelligible words in a guarded voice as Jerry arose.
"Marahna," she said, and touched her breast lightly. "Marahna." Her
head was erect, the whole attitude imperious, commanding. She
questioned them with swift, liquid words. The men shook their heads in
utter incomprehension.

Again she spoke, and again they shook their heads. Jerry felt foolish
and dumb. He took his turn at questioning, and this time, with a
trace of a smile, it was the girl's turn to shake her head. She had
mastered one sign at least.

Pointing toward the great hall they knew was somewhere above, she
reenacted the scene there; she evidently knew what had transpired. And
now Jerry nodded in confirmation. That she approved of the part they
had played was evident.

* * * * *

Now she questioned whence they had come. She pointed down, and her
fluttering hands