s happy, my little Loah-San," said Gor. His eyes held a puzzled
look. "Always until now. And now she weeps and will not say why. Come,
we will walk more slowly. There were questions you wished to ask. I
will answer them as we walk."

"Questions?" exclaimed Rawson. "A thousand of them."

* * * * *

And now for the first time since, at the top of a barren peak, in the
dark of the desert night, his wild journey had begun, he found
answers, definite and precise, to the puzzles he had been unable to
solve.

Their speech--their language--how was it they could talk with him? He
fired the questions out with furious eagerness, and Gor replied.

As to their speech--the Holy Mountain itself would explain. And yes,
truly, this was the center of the world, or the sun above them was.
The central sun did not attract, but instead repelled all matter from
it--all things but one, the sun-stone, of which Gor would speak
later.

Rawson pounced upon that and demanded corroboration.

"All the power of earth tends to draw every object to its center, yet
we're here on an inner surface. We're walking actually head down. And
our bodies, every stone, every particle of matter, ought by well-known
laws to fall into that flaming center. But we don't! That proves your
point--proves a counter gravitation. Then there must be a neutral
zone. A place where this upward thrust is exactly equalled by
gravity's downward pull.

"The zone of fire," said Gor. "You passed through it. Did you not
see?"

"Saw it and felt it!" Rawson's mind leaped immediately to the next
question.

"And we must have come through it at, surely, a thousand miles an
hour. What drove us? That shell must have gone in from here. I can
understand its falling one way, but not two. We should have come to
rest in that very spot--and we'd have lasted about half a second if we
had."

"Oro and Grah," said Gor. "Oro, the sun-stone, and Grah, the
stone-that-loves-the-dark. But they are not stones, neither are they
metal. We find them deep in the ground, clinging to the caves. A fine
powder, both of them."

"Still I don't get it," said Rawson. "You drive that shell in from
here, and then you drive it back again."

"That, too, I will explain later. It is simple; even the Dwellers in
the Dark--those whom you call the mole-men--have Oro and Grah to serve
them."

* * * * *

Gor launched into a long account of their tri