in fitting it artificially to support life, had roughed
it into a sphere and pulverized quantities of the rock into soil. Here,
at the apex, was a ring of rough naked hills enclosing a pit into which
the sun could not look. Ling, catching up with Parr on the brow of the
circular range, pointed with his great club.

"Look like mouth of world," he hazarded. "Dark. Maybe world hungry--eat
us."

"Maybe," agreed Parr. The pit, about a hundred yards across and full of
shadow, looked forbidding enough to be a savage maw. Izak also came
alongside.

"Mouth?" he repeated after Ling. "Mmm! Look down. Men in there."

There was a movement, sure enough, and a flare of something--a torch of
punky wood. Izak was right. Men were inside this polar depression.

"Come on," said Parr at once, and began to scramble down the steep,
gloomy inner slope. Ling grimaced, but followed lest his companions
think him afraid. Ruba and Izak, who feared to be left behind, stayed
close to his heels.

The light of the torch flared more brightly. Parr could make out figures
in its glow--two of them. The torch itself was wedged in a crack of the
rock, and beneath its flame the couple seemed to tug and wrench at
something that gleamed darkly, like a great metal toadstool at the
bottom of the depression. So engrossed were the workers that they did
not notice Parr and his companions, and Parr, drawing near, had time to
recognize both.

One was Sadau, who would have remained his friend. The other was Varina
Pemberton. In the torchlight she looked browner and more vigorous than
when he had seen her last.

"What are you doing?" he called to them.

Abruptly they both snapped erect and looked toward him. Sadau seized the
torch and whirled it on high, shedding light. Varina Pemberton peered at
the newcomers.

"Oh," she said, "it's you. Parr. Well, get out of here."

Parr stood his ground, studying the toadstool-thing they had been
laboring over. It was a wheel-like disk of metal, set upon an axle that
sprouted from the floor of rock. By turning it, they could finish
opening a great rock-faced panel near by....

"Get out," repeated the girl, with a hard edge on her voice.

Parr felt himself grow angry. "Take it easy," he said. "Your crowd
booted me out, and I'm not under your rule any more. Neither can this be
said to be your country. We've as much right here as you."

"Four of us," added Ruba with threatening logic. "Two of you. Fight,
uh?"

"Par