nde. To one side of the room,
lead sheets lined a rough boxlike structure that Astro and Tom guessed
was covering for the radioactive vein. Against the wall lay the
lead-lined suits used by the miners. Further to one side, Tom saw a
huge open pipe. He nudged Astro.

"Look, over there," Tom whispered. "That's where the oxygen is coming
from!"

Below them, Miles suddenly walked to the pipe and pulled a large lever
on its side. The roaring sound stopped immediately and the boys felt the
air pressure in the room lessen slightly.

"That blasted noise is driving me crazy," explained Miles, walking back
to the table, his voice echoing in the rock-walled cavern.

Brett, leaning over the table, was stabbing around futilely in one of
the sets of tubes in a complicated testing device. "Wish we had that
squirt Manning here," he mumbled. "He could fix these things up in no
time at all."

"I could always go back to the hide-out and get him," suggested Miles.

On the balcony Tom gripped Astro's arm tightly.

"Astro! Did you hear that?" he exclaimed.

The big cadet nodded and started to rise from their place of
concealment. Tom pulled him down. "Wait," he whispered sharply. "No use
barging in on them yet. Maybe we can find out where Roger is first."

Astro reluctantly crouched down again, his hamlike hands balled into
fists.

The two cadets watched Quent Miles and Brett work on the instruments
awhile longer. Finally Miles slammed down a pair of wire cutters on the
table and growled at Brett. "No use messing with this thing any longer.
I don't know what makes it tick, so I can't find the trouble. We need
new equipment."

"It'll take at least two weeks to get new equipment the way things are
going here at Titan," replied Brett.

"Well, there's no use hanging around here if we can't dig any more of
the stuff out, and I ain't going behind that lead shield unless I got a
machine that tells me it's safe."

"I've been thinking about Manning," said Brett.

"What about him?"

"Suppose we move the stuff we've already mined to the hide-out, and take
this equipment along too. He can repair it out there. We can turn off
the oxygen that we're sucking off from the Solar Guard pumps, and by the
time we get back here, the old satellite will be back to normal. Then,
with the equipment repaired and Olympia back to normal, we can really
begin operations."

Quent nodded quickly. "Good idea. Come on. Let's get this stuff aboard
the shi