"get up here and keep them apart!"

A guard stepped quickly between Tom and Connel, and the conversation
ended.

At the exit Connel and Tom stopped involuntarily at the sight before
them. Astro had entered the canyon near twilight, but the two spacemen
got a view of the Nationalists' base under the full noon sun. Connel
gasped and muttered a space oath. Tom turned halfway to his superior and
was starting to speak when both were shoved rudely ahead. "Keep moving,"
a guard growled.

As they walked, their eyes flicked over the canyon, alert for details.
Tom counted the ships arrayed neatly on the spaceport some distance
away, then counted others outside repair shops with men scurrying over
them like so many ants. Near the center of the canyon the bare trunk of
a giant teakwood soared skyward, a gigantic communications tower. Tom
scanned the revolving antenna, and from its shape and size deduced the
power and type of radar being used at the base. He admitted to himself
that the Nationalists had the latest and best. Connel was busy too,
noting buildings of identical design scattered around the canyon floor
that were too small to be spaceship hangars or storage depots. He
guessed that they were housings for vacuum-tube elevator shafts that led
to underground caves.

The canyon echoed with the splutter of arc welders, the slow banging of
iron workers, the cough and hissing of jet sleds, the roar of activity
that meant deadly danger to the Solar Alliance. Connel noticed as he
moved across the canyon floor that the workers were in good spirits. The
morale of the rebels, thought the space officer, was good! Too good!

At a momentary halt in their march, when Drifi stopped to speak with a
sentry, Tom and Connel found an opportunity to speak again.

"I've counted a dozen big converted freighters on the blast ramps, sir,"
whispered Tom hurriedly. "Three more being repaired, nearly finished,
and there are about fifty smaller ships, all heavily armed."

"That checks with my count, Tom," replied Connel hurriedly. "What do you
make of the radar?"

"At least as good as we have!"

"I thought so, too! If a Solar Guard squadron tried to attack this base
now, they'd be spotted and blasted out of space!"

"What about stores, sir?" asked Tom. "I didn't see anything like a
supply depot."

Connel told him of the small buildings which he believed housed the
elevator shafts to underground storerooms. "Only one thing is missing!"
he c