ern vacuum-tube elevator shaft. He was pushed inside with the men of
the patrol and the tree-trunk door was closed. The leader pushed a lever
and the car dropped so suddenly that Astro nearly lost his balance. He
judged that they must have fallen two hundred feet when the car stopped
and another door opened. He was pushed out into a high-vaulted tunnel
with cement walls.

"Hurry up!" snapped the leader.

The big cadet moved along the tunnel, followed by the patrol, turning
from one tunnel into another, all of them slanting downhill. Astro
guessed that he was being taken to some subterranean cave. He asked his
captors where they were taking him.

"Don't talk!" snapped one of the men at his side.

"This jungle will be swarming with Solar Guardsmen once they discover
I'm lost," said Astro. "Who are you and what are you holding me prisoner
for?" The big cadet decided it would be better to feign ignorance of the
existence of the rebel organization.

"Let the Solar Guard come!" snapped the leader. "They'll find something
they never expected."

"But what do you want with _me_?" asked the cadet.

"You'll know soon enough!"

They had been walking for nearly an hour and the tunnels still slanted
downward but more sharply now. Turning into a much larger tunnel than
any of the rest, Astro noticed a huge door on one side. Through its
crystal-covered ports he saw racks of illegal heat blasters and
paralo-ray guns. A man stepped out of the door, and raising his hand in
a form of salute, called out a few words in the Venusian tongue. Astro
recognized it as a greeting, "Long live Venusians!" and suppressed a
smile.

One by one, the men of the patrol handed over their rifles and ray guns,
while the man in the armory checked off their names. Then they all
removed their knee-length jungle boots and traded their plastic helmets
for others of the same design but of a lighter material. Each man turned
his back while switching helmets, obviously to avoid being recognized by
any of the others, since the new helmet was also frosted except for a
slit at eye level. Wearing the lighter headgear and common street shoes,
the men continued their march through the tunnel. They passed into a
still larger tunnel, and for the first time, Astro could see daylight.
As they drew nearer to the mouth of the tunnel, the cadet could see
outside, and the scene before him made him gasp for breath.

A full twenty miles long and fifteen miles wide, a can