et car
Strong had used a short time before, racing along the same smooth
highway toward the spaceport on the other side of the hills. Tom was
wedged in between Astro and Roger, his eyes straight ahead on the road.

"Where do we start first?" asked Roger.

"We've got to get a ship. The _Polaris_, if possible. We can't begin to
look for the professor without one. As soon as Vidac learns that we've
escaped, the whole satellite will be crawling with colonists and his
boys, looking for us."

[Illustration: _"We better take it easy, Astro," said Tom. "Turn off the
lights."_]

"Colonists!" cried Astro. "Why would they want to help him?"

"Vidac will think of something to convince them that we're dangerous
criminals," said Roger grimly. "Tom's right. We've got to get the
_Polaris_."

They were just leaving the crystal city behind them and winding through
the hill section surrounding the flat plain. Astro's handling of the jet
car was perfect as he took the curves in the road at full throttle. They
still had a long way to go to reach the spaceport that had been built on
the other side of the hills.

"You sure did a fine job of conversion on these jet boats," said Tom to
Astro. "This baby feels as though she was going to take off."

"I wish it was," said Roger, looking up at the hills on either side of
them. "It would be a lot easier to blast over these things than go
through them."

The car sped up to the last summit that separated them from the
spaceport.

"We'd better take it easy," said Tom. "Turn off the lights, Astro. We'll
ditch this jet car about a mile from the spaceport and walk the rest of
the way."

"Right," said Astro. He gunned the little vehicle for the last burst of
speed necessary to take them over the top. The jet car shuddered under
the extra power and a moment later the spaceport lay spread before them.
Below them, in a five-mile circle, they could see the few remaining
ships of the great fleet. The _Polaris_ was easily recognized, and
fortunately, was on the nearer side of the giant landing area.

"There's home," said Roger.

"Yes," agreed Tom. "And she sure looks good to me--"

The curly-haired cadet suddenly stopped as powerful headlights loomed on
the highway ahead.

"That's Vidac's jet car," said Roger. "I recognize the lights. We've got
to get out of here!"

Astro braked the small vehicle and it screamed to a stop. The three
cadets hastily piled out and raced for the darkness of the