something else I've been wondering
about. They charge one credit for this ride. Which makes a total of
about fifty credits for a capacity load--"

"I get you," Tom interrupted. "It costs at least two hundred credits in
fuel alone to get one of these chemical jalopies off the ground!"

Roger looked at Tom solemnly. "You know, Tom, I'd certainly like to know
what those guys are doing. You just don't hand out free rides in space."

"How about snooping around?" asked Astro.

Tom thought a moment. "O.K. You two stay here. I'll go aft and see what
they're doing."

Tom walked quickly to the stern of the ship, entered the power-deck
hatch, and disappeared. Astro and Roger, each taking one side of the
ship, strained for a look from the viewports. In a few minutes Tom
returned.

"Spot anything?" asked Roger.

"I'm not so sure," answered Tom. "They weren't on the power deck and the
cargo hatch was locked. I looked out the stern viewport, but all I could
see was a thick black cloud."

"Well, that's no help," said Roger. Suddenly the blond cadet snapped his
fingers. "Tom, I'll bet they're smugglers!"

"What?" asked Tom.

"That's it," said Roger. "I'll bet that's it. The concession is just a
phony to cover up their smuggling. It lets them take a load of stuff up
without a custom's search. Then, when they're far enough out--"

"They dump it," supplied Astro.

"Right!" agreed Tom finally. "What better place to hide something than
in space?"

"For someone else to pick up later!" added Roger triumphantly.

When Wallace and Simms returned, the three cadets were busy looking out
the viewports. And later, when the spaceship was letting down over the
exposition grounds, Tom commented on the ease with which the ship made
her approach for a touchdown.

"Roger," asked Tom quietly, "notice how she's handling now?"

"How do you mean?" asked Roger.

"Going out," said Tom, "she wallowed like an old tub filled with junk.
Now, while she's no feather, there's a big difference in the way she's
maneuvering!"

"Then they did dump something in space!" said Roger.

"I'm sure of it!" said Tom. "And from now on, we're going to keep our
eyes open and find out what it is!"

CHAPTER 4

Tom glanced at the astral chronometer over the control board of the
_Polaris_ and sighed with relief. It was nine P.M. He turned to the
intercom.

"Attention, please! Attention, please! The exhibit is now closing for
the night. All visitors w