have broken down, he turned
inquiringly to Captain Strong, but received only a blank stare in
return. Tom hesitated for a split second, then turned back to the
controls. He quickly flipped the teleceiver button on and began plotting
the course of the approaching asteroid, ignoring for the moment his
other duties on the control deck. When he had finished, he gave the
course shift to the power deck and ordered a blast on the starboard jet.
He waited for the course change, saw it register on the gauges in front
of him, then continued his work.

Strong suddenly leaned over and clapped him on the back
enthusiastically.

"Good work, Corbett. That broken recording was put there intentionally
to trap you. Not one cadet in twenty would have had the presence of mind
you showed in plotting the course of that asteroid yourself."

"Thank you, sir," stammered Tom.

"That's all--the test is over. Return to your quarters." He came over
and laid a hand on Tom's shoulder. "And don't worry, Corbett. While it
isn't customary to tell a cadet, I think you deserve it. You've passed
with a perfect score!"

"I have, sir? You mean--_I really passed?_"

"Next step is Manning," said Strong. "You've done as much as one cadet
can do."

"Thank you, sir"--Tom could only repeat it over and over--"thank you,
sir--thank you."

Dazed, he saluted his superior and turned to the door. Two hours in the
pilot's chair had made him dizzy. But he was happy.

Five minutes later he slammed back the sliding door and entered the
quarters of 42-D with a lusty shout.

"Meet Space Cadet Corbett--an Earthworm who's just passed his
control-deck manual operations exam!"

Astro looked up from a book of tables on astrogation and gave Tom a wan
smile.

"Congratulations, Tom," he said, and turned back to his book, adding
bitterly, "but if I don't get these tables down by this afternoon for my
power-deck manual, you're sunk."

"Say--what's going on here?" asked Tom. "Where's Roger? Didn't he help
you with them?"

"He left. Said he had to see someone before taking his radar-bridge
manual. He helped me a little. But when I'd ask him a question, he'd
just rattle the answer off so fast--well, I just couldn't follow him."

Suddenly slamming the book shut, he got up. "Me and these tables"--he
indicated the book--"just don't mix!"

"What's the trouble?"

"Ah--I can get the easy ones about astrogation. They're simple. But it's
the ones where I have to _combine_