O'Brine had been on his way to Terra, to see his family for the first
time in four years, when the cruiser's orders were changed. To the
commander, whose assignments had been made necessary by the needs of the
Special Order Squadrons, it was too much. So he took his disappointment
out on the nearest Planeteer, who happened to be Rip.

"The gases go through tubes," O'Brine went on. "A little nuclear material
also leaks into the tubes. The tubes get coated with carbon, Foster.
They also get coated with nuclear fuel. We use thorium. Thorium is
radioactive. I won't give you a lecture on radioactivity, Foster. But
thorium mostly gives off the kind of radiation known as alpha particles.
Alpha is not dangerous unless breathed or eaten. It won't go through
clothes or skin. But when mixed with fine carbon, thorium alpha
contamination makes a mess. It's a dirty mess, Foster--so dirty that
I don't want my spacemen to fool with it.

"I want you to take care of it instead--you and your men. The deputy
commander will assign you to a squad room. Settle in, then draw equipment
from the supply room and get going. When I want to talk to you again,
I'll call for you. Now blast off, Lieutenant, and rake that radiation.
Rake it clean."

Rip forced a bright and friendly smile. "Yes, sir," he said sweetly.
"We'll rake it so clean you can see your face in it, sir." He paused,
then added politely. "If you don't mind looking at your face, sir--to see
how clean the tubes are, I mean."

Rip turned and got out of there.

Koa was waiting in the passageway outside. Rip told him what had