deserted plain several miles away from Space Academy. Then, one morning,
nearly a thousand construction workers arrived and built a hangar in
thirty-six hours. No sooner had the huge building been completed than a
tight guard had been placed around it. Specially designed
identification tags were issued to the guards and workers on the
project. Gradually the huge store of cases and boxes outside the hangar
had been moved inside, with all but a few of the smaller ones remaining
outside. The secret work inside the hangar was advancing rapidly, but
this did not enter into the thoughts of the three cadets of the
_Polaris_ unit, nor of the _Capella_ unit. The harsh discipline
instituted by Tim Rush and the extra study necessary for the end-of-year
exams had forced the cadets into a round-the-clock struggle not only to
keep awake but to make the class promotion lists.

Roger paced off the required distance, wheeled smartly, and in so doing
came face to face with Astro, who was patrolling another side of the
hangar.

"I just saw Firehouse," said Astro quietly. "Did he catch you goofing?"

"Yeah," growled Roger. "I found a kitten and he walked up just as I was
holding it."

Astro grinned. "I wouldn't be surprised if that pocket-sized giant
didn't send that cat down there to tempt you."

"How's Tom?" asked Roger. Astro, in his patrol, came in contact with
both unit mates.

"Sleepy. He's having a tough time with that chapter on space law. He