n for emergency leave, sir, commencing now."

[Illustration]

"Permission denied!" said Walters. "This is exactly what I've been
talking about, Steve. You want to leave to go to Mars and look for Tom
when we need you here on the project."

Strong's face suddenly turned white. And then, for the first time in his
career, he ignored military courtesy and turned to leave without the
courtesy of a salute or permission to do so. Connel almost called him
back, but Commander Walters put a restraining hand on the major's arm.

"Think of it this way, Lou," he said. "If you wanted something you
believed to be right, and it was denied you, how would you feel?"

"I'd very likely do the same thing," snapped the major. "And I'd get my
rockets busted for it by my commanding officer!"

Walters grinned and pulled the major back to the desk where they
continued their discussion of the receivers on Mars.

They had no sooner begun their discussion when the sliding door opened
and Professor Hemmingwell burst into the room, his smock flying behind
him, his hair ruffled and eyes wide with fright.

"The ship! The ship!" he cried out. "Someone has blown up the whole
control panel of the ship!"

[Illustration]

CHAPTER 10

"It will take weeks to repair it!"

Professor Hemmingwell stood on the main deck of the giant spaceship
staring sadly at the mess of wires and tubes, controls and gauges,
switches and filaments, all shattered and useless.

"When did it happen?" demanded Connel.

"Less than half an hour ago," replied Dave Barret. "Professor
Hemmingwell and I were down at the far end of the hangar. The men had
just left for the day and we were planning the work for tomorrow."

"Then what happened?" demanded Connel. "Wait, don't answer yet!" He
stopped himself and turned to a Space Marine standing nearby. "You! Can
you work an audio recorder?"

"Yes, sir," replied the Marine.

"Then get a machine up here on the double and take down everything
that's said."

"Yes, sir," said the Marine and left the ship. Connel silently began
inspecting the wreckage. It was ten times as serious as the first
sabotage attempt.

Barret, Commander Walters, Professor Hemmingwell, and Captain Strong
watched the major, their teeth clenched, eyes clouded with anger. Where
the destruction of the first unit could have been called an accident,
here was tangible evidence of a deliberate attempt to stop the whole
project. The Space Marine, accom