report to the control
tower for reassignment," snapped Strong. He turned and with a nod of
sympathy to Kit left the control deck.

"Let's go, Astro," sighed Tom. "We'll see you later, Kit. You too, Sid.
And--" They looked at each other, but there was nothing more that could
be said. The race was finished.

When Tom and Astro had finished packing their gear and left the ship,
Sid turned to Kit. "I'm going to take a look at the _Space Knight_!" he
announced.

"Better not, Sid." Barnard shook his head. "Miles is a rough customer.
He might not like visitors around his 'secret' on the power deck."

Sid's face was set. "I'm going," he repeated and ducked through the
hatch.

His face showing his disappointment at having lost the race, Kit paced
the deck for a moment and then he strode purposefully toward the hatch,
calling:

"Hey! Wait, Sid. I'm coming with you."

In the control tower at the far end of the spaceport, Tom and Astro
entered the station commander's office in time to overhear the last of
Commander Walters' orders to Captain Strong.

" ... might as well give the boys a rest before we begin our
investigations, Steve." He looked up as the door opened. "Oh, here they
are now."

"Cadets Corbett and Astro reporting, sir." Tom and Astro saluted
smartly.

"Stand easy, boys," said Walters, rising to face them. "I don't know how
much you've heard of this emergency on Titan, but you can be briefed on
details later. For the moment, all you have to know is that your
assignment here is concerned with a detailed checking-out of the whole
force-screen machinery. Take a twenty-four-hour rest and then report
back here ready for the hardest work you'll ever do in your lives."

"Yes, sir," said Tom.

"Where is Manning? Didn't he think it necessary to report to me?"
Walters looked at Strong. "Well, Steve? It's your unit?"

"It seems he got off the _Space Knight_ at Ganymede, sir," replied
Strong reluctantly. "Captain Miles said the last he saw of Manning he
was walking toward the deep-space section of the spaceport."

Walters' eyes suddenly became very bright and hard. "He got off, did he?
Well," he snapped, "this is just about the end of the line for Cadet
Roger Manning!"

"I'm sure Roger has a good explanation, sir--" began Tom.

Walters glared at the cadet. "None of that, Corbett. Manning is a bad
rocket and the sooner I get rid of him the better off the Academy and
the _Polaris_ unit will be. Now take your tw