see this fellow messing around, Sid?"

Sid thought a moment and then his face clouded. "Come to think of it, I
saw him on the portside."

"I wasn't even close to the tanks!" exclaimed Astro.

"There was someone messing around them, then," said Roger.

"Yes," said Tom grimly. "But we don't know _who_--or _what_ he did."

"From the sound of those rockets," said Astro, "Kit's feeders are
clogged, or there's something in his reactant that the strainers are not
filtering out."

"Well," sighed Roger, "there isn't anything Kit can do but keep going
and hope that everything turns out for the best."

"_If_ he can keep going!" said Tom. "You know, there are some things
about this whole race that really puzzle me."

"What?" asked Roger.

"Impure reactant in Kit's ship, after fellows like Kit, Astro, and Sid
checked it a hundred times. Gigi Duarte crashing after making record
speed to the Moon. The minimum specifications being stolen from
Commander Walters...." Tom stopped and looked at his friends. "That
enough?"

Roger, Astro, and Sid considered the young cadet's words. The picture
Tom presented had many curious sides and no one had the slightest idea
of how to go beyond speculation and find proof!

[Illustration]

CHAPTER 6

"The winners are--" Captain Strong's voice rang loud and clear over the
loud-speakers--"first place, Captain Sticoon, piloting the Marsopolis
Limited entry, _Space Lance_! Second place, Captain Miles, piloting the
Charles Brett Company entry, _Space Knight_! Third place, Captain
Barnard, piloting his own ship, _Good Company_!"

There was a tremendous roar from the crowd. In front of the official
stand, Tom, Roger, and Astro pounded Sid Goldberg on the back until he
begged for mercy. On the stand, Strong and Kit shook hands and grinned
at each other. And Commander Walters stepped up to congratulate the
three winners. Walters handed each of them a personal message of good
wishes from the Solar Council, and then, over the public-address system,
made a short speech to the pilots of the losing ships thanking them for
their co-operation and good sportsmanship. He paused, and in a voice
hushed with emotion, offered a short prayer in memory of Gigi Duarte.
The entire spaceport was quiet for two minutes without prompting,
voluntarily paying homage to the brave spaceman.

After Walters left and the ceremonies were over, the three winners stood
looking at each other, sizing up one another. Ea