o Tom and Roger over a cup of
tea, "was about two years ago. I was bucking rockets on an old tub
called the _Space Plunger_. It was on a shuttle run from the Martian
south pole to Venusport, hauling vegetables. What a life! Burning up on
Venus and then freezing half to death at the south pole on Mars." Astro
shook his head as the vivid memory took him back for a moment.

"From what I hear," said Tom, "there isn't much to see but the few
cities, the mountains, the deserts and the canals."

"Yeah," commented Roger, "big deal! Rocket into the wild depths of space
and see the greatest hunk of wasteland in the universe!"

The three boys were silent, listening to the steady hum of the rockets,
driving them forward toward Mars. For four days they had traveled on the
_Lady Venus_, enjoying the many luxuries found on the passenger ship.
Now, with their destination only a few hours away, they were having a
light snack before making a touchdown on Mars.

"You know," said Tom quietly, "I've been thinking. As far back as the
twentieth century, Earthmen have wanted to get to Mars. And finally they
did. And what have they found? Nothing but a planet full of dry sand, a
few canals and dwarf mountains."

"That's exactly what I've been saying!" said Roger. "The only man who
ever got anything out of all this was the first man to make it to Mars
and return. He got the name, the glory, and a paragraph in a history
book! And after that, nothing!" He got up and climbed the ladder to the
radar deck, leaving Astro and Tom alone.

Suddenly the ship lurched to one side.

"What's that?" cried Tom.

A bell began to ring. Then another--and then three more. Finally the
entire ship was vibrating with the clanging of emergency bells.

Astro made a diving leap for the ladder leading down to the power deck,
with Tom lunging for the control board.

Quickly Tom glanced about the huge board with its many different gauges
and dials, searching for the one that would indicate the trouble. His
eye spotted a huge gauge. A small light beside it flashed off and on.
"By the moons of Jupiter, we've run out of reactant fuel!"

"Tom!--Tom!" shouted Astro from the power deck. "We're smack out of
reactant feed!"

"Isn't there any left at all?" asked Tom. "Not even enough to get us
into Marsopolis?"

"We haven't enough left to keep the generator going!" said Astro.
"Everything, including the lights and the teleceiver, will go any
minute!"

"Then we can'