Connel recognized as Tom's, boomed out over the loud-speaker of
the large jet ship near the edge of the clearing. "Now hear this! You
are covered by an atomic mortar. Drop your guns and raise your hands!"

The men stared at the ship, confused, but Hilmarc issued a curt command.
"Return to the ships!"

"But--but he'll blast us," whined one of the men. "He'll kill us all."

"You fool!" roared Hilmarc. "It must be a friend of Connel's or
Sinclair's. He won't dare fire an atomic shell near this house, for fear
of killing his friends! Now get aboard your ships and blast off!"

From their ship, Tom, Roger, and Astro saw the men scatter across the
field, and realizing their bluff had failed, they opened fire with the
paralo-ray guns. But their range was too far. In a few moments the
clearing around the Sinclair home was alive with the coughing roar of
the jets blasting off.

As soon as they were alone, Sinclair snatched up an abandoned ray gun
and released the major from the charge. Connel immediately jumped for
another gun. But then, as the jets started to take off, he saw that it
would be useless to pursue the invaders. Thankful that the cadets had
arrived in time, he trotted across the clearing to meet them as they
climbed wearily from the remaining jet ship.

"By the craters of Luna," he roared good-naturedly, "you three
space-brained idiots had me scared! I thought you would really let go
with that mortar!"

Tom and Roger grinned, relieved to find the spaceman unhurt, while
Astro looked off at the disappearing fleet of ships.

"What's happened, sir?" asked Tom. "What's it all about?"

"Haven't time to explain now," said Connel. "I just want you three to
know you got back here in time to save the rest of this man's property."
He turned toward Sinclair, who was just approaching. "Did you recognize
any of them?" he asked the planter.

Sinclair shook his head. "I thought I did--by their voices, I mean. But
I couldn't see anyone through that frosted headgear they were wearing."

"Well, they left a ship. We'll find out who that belongs to," said
Connel. "All right, Corbett, Manning, Astro. Stand by to blast off!"

"Blast off?" exclaimed Roger. "But we're on leave, sir!"

[Illustration]

"Not any more, you're not!" snapped Connel. "You're recalled as of now!
Get this ship ready to blast off for Venusport in five minutes!"

CHAPTER 8

"Are you sure they went south, Astro?"

Major Connel was examining a