t the
proper intervals to slow down the missile still further and bring it
back on beam."

The excited buzz of voices in the compartment gradually quieted as the
clock ticked steadily toward the next step in the recovery operation.

"Stand by for missile firing!" Tom snapped.

A seaman relayed the order over the ship's intercom. Tense silence fell
as Tom's eyes followed the sweep of the second hand.

"All clear for blast-off!" came the talker's report.

Tom pressed the firing button. A split second later the listeners'
eardrums throbbed to a muffled roar from topside as the slender recovery
missile shot skyward. The ship rocked convulsively from the shock of
blast-off. Then it steadied again as the gyros damped out the
vibrations.

"Wow!" Bud heaved a sigh of relieved tension. Then he dashed from the
compartment and up the nearest ladder for a quick look at the rocket as
it disappeared into the blue.

Tom watched the recovery missile intently on the radarscope.

"Nice going, son," said Mr. Swift quietly.

In response to his father's reassuring grip on his arm, Tom flashed him
a hasty smile. For the first time, the young inventor realized he was
beaded with perspiration and that his pulse was hammering.

"It's a case of wait and hope," Tom murmured.

[Illustration]

On every ship and plane in the task force, eyes were glued to the radar
screens. Two small blips were visible--one the Jupiter probe missile,
the other the recovery missile--moving on courses that would soon
intersect.

Just as Bud returned to the compartment, several of the watchers gave
startled gasps.

"Another blip--coming in from nine o'clock!" Admiral Walter exclaimed.
"What's that?"

Tom stared at the new blip. It was moving steadily toward the meeting
point of the first two missiles!

"It's a thief missile!" Tom cried out. "Some enemy's trying to steal our
probe data!"

"Good night!" Bud gulped. "Who'd dare try that?"

"I don't know," Tom muttered tensely. "But if those three missiles meet,
our whole project will be wrecked!"

"Better tape all readings!" Mr. Swift advised.

"Right, Dad!"

Admiral Walter had paled slightly under his deep tan. In stunned
silence, the Navy officers and scientists watched as Tom's lean hands
manipulated two controls.

"What are those for?" Bud asked.

"One's to speed up our recovery missile," Tom explained. "Looks like a
slim hope, though, from the way that third blip is homing on target.