dings ripped out. The
boys then tore off and tangled all wiring leads to the electrical
equipment, took apart much of the equipment itself, and smashed the
control panel.

"Boy, if those Brungarian creeps get this setup working again, they're
_really_ geniuses!" Bud said as he and Tom paused a second.

"This is only the beginning, pal!" Tom said. "Let's tackle the machine!"

The huge earthquake device was a far more difficult proposition to
disable. Its heavy structural parts had to be disassembled or pried
apart, one by one. Both boys were streaked with sweat as they finished.

By this time, Hank and Arv had the piping installed halfway into the
tunnel. Spurred on as if by a sixth sense of danger, Tom told them to go
back to the beach and get the pump working while he and Bud connected
the few remaining pipe lengths into the machine room.

Minutes later, their job done, Tom and Bud rushed out to the mouth of
the cave and waved their flashlights. Soon the water could be heard
boiling through the pipeline. It gushed out with a roar, flooding the
machine room.

"Let's go!" Tom cried, yanking Bud's arm.

As they reached the beach and joined Hank and Arv, Tom's keen ears
picked up the drone of a plane somewhere in the darkness.

He gave a yell of alarm and pointed skyward. A ghostlike jet came
zooming into view, boring straight toward them. All four broke into a
mad dash for the seacopter.

They were halfway out on the reef when the plane leveled out of its dive
with an earsplitting whine.

"Hide!" Tom shouted, fearing a bomb might be dropped.

[Illustration
(Tom and friends are attacked by a ray gun from an airplane)]

All leaped for cover among the rocks. At the same instant, a fiery beam
like a bolt of lightning shot from the plane. It seared the spot on the
reef they had just vacated!

"A ray gun!" Bud gasped.

The plane's speed had already carried it far past the island. Before it
could maneuver around for another pass, Tom and his companions were on
their feet, racing for the safety of the _Sea Hound_.

They were aboard and clamping shut the hatch lid as the jet made its
second pass. This time its fiery ray glanced harmlessly off the
seacopter's Tomasite sheathing. Seconds later, the _Sea Hound_ had
darted off beyond reach into the ocean waters.

"Whew! We really broke all speed records that time!" Arv panted.

The others looked at him with wan but triumphant grins. Then they began
to specul