fascination. A powerful
diesel generator stood nearby with banks of complicated electrical
equipment, amid a spider-web tangle of wiring. Tom assumed this gear was
for timing and synchronizing the shock waves. Evidently the whole setup
was operated from a single control panel in the wall, studded with knobs
and dials.

"What a job of design!" Tom exclaimed in awe. His eyes roved over every
detail of the equipment while he poked here and there with his hands. He
was getting the "feel" of the setup almost as much by touch and handling
as by his superb technical intuition. "Boy, I hate to admire anything
those Brungarian rebel scientists do, but this is really masterful!"

"Yes? Well, don't go ga-ga over it," said Bud. "Let's do what we came to
do and scram out of here. This place makes me jumpy!"

Tom appeared oblivious. "It seems like vandalism to wreck such an
engineering achievement! Also, and this may sound strange to you," he
went on in a doubtful tone, "are we _really_ justified in taking the law
into our own hands?"

"They're trying to wreck _our_ setup, aren't they?" Bud retorted. "Think
of the destruction they've caused already! Do you want to stand by and
see Enterprises destroyed too?"

"Bud's right," Hank Sterling spoke up quietly. "Take a look at this."

He beckoned them over to another corner of the cave and pointed to a
series of notations, crudely scrawled in white chalk on the cave wall.
Half hidden behind a clump of rock, they would have escaped casual
notice.

Tom read them and gave an angry gasp. A list of places and dates,
already checked off, showed the quakes that had occurred so far. The
last notation, not yet checked, said: SWIFT ENTERPRISES and was dated
five days ahead.

"Okay, that's all the convincing I need!" Tom said grimly.

He issued quick orders. Hank and Arv were to rush back to the _Sea
Hound_, get an underwater pump from the gear carried aboard, and install
it just off the beach. From there, they were to run a pipe line up into
the cave, using special plastic tubing which hooked together in a jiffy.

"Cover the piping with sand and gravel, so it won't be noticed," Tom
added. "In the meantime, Bud and I will go to work on this setup here."

"Aye-aye, skipper!" Hank and Arv responded.

As they hurried out through the tunnel, Tom and Bud set to work with the
tools they had brought along. The diesel was partly dismantled, sand
poured into its fuel feed, and the generator win