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 windings 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.