A FIENDISH MACHINE A chill of fear gripped Tom and his companions as they blinked helplessly in the glare! Had the enemy detected them the first moment they had set foot on Balala Island? Had they walked blindly into a trap? Gradually Tom's eyes and those of his friends adjusted to the dazzling radiance. A door, blocking the tunnel just ahead, had slid open and the light was pouring out of a room beyond. "What happened?" Arv gasped. Tom pointed downward to a pedallike plunger inserted in the tunnel floor. "This must be a switch," he explained. "When I stepped on it accidentally, it must have opened the door and flashed on the lights." Bud whistled. "Wow! Let's be thankful it wasn't a booby trap!" "Maybe it is," murmured Hank grimly. Steeling their nerves, and with every sense alert, the searchers advanced into the secret room. Tom suddenly gave a cry of amazement. "The earthquake machine!" A huge hydraulic device, with massive steel bed and supporting pillars, looking somewhat like the enormous body presses found in automobile plants, stood embedded in a recess in one wall. Tom rushed to the machine and examined it in 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.