HE HAD THE ANSWER AN instant later. Up on the wall a warning bell sounded and a red light flashed off and on. From a microtone speaker sounded that same deep-toned drone. Again it began to mount swiftly up the octaves, rising steadily to a high-pitched shriek preparing the way for the supersonic vibrations of the Hudrites. The lieutenant clapped his hands to his ears, fell to the floor in writhing agony.
Stabbing lancets of pain darted through his brain. He felt his eyes protruding; his head seemed ready to explode. With a mighty effort he managed to jerk on his dehydration mask, slide the protective ear-caps into place. Even then the sensation was only partly relieved, and he stood, heart pounding, waiting for the mad vibration to stop.
When at length it came to an end, a glance at the
