The Skygors were ill-cultured, poor of spirit, prospered chiefly by ideas stolen from the human beings they enslaved. But they understood sound waves, could use them roughly as an electrician might use electric vibrations. There were all the tales he had heard, of a chord on the organ that shattered window panes, of certain orators who could employ voice-frequencies to spellbind and impassion their audiences. This was something like that, only more so.
Then he saw that Mara, who had thought of saving his ears, was down at his feet.
“Mara!” he cried, though nobody could have heard him. He knelt, ripping away more rags of his shirt. He crammed them furiously into her ears. She stirred, got to her knees. She, too, could endure it now, and she smiled at him, drawnly.
“I knew you would come back,” her lips formed words. “David Planter—my David Planter—”
Then she was up, crossbow at the ready.
Because back came the Skygors, a wave of them in boats and as swimmers. Sure of their victory through sound, they were going to mop up the attackers.
Max had a rifle. He lifted it, but on inspiration Planter leaped at him and gestured for him to hold fire. From beside one of the fallen Terrestrials he caught a grenade thrower. It was a simple amplification of an ordinary rifle. Upon the muzzle fitted a metal device like a bottomless bottle, the neck clamping tight to the barrel. Into the spread body of the bottle could be slid a cylindrical grenade, the size and shape of a condensed-milk tin. The grenade was pierced with a hole, and the gun, if fired, would send its bullet through that hole, while the gases of the exploding powder operated to hurl the grenade far and forcefully and accurately.
Planter had never used one, but he had seen them used. A quick check showed him that the rifle’s magazine was full. From the belt of the fallen man he twitched a grenade, slipped it into place. He knelt, placed the rifle butt on the soggy mass of rotting vegetation that made up the shoreside jungle floor. By guess, he slanted his weapon about forty-five degrees forward. The foremost press of Skygors approached.
Bang! At Planter’s trigger-touch, the grenade rose upward. For a moment the three conscious watchers could see it, outlined against the upper mists at the hesitating apex of its flight. Then it fell, too far to demoralize the first ranks of Skygors, but smashing two inflated boats in its explosion and tossing several slimy-green forms like chips through the air. Planter slid in another grenade, worked the rifle-bolt, and raised the weapon to his shoulder.
It spoke again, louder even than the din of the noisemaker Mara called the “spell.” This time it struck water among the leading Skygors, and exploded on contact. Three or four sank abruptly, several more thrashed the water into pinky-red foam in the pain of bad wounds, the rest wavered.
Now Max opened fire with his rifle, and Mara with her crossbow. Both scored hits, and the Skygors gave back. Something was going wrong, they were realizing. The destroying sound was not paralyzing their enemy. Meanwhile, it was best to take cover. Some ducked under the water, others fell back toward the buildings.
“Dynamite ’em!” cried Planter, forgetting that he could not be heard. Stooping, he stripped away the whole beltful of grenades from its helpless owner. He whirled it around his head as though he were throwing a hammer on an athletic field, and sent it flying out over the water. The shock of its fall into the depths set it off—all grenades at once. Skygors came bounding to the top, twitching feebly. The explosion had destroyed them, as fish are destroyed by the shock of detonating dynamite in nearby waters.
Then the paralyzing noise stopped.
Hommerson was the first man up. He was dazed and groggy, but fight was the first impulse that woke in him. Mara, Max and Planter dragged others to their feet, shook and shouted their senses back into them.
“They’re retreating!” Planter yelled. “Let’s counterattack!”
Close in to shore drifted one of the abandoned boats. Max had run into the water, dragging it closer. The Terrestrials tumbled aboard, and one of them got the paddle-wheel running. Planter, at the bow directing fire at any Skygors who showed their heads, saw that Mara had not come along. He worried a moment, then worried no more. She was shouting in the jungle, and other voices—feminine voices—answered her. More of the crossbow-girls were coming to help.
The boat made a landing at the building where Planter had first been dragged to slavery. It was not made for defense, and the invaders split into small parties, ranging the corridors and outer bridges. Planter, hurrying downstairs, heard the spat of the Skygor pen-missiles, with the replying crackle of gunfire. After a while, Mara and other girls began to shout and chatter. They had also found a boat and had come over.
On the floor, above the basement where the slaves worked, he came face to face with a Skygor, who lifted his arms appealingly, in the surrender gesture that must be universal among all creatures who have arms. “I want no fight,” begged this one. “You are master.”
“Then come downstairs,” snapped Planter. He clattered down, among the slaves. “Stop work!” he bawled, almost as loudly as a Skygor, and the men, bred to obey big voices, did so.
“Outside!” was Planter’s next command. One or two moved to obey, others hung back.
“Outside,” the surrendered Skygor echoed Planter, and they came obediently. Planter hurried them to their quarters, then slammed the door to the big workshop.
“That closes down your power plants,” he commented to the Skygor. “Now, quick! Which way to the controls of the dam?”
“Dam?”
