Limpy was sullen; the more the right side of his face drew down in anger, the more sardonically leered the frozen left side. Swede's placid features showed no emotion, but his clenched fists did. Mac alone tried to appear cheerful, though his mind was furiously analyzing their grave situation. While Birchall said nothing, peering absently into space.

Silently, the men pulled on steel-soled shoes, lead-fiber gloves and infra-red goggles. On their backs they strapped compact battery-radios with short antennae, a fixed microphone at the chest. The loudspeaker atop each small set, at neck level, could be heard in anything short of a vacuum or explosion. Then the defenders armed themselves with flame-throwers and machine guns that shot steel-piercing bomb bullets.

Straightening, Mac asked: "How many fishmen are staying?"

"Twenty-one," snarled Birchall.

Mac grinned wryly. "Cheer up, Al. That's better than I figured on." He turned. "Limpy, stay up at lookout. Warn me when the 'pedes are getting close. Swede, you and Al set up ammunition dumps in the compound. Then make sure the explosives and contacts will work fast if we have to blow up the place in a hurry."

While the others dispersed, Mac gathered a squad of fishmen, armed with flame-throwers and led them outside the high fence. Methodically, they burned down all vegetation for a distance of several hundred yards, to prevent the centaurpedes from creeping up close under cover.

When Mac and his detachment were returning, Limpy opened a sluice from the central control tower. Oil poured into the shallow water-filled moat that ringed the wire barrier. A thick, greasy film spread over the water.

Meanwhile, the rest of the fishmen had been deployed around the inside of the fence. They stood nervously holding their flame-throwers, their membrane-covered eyes bulging anxiously. Up on the stilt towers, the best native marksmen pressed their quivering scaled shoulders against the stocks of mounted machine-guns.

Mac felt a pang of gratitude. He knew what their decision to stay had meant. All life on Venus dreaded the centaurpede with a blind, wild terror.