While he waited, Gene poured a steady fire at the abhorrent foe. Still, not a gap showed in that long, undulating line. The moment one creature fell, another rushed in to take his place. Kac returned shortly, carrying the big skin sack of oil. "This is all we have," he apologized. "The plants that produce this are scarce, and so we never have a very large supply." "We can only hope it will be enough," Gene said grimly, taking the sack. "Here, give me your spear." Kac turned over the long shaft and the biologist quickly poured oil over it. Then he inserted the shaft of the slippery weapon in the leatherlike carrying strap of the sack. While doing this, a torch fell at his side in a burst of sparks and he snatched it up, smiling. "Thanks, sucker! I'll be returning the favor shortly! Now, Kac, here's what you must do: Take the torch and when I give the signal, touch it to the oilsack. Then stand away in a hurry. That clear?" Kac grinned in quick understanding of Gene's plan and enthusiastically prepared for his part in it. He crouched low, smoking firebrand ready in his hand, while Gene climbed to his feet and hoisted the odd ensemble over his shoulder. Gauging distance, he adjusted the angle of the spear, then took a firm stance. "Let 'er rip!" Kac leaped up and thrust the torch against the saturated sack, then threw himself to the ground and rolled frantically away. The bag blazed up instantly, and just as swift did Gene whip the spear up and forward. The roaring ball of fire left the shaft in a high arc, sailing straight toward the unsuspecting Beast People. Down it came, bursting at the feet of the nearest half-men. Flaming oil spewed over everything within a wide radius. It ate away flesh and hair with a voracity that was dreadful to see. Living torches raced madly about in circles, screaming at the top of their voices--then to collapse in smouldering heaps, the evil life within them fled before the cleansing flame. All along the line, creatures stopped dead in their tracks, an unreasoning fear striking deep in their hearts, if hearts they had. They could not see the cause of disaster, but they could hear its roar and the shrieks of their dying fellows. To them, it was as if a raging holocaust had leaped from the bowels of the earth to gulp them in. Then, as once before, the Beast People gave up to panic, and the solid ranks suddenly disintegrated. Pell-mell they fled, back into and across the valley, putting distance between themselves and the horror that supposedly pursued them. A jubilant shout went up from the defenders of the city: "The accursed ones are beaten! The man from Earth has this day given us final victory! Hail the man from Earth--our brother!"