They did not spread out wide across the valley, but formed a straggling line that was denser toward the center. They could not know what opposition they would meet; for the present they would stay together. Above them as they came were twinkling lights of pale-green fire. The radio had spoken of heat rays; Rawson wondered if that meant some newer and more horrible instrument. But he saw nothing but the flame-throwers in the armament of this force. He was waiting by the irrigation pool, hidden for the moment behind the little knoll. Loah was with him; he had tried in vain to induce her to stay with Gor and the others who were waiting beyond the mountain. There were watchers, some of them within hearing, whose voices relayed the news of the enemy's advance. Then they ran; panic was upon them. "_Tur--gona!_" they cried, "_Nu--tur--gona!_ We die! Quickly we die!" Rawson heard the shout carried on toward the hidden throng. Cautiously he peered from the little knoll. They were coming. Already they were trampling the remaining red blooms on the farther edge of the field. But he waited till they were halfway across before he leaped to the top of the knoll, grasped a pole he had placed there in readiness and rammed it down through the pool, turbid yellow with the juice from the vines, and broke open the outlet he had plugged in the base. * * * * * One green light slashed above his head. One flicked at the knoll near his feet, where green growing things burst into flame--then he threw himself backward down the short rocky slope while the stones tore at his nearly nude body. He sprang to his feet and held Loah close. On either side of the knoll was a holocaust of flame where green lights played. He waited breathlessly. The fires brought in a little back draft of air, the scent of peach pits was strong--and then the green lights ceased. The unripe grain of the fields smoldered slowly. Then Rawson stepped from his hiding and stared out at the Place of Death. Nearby was a huddle of bodies. On either side, in a long, straggling line, they lay now on the ground--a windrow where Death had reaped. The flames of their weapons still in action were all that moved. The white earth turned molten wherever those flames struck. Farther off there were red things that were running. The yellow liquid from the pool, charged with the acid of the vines, had been slow in flowing out through that long trough. The savages could only see that their fellows had fallen. Some mystery, something invisible and beyond their comprehension had struck them. They ran toward the center at first, then turned and fled--and by then the soft air blowing gently about them had brought that strange fragrance of death. Then they, too, lay still. From the distance came faintly a booming chant, two thousand voices raised in unison. "_Tur--gona! Nu--tur--gona!_" The last of a once mighty people were marching to their death.