He raised his head, sniffing the air. A thin sharp taint, reminiscent of stifling agony, told him they must be up and moving soon. The gas was diffusing but still dangerous; up yonder on the plateau, where it had been concentrated, it must have left nothing save desolation and death.... Only then did he become aware, with a start of amazement, of the great silence that enfolded mountain, sky, and desert. The air, at least, which had snarled with motors not twenty minutes earlier, should still have echoed to the sound of battle. But the sky was empty. No, not empty--abruptly landing lights cut a brilliant swathe far out on the desert. The buzzard pilot saw he had misjudged his altitude and tried to pull up, the huge ship stalled and its lights went out as it plowed into the ground. Before the sound of its crash reached the mountain's foot, a pillar of fire was mounting above the dunes, and they saw that the air was full of machines, attackers and defenders alike in one confused flitting swarm, wheeling, dipping and always drifting downward, unpowered. Ladna gasped, "What's happened? The buzzards--" "I don't know. Maybe your people--" "They're not my people any more," she interrupted swiftly. "Whatever you are, I am too.... And anyway, all the engines are dead." * * * * * Torcred got up stiffly. On the desert between them and the fire, an aero glided down, bounced and rolled to a shaky landing. Its pilot dropped to the ground and stood staring at his useless machine; he did not even look up as a buzzard passed low over him with a rush of wings, touched ground and slewed round a short way off with a broken landing gear. Small figures spilled out of it too, their movements expressing the same dazed lack of understanding. The enemies paid each other no heed. The smell of gas was stronger. The desert would be littered with aircraft, but they shouldn't have much trouble slipping through.... Still Torcred frowned, hesitating. He turned with sudden resolution to the girl. "Wait here. There's something I have to find out; but it won't take long." "No!" Ladna struggled to her feet. "I'll go with you." Torcred started to protest, then changed his mind. He turned silently toward the cliff whose blank stone face was lit redly by the dying fire, its great fissure a dark gulf of mystery. Inside the cleft it was pitchblack, but the footing was smooth, packed sand. Torcred felt his way between rock walls. At first he heard only the scufflings the girl made, groping behind him, and then he was conscious of a faint all-pervading hum. Something was humming deep in the rock, and Torcred felt sure now that he was going to find the meaning of the visions and of the battle's uncanny end.