The droning hum of the helicopter came across the broken ground. Now louder, now momentarily muted, its moments of loudness grew steadily more strong. It was coming nearer. Thorn gripped his spear in an instinctive, utterly futile gesture of defense. Sylva touched his hand. "We'd better hide." They hid. Thick brush concealed them utterly. The helicopter went slowly overhead, and they saw Kreynborg gazing down at the earth below him. Nearly overhead he paused. And suddenly Thorn groaned under his breath. "It's the flagship!" he whispered hoarsely to Sylva. "Oh, what fools we were! The flagship! He knows the General would have brought it to earth opposite us, to question us!" * * * * * The flagship was nearly opposite. To find the flagship was more or less to find where Thorn and Sylva hid. But they had not realized it until now. The speaker in the helicopter boomed above their heads. "Ah, my friends! I think you hear me. Answer me. I haff an offer to make." Shivering, Sylva pressed close to Thorn. "Der Com-Pub fleet is on der way," said Kreynborg, chuckling. "Sefen-eights of der United Nations fleet is just outside. You haff observed it. In six hours der Com-Pub fleet begins der conquest of der country and der execution of persons most antagonistic to our regime. But I haff still weary weeks of keeping der air fleet prisoner, until its personnel iss too weak from starfation to offer resistance to our soldiers. So I make der offer. Come and while away der weary hours for me, and I except you both from der executions I shall findt it necessary to decree. Refuse, and I get you anyhow, and you will regret your refusal fery much." Thorn's teeth ground together. Sylva pressed close to him. "Don't let him get me, Thorn," she panted hysterically. "Don't let him get me...." * * * * * The droning, monotonous hum of the helicopter over their heads continued. The little flying-machine was motionless. The air was still. There was no other sound in the world. Silence, save for the droning hum of the helicopter. Then something dropped. It went off with an inadequate sort of an explosion and a cloud of misty white vapor reared upward on a hillside and began to settle slowly, spreading out.... The helicopter moved and other things dropped, making a pattern.... "The air's still," said Thorn quite grimly. "That stuff seems to be heavier than air. It's flowing downhill, toward the dome-wall. It will be here in five minutes. We've got to move." Sylva seemed to be stricken with terror. He helped her to her feet. They began to move toward higher ground. They moved with infinite caution. In the utter silence of this inner dome, even the rustling of a leaf might betray them.