The man was shaking, his eyes looked wild. "They'll kill us. We've got to get out of here." "Wait, you fool. They may not even have seen us." But he was gone, running toward a group of ships lined up at the end of the cavern. "Who was that crazy coot and what is this place?" Brian demanded. "That was Gort Sterling, our leader," the girl said bitterly. "And this is our headquarters." One of the ships at the back of the cavern thundered to life, streaked across the floor and burst out through the opening Crystal's ship had left. "He hasn't got a chance! We'll be spotted for sure, now." The other rebels waited uncertainly, but not for long. There was the crescendoing roar of ships in a dive followed by the terrific crash of an explosion. "They got him!" Crystal's voice was a moan. "Oh, the fool, the fool!" "Sounded like more than one ship. They'll be after us, now. Is there any other way of getting out of this place?" "Not for ships. We'll have to walk and they'll follow us." "We've got to slow them down some way, then. I wonder how the devil they traced us? I thought we lost them in that fog." "It's that Serono Zeburzac, the traitor. He knows these mountains as well as we do." "How come?" "The Zeburzacs are one of the old families, but he sold out to McHague." "Well, what do we do now? Just stand here? It looks like everybody's leaving." "We might as well just wait," Crystal said hopelessly. "It won't do us any good to run out into the hills. Zeburzac and his men will follow." "We could slow them down some by swinging a couple of those ships around so their rocket exhausts sweep the entrance to the cavern," Brian suggested doubtfully. She looked at him steadily. "You sound like the only good rebel left. We can try it, anyway." * * * * * They ran two ships out into the middle of the cavern, gunned them around and jockeyed them into position--not a moment too soon. Half a dozen police showed in brief silhouette as they slipped cautiously into the cavern, guns ready, expecting resistance. They met a dead silence. A score or more followed them without any attempt at concealment. Then Brian and Crystal cut loose with the drives of the two ships. Startled screams of agony burst from the crowded group of police as they were caught in the annihilating cross fire of roaring flame. They crisped and twisted, cooked to scorched horrors before they fell. A burst of thick, greasy smoke rushed out of the cavern. Two of the police, their clothes and flesh scorched and flaming, plunged as shrieking, living torches down the mountainside. Crystal was white and shaking, her face set in a mask of horror, as she climbed blindly from her ship. "Let's get away! I can smell them burning," she shuddered and covered her face with her hands. Brian grabbed her and shook her. "Snap out of it," he barked. "That's no worse than shooting helpless men in parachutes. We can't go, yet; we're not finished here."