Rip wanted to ask why the big Planeteer was dubious, but he was too tired to phrase the question. He contented himself with watching the cruiser. In a short time the _Scorpius_ was balanced, with nose tubes counteracting the thrust of stern tubes, ready to flash into space again at a second's notice. Rip watched, puzzled. The cruiser was miles away. Why didn't it come any closer? Then suddenly it erupted a dozen fiery streaks. "Snapper-boats!" someone gasped. Rip jerked fully awake. In the ruddy glow of the fighting rockets' tubes, he had seen that the cruiser's missile ports were yawning wide, ready to spew forth their deadly nuclear charges in an instant. The snapper-boats flashed toward the asteroid in a group, sheered off, and broke formation. They came back in pairs, streaking space with the sparks of their exhausts. "Into the cave," Koa shouted. The Planeteers obeyed instantly. Koa took Rip's arm to lead him inside, but the young officer shook him off. "No, Koa. I'll take my chances out here. I want to see what they're up to." "Great Cosmos, sir! They'll go over this rock like Martian beetles. You'll get it, for sure." "Get inside," Rip ordered. He gathered strength enough to make his voice firm. "I'm staying here until I figure out some way to call them off. We can't just stand here and let them blast us. They're our own men." "Then I'm staying, too," Koa stated. A pair of snapper-boats flashed overhead and vanished below the horizon. Two more swept past from another direction. Rip watched, curious. What were they up to? Another pair quartered past them at high speed, then two more. The boats seemed to be crisscrossing the asteroid in a definite pattern. A pair streaked past, and something sped downward from one of them, trailing yellow flame. It exploded in a ball of molten fire that licked across the asteroid in waves. Rip tensed, then saw that the chemical would burn out before it reached them. "Fire bomb," Koa muttered. Rip nodded. He had recognized it. The Planeteers were trained in the use of fire bombs, tanks of chemicals that burned even in an airless world. They were equipped with simple jets for use in space. The snapper-boats drew off, back toward the _Scorpius_. Rip watched, searching for some reason for their actions. Then one of the boats pulled away from the others. It returned to the asteroid, with stern jet burning fitfully. "Is he landing?" Koa asked. Rip didn't know. The snapper-boat was moving slowly enough to make a landing. Directly above the asteroid it changed direction, circled, and returned over their heads. Rip could almost have picked it off with a pistol shot. Santos could have blasted it into space dust with one rocket. The snapper-boat changed direction, and for a fraction of a second stern and side tubes "fought" each other, making the boat yaw wildly. Then it straightened out on a new course. Koa exclaimed, "That's a drone!"