In a short time the _Scorpius_ was balanced with nose tubes counteracting the thrust of stern tubes, ready to flash into s.p.a.ce 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 deadly nuclear charges.

The snapper-boats flashed toward the asteroid in a group, sheered off, and broke formation. They came back in pairs, streaking s.p.a.ce 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 dozen boats seemed to be criss-crossing the asteroid in a definite pattern. Why?

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 s.p.a.ce.

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 over 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 s.p.a.ce 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.

[Ill.u.s.tration: "They're Using Fire Bombs," Muttered Koa.]

"They're Using Fire Bombs," Muttered Koa.

Koa exclaimed, "That's a drone!"

Rip got it then. A pilotless snapper-boat! That's why its actions were a little uneven. Only one thing could explain its deliberate slowness. It was bait. The _Scorpius_ had sent piloted snapper-boats over the asteroid at high speed, criss-crossing in order to cover the thorium world completely, expecting to have the unknown rocketeer fire at them. Then a fire bomb had been dropped as a further means of getting the asteroid to fire. But no rockets had been fired from the asteroid, so the pilot in control of the drone had sent it at low speed, a perfect target.

That meant O'Brine wasn't sure of what was going on. He must have seen the blip on his screen as the Connie cruiser flamed off, Rip reasoned. But the commander probably suspected that the Connies had overcome the Planeteers and were in control of the asteroid. He had sent the snapper-boats to try and draw fire in an attempt to find out more surely whether Planeteers or Connies had the thorium rock.

"The _Scorpius_ doesn't know what's going on," Rip told his Planeteers.

"O'Brine didn't know the cruiser was waiting to ambush him, so the rocket we fired made him think the Connies had taken us over."

He put himself in O'Brine's place. What would his next step be? The snapper-boats hadn't drawn fire, even when a drone was sent over at low speed. The next thing would be to send a piloted boat over slowly enough to take a look.

Rip hoped O'Brine would hurry. There was no longer any feeling in his arm below Koa's safety line. That meant the arm had frozen. He had to get medical attention from the _Scorpius_ pretty soon.

He gritted his teeth. At least he was no longer losing blood. He wasn't getting any weaker. But every now and then his vision fogged and he had to shake his head to clear it.

The pilotless snapper-boat made another slow run, then put on speed and flashed back to the group of boats near the cruiser. Another boat detached itself from the squadron and moved toward the asteroid.

Rip wished for a communicator powerful enough to reach the _Scorpius_, but knew it was useless to try with his helmet circuit. The carrier waves of the snapper-boats were on the same frequency, and they would smother the faint signal from his bubble.

But the boats might be able to hear if they got close enough! He had a swift memory of the communications circuits. The pilots were plugged into their boat communicators. If a boat got near enough, he could turn up his bubble to full volume and yell. Not only would the boat pilot hear him, but his voice would go through the pilot's circuit and be heard in the ship!

Rip grabbed Koa's arm. "Let's move away from the cave a little farther."

The two of them stepped away from the cave and stood in full view as the snapper-boat moved cautiously down toward the asteroid. Rip planned what he would say. "Commander O'Brine, this is Foster!"

No, that wouldn't do. Connies would know that Kevin O'Brine commanded the _Scorpius_, and if they had taken over the Planeteers on the asteroid, they would also have learned Rip's name. He had to say something that would identify him beyond a doubt.

The snapper-boat was closing in slowly. Rip knew the pilot and gunner must be tense, frightened, ready to blast with their guns at the first wrong move on the asteroid. He groped with his good arm and turned up his helmet communicator to full volume.

The fighting rocket drew closer, cut in its nose tube, and hovered only a few hundred feet above the Planeteers.

Rip summoned enough strength to make his voice sharp and clear. His words sped through s.p.a.ce into the bubble of the pilot, echoed in the helmet and were picked up by the pilot's microphone, then hurled through the snapper-boat circuit through s.p.a.ce to the control room of the cruiser.

O'Brine stiffened as the speaker threw Rip's voice at him, amplified and hollow-sounding from reverberations in the boat pilot's helmet.

"_O'Brine is so ugly he won't look at his face in a clean blast tube! That no-good Irishman wouldn't know what to do with an asteroid if he had one!_"

The commander turned purple with rage. He bellowed, "Foster!"

A junior s.p.a.ce officer hid a grin and murmured, "Looks like the Planeteers still have the asteroid."

O'Brine bent over the communicator and yelled, "Deputy commander! Launch landing boats. Get those Planeteers and bring them here, under armed guard. Ram it!"

The snapper-boat pilot through whose circuit Rip had yelled turned to look wide-eyed at his gunner. "Did you hear that? Throw a light down on the asteroid. It must have come from there."

The gunner threw a switch and a searchlight port opened in the boat's belly. Its beam searched downward, swept past, then steadied on two s.p.a.ce-clad figures.

"It worked," Rip said tiredly. He closed his eyes to guard them against the brilliant glare, then waved his good arm.

Santos called from the cave entrance. "Sir, landing boats are being launched!"