As Tom stepped out onto the surface of the asteroid he wasn't quite sure what he expected to see, but he certainly wasn't ready for the sight that greeted his eyes.

As far as he could see, there was gra.s.s, spotted with small one-story buildings. To the left was a single towering structure built of t.i.tan crystal and on top of it was the largest atomic blaster he had ever seen. He turned to ask the guardsman about the gun but was motioned ahead with a curt, "No questions. Keep walking."

Tom continued to walk. He noticed that they were heading for the tower.

As he drew nearer, he could see men walking around a narrow catwalk at the top. They all carried paralo-ray rifles with miniature grids mounted on the barrel. Inside the rifle was a tiny radar direction finder. It was a simple but effective control against escaping prisoners. Each of the inmates of the Rock wore small metal disks welded to a thin chain around their waists. The disk was sensitive to radar impulses, and with no more effort than snapping a thumb catch on the rifle, the guard could locate and paralyze the nearest disk-wearing inmate.

Tom was so full of questions it was necessary for the guard to warn him again, only this time in sharper tones.

Entering the tower, they were scrutinized and cleared by an electronic beam that pa.s.sed through their bodies and indicated any metal they might carry. Once through this last barrier, they were escorted to a slidestairs, where Williams left them.

Throughout the entire procedure few words had pa.s.sed between the cadets.

Now left alone on the stairs, they couldn't contain themselves and the comments and questions tumbled out.

"Did'ja see that blaster on top of this place?" Roger blurted out.

"Those radar-controlled paralo-ray rifles are really something!" said Astro.

"The thing I want to know," said Tom, "is where are the prisoners? I haven't seen one yet."

"And you're not likely to, either, Cadet Corbett!" said a gruff voice above them. They turned to see a heavy-set man wearing the uniform of a major in the Solar Guard, standing on the floor above them. The slidestairs carried them to his level and Captain Strong hopped off and extended his hand in greeting.

"Major Savage!" he explained. "Good to see you again!"

"Same here," said Savage, returning Strong's firm handclasp. He turned and faced the cadets. "So this is the _Polaris_ unit, eh?" He smiled.

"We've really enjoyed the stereo of that game of mercuryball you played back at the Academy."

"Thank you, sir," said Tom. "Lieutenant Williams has already told us how much he liked it."

"Come into my quarters and relax. I imagine you could do with some good solid food after those synthetics on your trip."

"We certainly could, sir," said Strong.

They followed the big man through a sliding panel into a suite of comfortably furnished rooms. Five minutes later, the cadets and the officers were enjoying their first hot meal in a week. As they ate, Major Savage brought up the purpose of their visit. "So you've come to talk to Bull c.o.xine, eh?"

"Yes," nodded Strong. "And I don't imagine he has developed any affection for me."

"No, I wouldn't say he has," replied Savage. "In fact, I don't think Bull has any affection for anyone, not even himself. Why do you want to see him, anyway?"

Strong quickly summarized the theft of the adjustable light-key and the unsuccessful search for Wallace and Simms, concluding finally with the knowledge of c.o.xine's a.s.sociation with Wallace.

"I'm hoping c.o.xine will give me a lead to Wallace's whereabouts," said Strong.

"Well, you can ask him," shrugged the major. "But personally, I don't think you're going to get any further than saying h.e.l.lo. If he'll even let you say that. He hates you, Strong. Hates you in a way I've never seen a man hate before. When you talk to him, be careful."

"I will," said Strong grimly.

"Don't let him get near you. He's the strongest man I've ever seen. Came blasted near choking a guard to death with one hand when he escaped. He could break a man's neck with both hands."

Strong smiled. "Evidently, Major, you haven't noticed the size of Cadet Astro. I'll take him along with me for protection." He looked at Astro, who flushed in quick embarra.s.sment.

"Very well, Strong," said Savage. "I'll have a jet car brought around.

You can go right down to his hut."

"Er--may I ask a question, sir?" asked Tom.

The major smiled. "Go right ahead, Corbett."

"It's about this whole setup," explained Tom. "I was expecting fences and prisoners and--well, most anything but green gra.s.s and small white buildings!"

"The little huts you saw," replied the major, "are as much of a prison as we have. Each hut holds one prisoner. He has all the necessary furniture, in addition to audioceivers and story spools which he can change once a week. He also has basic garden equipment. All prisoners grow everything they eat. Each man is dependent on himself and is restricted to the hut and the area around it. If he comes within two miles of the tower, the guards will pick him up on radar and order him back. If he comes within one mile, they fire without further warning.

Only one man has ever escaped. c.o.xine. And that was because we had a sick man on guard duty, or he never would have made it. He overpowered the guard, took his uniform, and stowed away on a supply ship. We caught him a year later."

"Didn't your radar pick up the disk he was wearing, sir?" asked Roger.

"That method of protection was only installed a few months ago," said the major.

"And the prisoners just sit there--in those little huts?" asked Astro.

"Yes, Astro!" said the major with a tone of finality in his voice. "They just sit. This is the end of the line."

The three cadets looked at each other and secretly vowed never to take a chance of doing anything that would send them to the Rock.

Five minutes later, Strong was driving a jet car along a narrow paved road toward one of the white huts. Astro sat beside him grimly silent, his hands balled into tight hamlike fists. They rounded a curve and Strong pulled up in front of the house. As they climbed out of the car, they could see the trim neat lanes of the little garden with carefully printed signs on each row indicating what was growing. They started for the house and then stopped short. Bull c.o.xine stood in the doorway, watching them.

Dressed in the snow-white coverall of the prison garb, c.o.xine faced them squarely, his thick trunklike legs spread wide apart. He was a giant of a man with long heavily muscled arms that dangled from a huge pair of shoulders. His jet-black hair was a tangled unkempt ma.s.s, and his face was scarred and lined. Eyes blazing with unconcealed hatred he waited for Captain Strong to make the first move.

"h.e.l.lo, Bull," said Strong quietly. "I'd like to talk to you."

"Oh, you would, huh?" c.o.xine spat and his lips twisted in a mocking grin. "What's the matter? Afraid to talk to me alone?" he indicated Astro. "Did you have to bring one of your s.p.a.ce Cadets for protection?"

"Listen, Bull," urged Strong, "I was your friend once. I turned you in because you were a mutineer and I was an officer of the Solar Guard. I'd do the same to this cadet if he tried what you did."

"Yeah, I'll bet you would," snarled the criminal. "Just like a real friend!" His voice deepened into a low roar. "Don't talk to me about the old days! I'm on the Rock and you're just another Solar Guard s.p.a.ce crawler to me. Now get out of here and leave me alone."

"I came to ask you to help me, Bull," Strong persisted. "I need information."

c.o.xine's eyes narrowed into slits. "What kind of information?"

"You once tried to hold up a Credit Exchange on Ganymede with a man called Gus Wallace. He had a hide-out in the asteroid belt. I'd like to know where it is," said Strong.

"Why?"

"I can't answer that, Bull."

"What do I get if I tell you?"

"Nothing, except my thanks and the thanks of the Solar Guard."

"And if I don't?"