As far as he could see, there was grass, spotted with small one-story buildings. To the left was a single towering structure built of Titan 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 passed 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 passed 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."
