Strong laughed. "They won't let you, Roger. They'll send up a crew of guards to search the ship. And the way these boys search makes a customs inspection look like a casual glance."

"Attention Dog Star!" A younger voice suddenly came in on the audioceiver. "This is Lieutenant Williams aboard the space launch. We are approaching your starboard catapult deck. Please open the air lock and take us aboard."

"They sure don't waste any time," commented Tom as he turned to the audioceiver. "Freighter Dog Star, Cadet Tom Corbett to Lieutenant Williams," he called, "the air lock is open and the catapult deck is ready to receive you." At the same time, the young cadet turned the valve that would open the outer air lock to the jet-boat deck.

Five minutes later, the ship was swarming with tight-lipped enlisted Solar Guardsmen, who spoke to Strong and the cadets with cool courtesy. These were men who signed up for two years as guards on the Rock after competing with thousands of other enlisted men. A guard on the Rock was paid triple wages for the two-year isolation. But more than anything else the right to wear the bright white patch with a paralo-ray gun in the center denoting their service as guards on the Rock was prestige envied even by commissioned officers of the Solar Guard.

After what Tom thought to be the most thorough search he had ever seen was over, Lieutenant Williams reported to the control deck where Strong and the cadets had been politely but firmly detained. He informed them that they were now ready to blast off to the Rock, adding that a more detailed search of the area between the ship's outer and inner hulls would be conducted after they had gone.

"You mean," said Tom, amazed, "that you actually search the four inches between the two hulls? What in the universe could we possibly hide in there?"

"I don't know, Corbett," replied Williams. "We've never found anything there." He turned to Strong and smiled. "But there's always a first time, isn't there, sir?"

"Yes, of course," agreed Strong. "You do a thorough job, Williams. Very good indeed!"

"Thank you, sir," said Williams. "You know, we've heard about you and the Polaris unit here on the Rock." He turned to Tom, Roger, and Astro. "We have a stereo of that mercuryball game you played at the Academy when you were Earthworms."

"What?" cried Tom. "You mean that game was recorded?"