"I know, I know," said Logan resignedly. "We're having to pay for the things we get by signing over a percentage of our future profit over the next seven years."

The three cadets looked at each other in disbelief. The idea of two men openly violating the laws of the expedition, treating the Solar Alliance citizens as if they were prisoners, was overwhelming.

Tom got up and began to pace the deck. Finally he turned and faced Logan. "Have you said anything to Vidac about this?" he asked.

"Ummmpf!" snorted Logan. "Every one of us signed a pet.i.tion and had it sent to the governor himself. We didn't even get a reply. Vidac must have heard about it and told Winters and Bush to take it easy, because the next day we were allowed to eat again without having to sign over part of our profit to them. But everything else is the same."

"But how could they force you to pay?" asked Roger. "Couldn't you refuse?"

"Sonny," declared Logan emphatically, "I'm brave as the next man. But you don't argue against a paralo-ray gun, especially when there are women and children to worry about."

Tom whirled around and faced Roger and Astro. "I guess we don't need any more proof now," he said coldly. "Jeff Marshall is thrown into the brig for looking into a logbook; we're relieved of our jobs here on the _Polaris_; my monthly report to Captain Strong isn't sent to s.p.a.ce Academy, and now this. One of two things is happening. Either Governor Hardy is in on this with Vidac, or Vidac is taking over without Hardy knowing anything about it."

"All right--all right," growled Astro, "but what are we going to do about it?"

"We've got to get word to s.p.a.ce Academy or Captain Strong someway, somehow. We've got to let them know what's going on."

"There's only one way to do that," said Roger. "But with the communications controlled by Vidac's men, we don't have the chance of a s...o...b..ll on the sunny side of Mercury!"

"Then," announced Tom firmly, "we'll have to build our own communications unit."

"But how?" asked Logan.

"Roger here can make a communicator out of spit and bailing wire," said Astro. "All he needs is the essential parts."

"Look," said Tom tensely, "Jeff Marshall will be getting out of the brig when we do. He'll be working with Professor Sykes, along with us. Why can't we build one on the sly in the observatory?"

Roger thought a moment. "It's the only thing we can do. I just hope that Mr. Logan's coming here hasn't aroused suspicion."

"Don't worry about that," said Logan. "I told Vidac I wanted this information about s.p.a.ce Academy for Billy. That seemed to satisfy him."

"I don't know," mused Tom. "He's pretty smart."

"What else can we do?" asked Astro.

"Nothing," said Tom bitterly. "Not a s.p.a.ce-blasting thing until we get out of here!"

"We've _got_ to have that triple vacuum tube," declared Roger. "That's the only thing that will transmit a voice quickly back to Earth from this fix out in s.p.a.ce."

The three boys and Jeff Marshall were back in their quarters after their first week of active duty again. They had surrept.i.tiously begun collecting parts for the communicator and were sorting them out on one of the bunks when Roger mentioned the necessity for the special vacuum tube.

"How quickly?" asked Astro.

Tom explained. "The equipment we have now is strong enough to talk to the Academy, but it'll take about six hours for my voice to reach it.

And then another six hours for the Academy's answer to get back to us.

At the end of twelve hours we might not be ready to receive and the communications officer might pick up their answer. Then we'd be in the middle of a s.p.a.ce hurricane!"

"I see," said Astro. "You've got to be able to talk directly to the Academy, so that when they answer, you'll be ready!"

"Right," said Tom. "We might only get ten or fifteen minutes of free time, when the professor would be away from the observatory."

"Where do you think I could get one of those tubes, besides on the radar bridge, Roger?" asked Jeff. He had been the main source of supply for the equipment used in the communicator. Since getting out of the brig, his movements had not been as restricted as the cadets'.

"That's just it," said Roger. "I remember distinctly loading all of them in the locker near the main scanner on the radar deck."

"Then we have to get it from another ship," said Tom. "The chances of getting one here, aboard the _Polaris_, are zero."

"Say, Roger," suddenly asked Astro, "do you think you remember enough about that triple vacuum tube to draw me a blueprint?"

"Sure," said Roger. "And you could probably build it too. But how are you going to get the inside tube vacuumized, then the second one, and finally the third. They have to be absolutely clean!"

"How about outside in s.p.a.ce?" Astro suggested. "We could take the parts of the tube with us and a.s.semble it out there. You can't ask for a better vacuum than outer s.p.a.ce."

Tom grinned and slapped the big Venusian on the back. "Astro, you're the hero of the day. Come on, Roger, start drawing that tube! Astro can make it on the power deck as if he were repairing something. Make it as simple as possible."

"Right," said Roger, "all I need is the vacuum and of course the copper filament inside the inner third tube for sending and receiving. We can make it so the tubes screw together inside of each other and then seal them."

"Right," said Astro.

"Meantime," said Tom, "Jeff and I will get you a set of earphones, if we have to tear them off the head of the radarman!"

Meanwhile, in Vidac's quarters, the second-in-command was facing the irascible Professor Sykes.

"Say that again, Professor," said Vidac. Sykes was standing before him holding a slip of paper in his hand.

"I said," the professor snorted, "that in forty-eight hours and some odd minutes we will be pa.s.sing through a very thick cl.u.s.ter of asteroids, about ten thousand miles in depth."

"Is it on our present course?" asked Vidac.

"Yes," replied Sykes. "We'll have to go around it. I wouldn't give you a plugged credit for our chances of getting through it."

"I didn't ask you for your opinion!" snapped Vidac. "All right, you've given me your information. Now get out!"

Sykes abruptly turned and left the lieutenant governor's compartment.

Alone, Vidac paced the floor. After a moment of deep thought he snapped his fingers in decision and turned on the ship's intercom.

"Corbett! Manning! Astro!" he bellowed. "Report to the control deck on the double."

A few moments later the three cadets stood before Vidac at rigid, stone-faced attention. Vidac turned on the chart projection screen and pointed to their position in s.p.a.ce.

"Professor Sykes has just warned me that the fleet is approaching a freakish asteroid cl.u.s.ter," he announced. "He estimates it to be of this size." Vidac swept his arm over the chart, taking in most of the s.p.a.ce directly in front of their path. "To go around it, over it, or under it would mean altering the course of the whole fleet and losing about six days' transit time." He turned back to the cadets who had been watching closely. "I want you three to see if you can find a route through the belt and save us the detour time." He glanced at his wrist chronograph.

"The belt is about forty-one hours ahead of us now. Take a rocket scout, look it over, and report back to me."

"Yes, sir," said Tom. "Anything else, sir?"

"Yes," said Vidac. He stepped closer to the three boys. "This is not a joy ride. I expect you to find a way through that cl.u.s.ter. You have enough time to explore the greater part of it."