"Think maybe Miles and Brett went off into one of the other side tunnels?" he asked.

Tom thought a moment. "No, I don't, Astro. We haven't hit another side tunnel since we passed that booby trap back there. What would be the use of setting that thing up if they went in another direction?"

"There must be another way out of here, then," Astro remarked.

"Why?"

"That part of the tunnel back there by the bomb was loose dirt. If the bomb had exploded, the whole tunnel would have been blocked off and how could they get out?"

Tom didn't answer. He was thinking about what he was going to do if there should be another booby trap in the tunnel. It was so dark now that they could hardly see more than a few feet ahead. The bright light was merely a pinpoint in the distance behind them.

And then Tom became aware that the roar that had been with them constantly since they had entered the shaft had now lessened in volume. But they had not passed a single branch-off tunnel where the sound could have originated. Tom made up his mind quickly.

"Come on, Astro," he said. "We're going back."

"Why?"

"I haven't time to explain now, but you walk close to one side of the shaft and I'll take the other. Feel along with your hands for anything like a door or an opening. I think we've passed them."

Without another word, Astro turned around and headed back, feeling along the tunnel wall.

It did not take the two cadets long to discover what they were looking for. A heavy wooden door was set flush with the side of the tunnel. And when Tom pressed his ear to it, he could hear the roaring sound throbbing heavily inside.

"See if you can open it, Astro," said Tom. "But take it easy."

Astro felt along the side of the door until he found a wooden latch and he lifted it gently. The door swung back, as if pushed, as a powerful draft caught it from the other side. The roar was now deafening.

Tom stepped inside cautiously, followed by Astro. They found themselves on a small balcony overlooking a huge subterranean room. In the room they saw Quent Miles and Charles Brett bending over a table on which were several delicate electronic instruments. Tom and Astro recognized them immediately as testing machinery for radioactivity, much more advanced and sensitive than the ordinary Geiger counter. Around the two men was ample evidence of Astro's original assumption that they were digging into a hot vein of uranium pitchblende. To one side of the room, lead sheets lined a rough boxlike structure that Astro and Tom guessed was covering for the radioactive vein. Against the wall lay the lead-lined suits used by the miners. Further to one side, Tom saw a huge open pipe. He nudged Astro.

"Look, over there," Tom whispered. "That's where the oxygen is coming from!"

Below them, Miles suddenly walked to the pipe and pulled a large lever on its side. The roaring sound stopped immediately and the boys felt the air pressure in the room lessen slightly.

"That blasted noise is driving me crazy," explained Miles, walking back to the table, his voice echoing in the rock-walled cavern.

Brett, leaning over the table, was stabbing around futilely in one of the sets of tubes in a complicated testing device. "Wish we had that squirt Manning here," he mumbled. "He could fix these things up in no time at all."

"I could always go back to the hide-out and get him," suggested Miles.

On the balcony Tom gripped Astro's arm tightly.

"Astro! Did you hear that?" he exclaimed.

The big cadet nodded and started to rise from their place of concealment. Tom pulled him down. "Wait," he whispered sharply. "No use barging in on them yet. Maybe we can find out where Roger is first."

Astro reluctantly crouched down again, his hamlike hands balled into fists.

The two cadets watched Quent Miles and Brett work on the instruments awhile longer. Finally Miles slammed down a pair of wire cutters on the table and growled at Brett. "No use messing with this thing any longer. I don't know what makes it tick, so I can't find the trouble. We need new equipment."

"It'll take at least two weeks to get new equipment the way things are going here at Titan," replied Brett.

"Well, there's no use hanging around here if we can't dig any more of the stuff out, and I ain't going behind that lead shield unless I got a machine that tells me it's safe."

"I've been thinking about Manning," said Brett.

"What about him?"

"Suppose we move the stuff we've already mined to the hide-out, and take this equipment along too. He can repair it out there. We can turn off the oxygen that we're sucking off from the Solar Guard pumps, and by the time we get back here, the old satellite will be back to normal. Then, with the equipment repaired and Olympia back to normal, we can really begin operations."

Quent nodded quickly. "Good idea. Come on. Let's get this stuff aboard the ship."

On the balcony Tom and Astro looked at each other.

"They're responsible for what's happened here on Titan!" whispered Tom. "They have been sucking off oxygen from the main pumps supporting the force field."

"Come on, Tom," growled Astro. "My fist is just itching to make contact with a couple of no-good chins."

"Not so fast! We still don't know where they've got Roger."

"You want to keep on following them?" asked Astro.

"At least to their ship," Tom replied. "Then we can notify Captain Strong and he can track them in the Polaris. If we barge in on them now, we'll just get the satisfaction of knocking their heads together with no guarantee of any information." The young cadet turned to the door. "We'll sneak up the tunnel a way and then follow them out."

"Hurry!" said Astro. "Here they come." Quent, carrying one of the instruments, had started up the steps to the balcony.

Tom grabbed the latch and pushed up but the door would not open. "Give me a hand, Astro, quick!" he called.

Astro grabbed the latch and heaved his bulk against the door. Suddenly he stepped back dumfounded, holding the latch in his hand. It had snapped off.

Just at that moment Brett looked up and saw them. He shouted a warning to Miles, who dropped the instrument he was carrying and pulled out his ray gun.

"Just stand where you are!" he snarled, leveling the gun at them.

Tom and Astro stood quietly, hands in the air.

"How in blazes did they get here?" Brett cried.

"They must have followed me," said Miles. "They certainly couldn't have known about this place."

"But how did they get past the trap?" Brett persisted, still amazed and shaken by the unexpected appearance of the cadets.

Astro snorted his contempt. "You must think we're a couple of prize space jerks," he growled. "You can't even kill a mouse with that thing now."

"Let's cut the talk," said Miles. "What do we do with them?"

"Freeze them!" snapped Brett. "No telling how long they've been here and how much they know."

"We know enough to put you on a prison asteroid," challenged Tom.

"Freeze 'em, it is," said Quent. "We'll get the ship loaded and decide what to do with them later."

He pressed the trigger on his ray gun. There was a harsh crackling sound and Tom and Astro stiffened into immobility, every nerve and muscle deadened. With the exception of their hearts, and sense of seeing and hearing, they might have been dead men.

Laughing to themselves, Quent Miles and Charles Brett picked up their instruments, walked past them, and disappeared through the door.



CHAPTER 14

Charles Brett swaggered into the control room of the electronics building. Commander Walters, Captain Strong, and Kit Barnard looked up from their study of the reports the chief engineer had handed them.

"What are you doing here, Brett?" demanded Walters. "I thought you had blasted out of here long ago."

"I'm leaving as soon as we sign the contracts for hauling the crystal, Commander," said Brett.

"Contracts!" exploded Strong. "Why, man, do you realize that this satellite is about to die? If we don't find out what's wrong with the screens, there won't be any crystal mined here for the next ten years."

Brett shook his head and smiled. "That's all right with me too," he said. "The contracts call for either party to satisfy the other should either party fail to fulfill the contractual agreements. In other words, Strong, I get paid for making the trip out to Titan, whether you have crystal to haul or not."

"Why, you dirty—" snarled Strong.

"Just a moment, Steve," Walters interrupted sharply. "Brett's right. We had no way of knowing that this situation would arise, or grow worse than it was in the beginning. Brett went to a great deal of expense to enter the race and win it. If he insists that the Solar Guard abide by the contract, there's nothing we can do but pay."

"It won't be too bad, Commander Walters," said Brett. "I have my ship loaded with crystal now, and if you'll just sign the contracts, I can deliver one cargo of crystal to Atom City before Titan is abandoned."

"Wait a minute," cried Strong. "Who gave you the right to load crystal before signing the contract?"

"I assumed the right, Captain Strong," replied Brett smoothly. "My ship won the race, didn't it? Why shouldn't I start work right away?"

"Well, that's beside the point now, anyway," Walters said. "We may need your ship to take miners and their families to Ganymede or Mars, Brett. Never mind the crystal. One load won't mean very much, anyway."

"No, thank you," growled Brett. "I don't haul any miners in my ship. The contracts call for crystal and that's all."

"I'm ordering you to take those people, Brett," said Walters coldly. "This is an emergency."

"Order all you want," snapped Brett. "Look at your space code book, section four, paragraph six. My rights are fully protected from high-handed orders issued by men like you who think they're bigger than the rest of the people."

Walters flushed angrily. "Get out!" he roared.

"Not till you sign that contract," Brett persisted. "And if I don't leave with a signed contract in my pocket, I'll have you up before the Solar Alliance Council on charges of fraud. You haven't got a leg to stand on and you know it. Now sign that contract."

Abruptly, Walters turned to an enlisted spaceman and instructed him to get his brief case from the Polaris, then deliberately turning his back on Brett, continued his study of the report. Strong and Kit Barnard watched Brett with narrowed eyes as the arrogant company owner crossed to the other side of the room and sat down.

"You know something, Steve," said Kit quietly. "Back at the Academy, I failed to register a protest about someone dumping impure reactant into my feeders."

"What about it?" asked Strong.

"I'd like to register that protest now."

"Now?" Steve looked at him, a frown on his face. "Why now?"

"For one thing, Brett couldn't blast off until there was an investigation."

"You might have something there, Kit," replied Strong with a smile. "And since Brett won the race under such—er—mysterious circumstances, I'd suggest an investigation of the black ship as well, eh?"

Kit grinned. "Shall I make that a formal request?"

"Right now, if you like."

Kit turned to face Commander Walters. "Commander," he announced, "I would like to register a formal protest with regard to the race."

Walters glanced up. "Race?" he growled. "What the devil are you talking about, Kit?"

"Captain Barnard seems to think that Mr. Brett's ship might have used equipment that was not standard, sir," Strong explained. "In addition, his own ship was sabotaged during the time trials."

Walters looked at Strong and then at Kit Barnard, unable to understand. "What's happened to you two? Bringing up a thing like that at this time. Have you lost your senses?"

"No, sir," replied Kit. "But I believe that if a formal investigation was started, the Solar Guard would be within its legal rights to delay signing the contracts until such investigation was completed."

Walters grinned broadly. "Of course! Of course!"

Brett jumped up and stormed across the room. "You can't get away with this, Walters!" he shouted. "I won this race fairly and squarely. You have to sign that contract."

"Mr. Brett," said Walters coldly, "under the circumstances, I don't have to do a space-blasted thing." He turned to Kit. "Is this a formal request for an investigation, Kit?" He was smiling.

"It is, sir."

"Very well," said Walters, turning to Brett. "Mr. Brett, in the presence of two witnesses, I refuse to sign the contracts as a result of serious charges brought against you by one of the participating entrants. You will be notified of the time and place of the hearing on these charges."

Brett's face turned livid. "You can't do this to me!"

Walters turned to one of the enlisted guardsmen. "Escort Mr. Brett from the room," he ordered.

A tall, husky spaceman unlimbered his paralo-ray rifle and nudged Brett from the room. "I'll get even with you, Walters, if it's the last thing I do," he screamed.

"You make another threat like that to a Solar Guard officer," growled the enlisted spaceman, "and it'll be the last thing you do."

As the door closed, Walters, Strong, and Kit laughed out loud. A few seconds later, as the three men returned to their study of the report, there was a distant rumble, followed quickly by the shock wave of a tremendous explosion. Walters, Strong, and Kit and everyone in the room were thrown to the floor violently.

"By the craters of Luna," yelled Strong, "what was that?"

"One of the smaller screens has given way, sir!" yelled the chief electronic engineer after a quick glance at the giant control board. "Number seven."

Walters struggled to his feet. "Where is it?" he demanded.

Strong and Kit got to their feet and crowded around the commander as the engineer pointed out the section on the huge map hanging on the wall.

"Here it is, sir," he said. "Sector twelve."

"Has that area been evacuated yet?" asked Strong.

"I don't know, sir," replied the engineer. "Captain Howard was in charge of all evacuation operations."

Walters spun around. "Get Howard, Steve. Find out if that part of the city has been cleared," he ordered and then turned to Kit. "You, Kit, take the Space Marines and round up every spare oxygen mask you can find and get it over to that section right away. I'll meet you here"—he placed his finger on the map—"with every jet car I can find. No telling how many people are still there and we have to get them out."

Almost immediately the wailing of emergency sirens could be heard spreading the alarm over the city. At the spaceport, where the citizens were waiting to be taken off the satellite, small groups began to charge toward the loading ships in a frenzy of fear. Since Titan had been colonized, there had never been a single occasion where the sirens had warned of the failure of the screens. There had been many tests, especially for the school-age children and the miners working far below the surface of the satellite, but this was the first time the sirens howled a real warning of danger and death.

Strong raced back to the control tower of the spaceport in a jet car and burst into the room where the captain was still asleep on the couch. Strong shook him violently.

"Wake up, Joe!" he cried. "Come on. Wake up."

"Uh—ahhh? What's the—?" Howard sat up and blinked his eyes. "Steve, what's going on?"

"The screen at sector twelve has collapsed. How many people are still in there?"

"Collapsed! Sector twelve?" Howard, still groggy with sleep, dumbly repeated what Strong had said.

Strong drew back his hand and slapped him across the face. "Come out of it, Joe!" he barked.

Howard reeled back and then sat up, fully awake.

"What—what did you say?" he stammered.

"Sector twelve has gone," Strong repeated. "How many people are left there?"

"We haven't even begun operations there yet," Howard replied grimly. "How long have I been asleep?"

"A couple of hours."

"Then there's still time."

"What do you mean?"

"Just before I folded, I ordered the evacuation crews to start working on sector eleven. They should be finished now and just about starting on twelve. If they have, we have a good chance of saving everyone."

"Let's go."

The two men raced out of the control tower to the jet car and roared through the desolate streets of the city. All around them commandeered jet cars raced toward the critical area. Commander Walters stood in the middle of an intersection on the main road to sector twelve, waving his arms and shouting orders to the enlisted guardsmen and volunteer miners that had raced back into the city to help. On the sidewalk, enlisted guardsmen handed out extra oxygen masks to the men who would search the area for anyone who might not have gotten out before the screen exploded. The main evacuation force that had been under Howard's supervision had already moved in but there was still a large area to cover.

"We'll split up into six sections!" roared Walters, standing on top of a jet car. "Go down every street and alley, and make a house-to-house search. Cover every square inch of the sector. If we lose one life, we will have failed. Move out!"

With Strong, Kit, Howard, Walters, and other officers of the Solar Guard in the lead, the grim lines of men separated into smaller groups and started their march through the deserted city. The swirling gas already was down to within a hundred feet of the street level. When it dropped to the surface, each man knew there would be little hope for anyone remaining alive without oxygen masks.

Every room of every house and building was searched, as over all, the deadly swirling gas dropped lower and lower and the pressure of the oxygen was dissipated.

Once, Strong broke open the door to a cheap rooming house and raced through it searching each room. He found no one, but something made him go back through the first-floor rooms again. Under a bed in a room at the end of the hall he found a young boy huddled with his dog, wide-eyed with fear. Such incidents were repeated over and over as the searchers came upon sleeping miners, sick mothers and children, elderly couples that were unable to move. Each time they were taken outside to a jet car where masks were strapped over their faces, and then driven to the spaceport. And, all the while, the deadly methane ammonia gas dropped lower and lower until it was within ten feet of the ground.

There were only a few buildings left to search now. The lines of the men had reached the open grassy areas surrounding the city proper, and as they collected in groups and exchanged information, Walters gathered them together.

"You've done a fine job, all of you," he said. "I don't think there's a living thing left in this entire sector. All volunteers and the first four squads of enlisted guardsmen and second detachment of Space Marines return to the spaceport and prepare to abandon Titan. Give all the aid to the officer in charge that you can. Again, I want to thank you for your help."

As the group of men broke up and began drifting away, Walters hurried over to Strong and Kit Barnard. "Steve," he said, "I want you to supervise the evacuation at the spaceport. Since this screen has blown up, those poor people are frightened out of their wits. And they have a right to be. If a major screen blew instead of a small one, we really would be in trouble."

"Very well, sir," replied Strong. "Come on, Kit, you might as well blast off with a load of children."

"Sure thing."

"Just a minute," Walters interrupted. "I would consider it a service, Kit, if you would send your young assistant back with your ship and you stick around until we get all the people safely off."

"Anything I can do to help, sir," replied Kit.

At that moment a tall enlisted spaceman walked up to Walters and saluted sharply. Walters noticed the stripes on his sleeve and his young-looking face. He couldn't remember ever seeing such a young master sergeant.

"Captain Howard asked me to make my report to you, sir," said the guardsman.

"Very well, sergeant," said Walters.

The young spaceman made a detailed report of his search through sectors eleven and twelve. While he spoke, Strong kept looking at him, puzzled. When the guardsman had finished, Strong asked, "Don't I know you from somewhere, Sergeant?"

The guardsman smiled. "You sure do, Captain Strong. My name's Morgan, sir. I was a cadet with Tom Corbett and Astro, sir, but I washed out. So I joined the enlisted guard."

"Congratulations, Sergeant," said Walters. "You're the youngest top kick I've ever seen." He turned to Strong. "Apparently we slipped up, Steve, letting this chap get out of the Academy so he could make a name for himself in the enlisted ranks."

"Thank you, sir," replied Morgan, blushing with pride.

"Have you seen the cadets, by any chance, Sergeant?" asked Strong. "They're both here on Titan with me."

"Oh, yes, sir," said Morgan. "I saw them some time ago."

"Where?"

"A few blocks closer to the heart of town," said Morgan, pointing back down the avenue. "We were just starting in on sector eleven and I saw them coming out of a restaurant."

"Funny they haven't returned," commented Walters. "And what would they be doing down there?"

Strong's forehead creased into a frown of worry. "Sir, I wonder if you'd allow me a half hour or so to look for them?" he asked. "If they were anywhere near this section when the screen collapsed, they could have been injured by the sudden release of pressure."

"They had masks, sir," said Morgan. "I gave them a couple myself."

Walters thought a moment. "It's just possible they might have been injured in some way," he mused. "Go ahead, Steve. If you don't find them, and they don't show up at the spaceport, we'll organize a full search."

"Thank you, sir," said Strong. "You come along with me, Sergeant."

Adjusting their oxygen masks, Captain Strong and Sergeant Morgan strode down the street through the swirling mist of deadly methane ammonia to begin their search for Tom and Astro.



CHAPTER 15

"Listen!"

Captain Strong grabbed the young master sergeant by the arm and stood stock-still in the swirling methane ammonia gas, his eyes searching the misty sky.

"What is it, sir?" asked Morgan.

"A spaceship decelerating," said Strong, "coming in for a touchdown!"

"I think I hear it now, sir!" said Morgan.

"Can you figure out where it is? I can't see a blasted thing."

"Sounds to me as though it's to the left, sir."

"O.K., let's go and investigate," said Strong. "There isn't any good reason for a ship coming down in this deadly soup—or in this area."

Walking slowly and cautiously, the two spacemen angled to the left, peering through the clouds of gas that seemed to get thicker as they moved along. The roaring blast of the ship became louder.

Strong put his hand out to stop Morgan. "Let's hold up a minute, Sergeant," he said. "I don't want to get too close until I know what we're facing."

They stood absolutely still, the gas swirling around them in undulating clouds that grew thicker one minute and then thinned out again. As the gas thinned for a few seconds, Strong gasped and pointed.

"Look!" he cried. "By the craters of Luna, it's Brett's ship!"

"Brett?" asked Morgan.

"Charles Brett. He owns that ship. It's the one that won the space race from Earth. Now, what would he be doing landing out here?"

"I think he came down beside that warehouse up ahead, sir," said Morgan, as the gas cloud closed in again, cutting off their view of the actual landing. "It used to be a storehouse for mining gear a couple of years ago, but it's been empty for some time."

"I think we'd better check this, Sergeant," said Strong firmly. "Come on."

Strong started forward, then stopped, as a particularly heavy cloud of the deadly gas swirled around them. The two spacemen clung together blinded by the dense methane ammonia that would kill them in thirty seconds should their oxygen masks fail. In a moment the foggy death thinned out again and they continued toward the warehouse and the sleek black ship behind it.

* * * * *

Tom Corbett and Astro heard the roaring blast of the ship's exhaust. They saw Brett and Miles haul the instruments out of the cavern. They saw; they could hear; but they could not move. For nearly three hours they had remained alone in the cavern, frozen in the exact position they were in when Quent Miles had blasted them with his paralo-ray gun. And then Brett and Miles were standing before them again, Miles covering them with his paralo-ray gun.

"Why should we break our backs loading the ship?" sneered Miles. "Let them carry it out for us."



"All right, release them," agreed Brett. "But get that stuff loaded in a hurry. Walters is either getting suspicious or he's pulling a bluff. We can't take any more chances."

Miles flipped on the neutralizer switch of the paralo ray and leveled it at Tom. "We'll take the little fella first," he said. "If he acts up, we'll just leave the other fella the way he is."

He fired at Tom, and the young cadet began to shudder violently. His teeth chattered and he found it difficult to focus his eyes as his nervous system tried to shake off the effects of the ray. He crumpled to a heap on the balcony floor and gasped for breath.

"He won't be much use to you for a while." Brett laughed. "Look at him flopping around like a fish out of water."

"Get up!" snarled Miles at Tom, quickly flipping the ray gun back to positive charge. "Come on. You're not that bad off. Get up." He leaned over and prodded the cadet with the gun. "If you don't get up, I'll freeze you again," he threatened.

Tom struggled to his feet. "I'll get you for this, Miles," he gasped weakly, his teeth still chattering.

"Never mind the hot air!" snarled Brett. "Go down there and start hauling up those boxes."

Tom turned helplessly and stumbled down the stairs to the floor of the cavern.

"Now for the big fellow," said Miles. He fired the neutralizer charge and Astro started to quiver at the shock of the release. But he clamped his teeth together and made a quick lunge for Miles, reaching for the spaceman's throat. Expecting the attack, Miles stepped aside quickly and brought the gun down sharply on the big cadet's head. Astro dropped to the floor, half-stunned. The black-clad spaceman leveled the ray gun and sneered, "Try that again, you overgrown punk, and I'll drop you on your head."

Astro shook his head and stumbled to his feet. He glared at Miles, spun away, and walked down the stairs shakily.

Miles and Brett stood on the balcony and watched the two cadets working on the cavern floor. "Hurry it up there!" shouted Miles. "We haven't got all day."

Brett took his ray gun from his belt and stepped forward. "I'll handle Corbett," he said. "You take care of the big one."

"Right," replied Miles. "But stay well in back of them and keep your gun on them all the time."

"How long do you think it'll take to get the ship loaded?" asked Brett.

"Couple of hours. But what are you going to do about Walters if he's wise?" Miles shrugged his shoulders.

"Simple," said Brett. "We take the stuff we've got, haul it to the hide-out, dump it, and return to Atom City. Then we just sit tight and wait until the situation clears up here on Titan."

"What about that investigation?" asked Miles, keeping his eyes on the cadets, who were now staggering back to the stairs, each carrying a heavy lead box containing the precious uranium pitchblende.

"What can an investigation prove?" snorted Brett.

"I don't know. Walters and Strong are pretty smart cookies."

"Unless they have witnesses that you were messing around Kit Barnard's ship, which they don't, and unless they find out about Ross, which they won't, there isn't anything they can do."

Miles looked down at the shorter man beside him. "Ross, eh?" He laughed.

Brett stared at him and then shrugged. "I always get mixed up," he said. "But you know what I mean."

"Sure, I know." Miles turned to watch Astro and Tom start up the stairs to the balcony, the lead boxes on their shoulders. "What are you going to do with them?" he said.

"Take them to the hide-out and decide later. Besides, they'll be handy for unloading the ship."

"Good idea," nodded Miles. He took a deep breath and smiled. "I sure wish I could see Walters' face when he learns about the new load of uranium that'll flood the market."

Brett laughed. "Yeah, and with the customs clearance we'll get to haul in the crystal, there'll be no way they can figure out how it's getting in."

Miles turned and shouted at the two cadets struggling up the stairs. "Come on, you two. Get a move on."

"We're making it as fast as we can, Miles," Astro protested.

"It ain't fast enough," sneered the spaceman. He reached out with his free hand and slapped Astro across the mouth. "That's just to remind you to watch your tongue, or you might wind up an icicle again."

Astro dropped the box and crouched, his big frame ready to be released like a coiled spring. Miles backed up and fingered the trigger on the ray gun. "Come on, stupid," he snarled. "Come on, I'll give it to you again, only this time—" He smiled.

"No, Astro," called Tom. "There's nothing we can do now. No use getting frozen again."

"That's using your head, Corbett." Miles laughed. "Pick up that box and get going."

Astro picked up the lead box again and staggered after Tom toward the door. Miles and Brett stepped back, guns ready, and watched the two cadets walk slowly ahead of them into the tunnel.

* * * * *

Captain Strong and Sergeant Morgan crept to the side of the warehouse and flattened themselves against the wall. With the gas swirling around them thicker than ever, they found it more difficult than ever to see where they were going.

"I think I see a door ahead," said Strong.

"Want me to see if it'll open, sir?" asked Morgan.

"No. I'll look around in the warehouse," replied the Solar Guard captain. "You investigate the ship. If anyone's aboard, keep him there until I contact you. If not, come back here and wait for me."

"Very well, sir," said Morgan, and turned toward the black ship. In a moment he was lost in the deadly mist.

Strong made his way to the door and twisted the latch. The door slid open easily, and he stepped inside, closing it behind him and waiting for some signs of life or movement. The gas was like a thick fog in the room and he inched his way forward, hands outstretched like a blind person. Gradually he began to see the vague form of a door on the opposite wall and he made his way toward it, completely unaware that he came within inches of falling through the open trap door in the floor.

He opened the door in the wall slowly, peering inside cautiously. He was startled to feel the faint rush of air on his hands and to see the room clear of the dangerous methane ammonia gas. He moved quickly inside and made a hurried inspection of the gear, not bothering to look to examine it closely. He shrugged his shoulders. It was just as Morgan had said. An abandoned warehouse with old mining gear and nothing else.

Suddenly he stopped. There was something strange about the room and he looked around again. The gas! There were no ammonia vapors in the room. He quickly searched along the walls for some outlet of oxygen, remembering now the rush of air he had felt as he opened the door. Close to a corner near the door, he found a small opening. Air poured out of it in a steady rush. He straightened up, his face grim. "So that's it," he said to himself. "Somebody has been sucking off oxygen from the main pumps!"

Strong headed for the door. "But why?" he asked himself. "Why in this particular building?"

He strode out of the room and inched his way across the outer room toward the front door, again narrowly missing the open trap door.

Once outside, he made his way along the side of the building in the direction that Morgan had taken. When he reached the corner, he could see the black bulk of the Space Knight a hundred yards away. He ran toward the base of the ship and met Morgan coming toward him.

"Find anything, Sergeant?" he called.

"Nothing, sir," replied Morgan. "The ship is ready to blast off and her cargo holds are full. But that's all."

"Full of what?"

"I couldn't see, sir. The main hatch was locked and I could only see through the viewport. But it just looked like general cargo to me."

"Couldn't have been crystal?"

"It might have been, sir. It was pretty dark in the hold but it looked like a lot of boxes to me."

"You don't put crystal blocks in boxes," said Strong.

"Sometimes they do, sir. The more expensive grades are crated, so that the surfaces won't get scratched. Pieces that are going to be used for outer facings on a building, for instance."

"All right, Sergeant. But I found something back in that building that is going to prove very interesting."

"The cadets, sir?"

"No. An illegal use of oxygen!"

Quickly Strong explained his discovery, concluding, "Come on. We're going back in there for a closer inspection!"

"But we can't, sir," said Morgan.

"Why not?"

"We only have enough oxygen left in our tanks to get us back to the cleared area."

"Blast it!" growled Strong. "Aren't there any masks aboard the ship?"

"No, sir," replied Morgan.

"Very well, then. The only thing we can do is go back and bring out a searching party in force." Strong turned and walked rapidly away. "Come on, Sergeant, I think we're on the way to answering a lot of questions about the failure of the screens."

Almost running, the two spacemen disappeared into the swirling mist of deadly gases.

No sooner were they out of sight than Tom Corbett and Astro, faces covered with oxygen masks, emerged from the warehouse and headed toward the ship, Miles and Brett close behind them with paralo-ray guns leveled at their backs.



CHAPTER 16

Roger Manning opened his eyes, then closed them. He lay perfectly still and listened. The sound he heard was the unmistakable blasting roar of a spaceship. But there was another sound, much closer. In fact, it was in the room with him.

He opened one eye to see Quent Miles moving about in the one-room, airtight space hut which had been his jail for the last week. Miles was throwing clothes into a space bag, keeping a wary eye on Roger, sprawled on the bunk. Hoisting the bag to his shoulder, Miles closed the face plate of his space helmet, turned to the air lock, and stepped inside, slamming the portal behind him. From the bunk, Roger could hear the hissing of the change of pressure inside the lock from normal to the vacuum of space outside.

The entire week had been a time of waiting and wondering. He couldn't understand Miles' actions in taking him prisoner the moment before blast-off from Earth, and then keeping him at the asteroid, seemingly giving up all chances of winning the race.

Roger waited until he was sure that the black-clad spaceman had gone, then he sat up and worked desperately on the thin metal chain binding his wrists. He had been working on one of the links ever since his arrival at Miles' strange asteroid base, scraping it against the rough metal edge of one of the legs of his bunk. Two days before, he had succeeded in wearing it down to a point where he could snap it easily when the opportunity came for him to make a break. But so far the chance had not presented itself. He had been kept prisoner in the space hut, and Miles had pushed his food in through a vent in the air lock. Now, however, with the sound of the spaceship outside, the cadet decided it was time for action.

Working quickly, Roger snapped the link and tore off the chain, freeing his hands. He allowed himself the longed-for luxury of stretching just once, and then crossed to the small locker beside the air-lock door to take out a space suit. He climbed into it hurriedly, secured the helmet, and began searching the small room for a weapon. In the bottom of a chest he found a rocketman's wrench. Grasping it tightly, he stepped into the air lock. Just before he turned on the oxygen in his space suit, he listened again for the noise of the blasting ship. Then he grinned as he realized that it wasn't the noise of the ship he heard, but the vibration it created on the surface of the asteroid. Sound wouldn't travel through the vacuum of space outside. Suddenly it stopped and Roger realized the tubes were being blasted in preparation for take-off. The young cadet closed the inner portal of the lock, adjusted the pressure, turned on the oxygen of his suit, and waited. In a moment the indicator showed the pressure to be equal to that outside in space, and he opened the outer portal cautiously.

A section of the asteroid belt swam above him. Hundreds of small planetoids and various-sized pieces of space junk drifted in the cold vacuum of space overhead. Roger looked around. The asteroid he was on was so small and the horizon such a short distance away that the base of Miles' giant black ship was half-covered by the curvature of the planetoid.

Holding the wrench tightly in his hand, the blond-haired cadet circled around the space hut cautiously, looking for Quent Miles, but the spaceman was nowhere in sight. He had walked all the way around the hut and back to the air lock when he saw a movement out of the corner of his eye. It was Miles, returning to the space hut. Moving quickly, Roger ducked behind a huge boulder and waited for Miles to come closer. It would be impossible to hit Miles with the heavy wrench. The space helmet would ward off the blow. His only chance was to get aboard the ship while Miles was inside the hut. And he would have to move fast. When Miles discovered the hut was empty, he would come looking for the young cadet.

But to the cadet's great relief, Miles went past the hut and disappeared over the horizon of the asteroid in the opposite direction.

Slipping out from behind the boulder and utilizing the near lack of gravity, Roger ran in giant leaps toward the black spaceship. His last jump brought him to the base of the ship where he quickly clambered up the ladder, opened the portal, and slipped into the air lock. In a matter of seconds he had built up the pressure in the lock to equal the pressure inside the ship. He opened the inner portal and raced up the ladder to the control deck. Throwing himself into the pilot's chair, he prepared to raise ship. Then he slumped in despair. The master switch had been removed. It was impossible for him to blast off!

He leaped out of the chair and scrambled up the ladder to the radar deck. He flipped on the audioceiver and nervously waited for the tubes to warm up. Nothing happened. Only then he remembered that the communications would not work without power from the generators and they could not be started without the master switch.

"Boy! He sure wasn't taking any chances of me getting away and leaving him here," Roger muttered to himself, as he turned back to the ladder and climbed down to the air lock. He stepped inside, and crossing to the small viewport, looked out over the dead landscape of the tiny world for a sign of Quent Miles. He saw the black-clad spaceman returning toward the hut. Roger held his breath. If Miles went into the hut this time and found him missing, he would know that the cadet was aboard the ship. "Manning," Roger said to himself, "if you ever needed luck, you need it now!"

Miles walked slowly, as if in no hurry, still heading for the space hut. But as Roger held his breath in fear, he passed it again, without so much as pausing to look at it.

Roger grinned. "Spaceman, you are going to say your prayers every night after this," he murmured.

The cadet turned, and racing as fast as the cumbersome space suit would allow him, headed toward the power deck. Passing the galley, he snatched up several plastic packages of food.

Down on the power deck, Roger went directly to the lead baffling shields around the reactant chambers and carefully squeezed between them and the outer hull. It was going to be a rough ride on the power deck, jammed in behind the firing chambers, but at least he was hidden—and more important, free.

He listened for the clank of metal shoes on the ladder above him. When he heard them, followed closely by the slam of the air-lock portal, he grinned in satisfaction. Opening one of the plastic bags, he began to eat.

In a moment the ship came to life and the power deck became a raging torrent of noise and vibration. As Roger braced himself, he felt the ship quiver and then shake, as under heavy acceleration, it blasted off into space.

* * * * *

Captain Strong and young Sergeant Morgan hailed a passing jet truck loaded with Space Marines. "Get me to Commander Walters right away, Lieutenant!" said Strong to the young officer in charge. "This is an emergency."

"Yes, sir," acknowledged the young officer, and sent the truck roaring down the empty avenue toward the electronics building where Walters was still checking the reports on the screens.

"Is there anything new, sir?" asked the young officer. "Have the technicians been able to find out what's making the screens fail?"

"We're on the right track, Lieutenant," said Strong shortly. "Can't you get any more speed out of this thing?"



"Yes, sir," replied the officer. He rammed the accelerator to the floor and the small truck blasted through the streets as though shot out of cannon.

In a few minutes the truck screamed to a halt in front of the building and Strong leaped toward the door, followed closely by Sergeant Morgan and the Space Marine lieutenant.

Strong found Walters before the telemetering board waiting impatiently for some figures Dr. Joan Dale had sent him to be analyzed and evaluated. He spun around when Strong entered the room at a dead run.

"Steve!" he exclaimed. "What's the matter? Anything happen to the cadets?"

"We didn't find them, sir, but we did find something else. We—" Before Strong could finish, the calculator began pouring out its answers.

"Excuse me, Steve! These figures could tell us why the screens are failing."

"But I know why they're failing, sir!" shouted Strong.

"You know what?" exclaimed Walters.

As all the men in the room stared at him, Strong hurriedly told the commanding officer what he had found, concluding, "I think the room I stumbled into was used as a repair shop. But it was gas-free and pure oxygen was coming out of the pipe I described."

"I see," said Walters grimly. "Let me check that against these figures." He turned to the calculator and with the assistance of Joe Howard, Kit Barnard, and the chief electronics engineer began studying the figures.

Strong paced up and down nervously. The faces of the technicians in the room clearly showed the strain they had been under the past few days. And when they heard the startling news Strong had delivered, there wasn't one who didn't feel his fingers tighten into fists at Brett and Miles' selfishness.

Walters straightened up and glanced at the faces of the men around him. "Well, gentlemen," he said. "I think the figures speak for themselves."

There was a murmur of agreement. Walters turned back to Strong. "Those figures prove conclusively that what you say is true. It is impossible for the screens to collapse except from a vital leak—exactly such a leak as you have described."

Walters turned and began to snap orders to the men around him. "I want every available man sent out on the double. I want every inch of that area searched for an opening to a mine shaft or anything that leads underground. Take half the men off the spaceport detail."

"Shall we continue evacuation operations for the miners and their families?" asked the young Space Marine lieutenant. "There is quite a force of men out there that could be used in the search."

"What do you think, Steve? Should we take off the guardsmen and suspend evacuation in the hope that we can find that leak?"

"I would say yes, Commander," said Strong. "Your figures and those Dr. Dale sent you point to a leak of this nature."

"Very well, Lieutenant," said Walters. "Order every man to the area and begin search operations immediately. I want that leak found—and found fast! And I want Charles Brett and Quent Miles arrested at once!"

* * * * *

Tom and Astro bent over the lead boxes again and heaved them to their shoulders. A quick glance showed them that Miles had not followed them to the floor of the cavern as he had done before, but had remained on guard on the balcony.

As they struggled to lift the boxes to their shoulders, Tom whispered out of the side of his mouth, "I know how we can get out of here, Astro."

"How?"

"Since Brett is staying on the ship for this trip, Miles is going to have trouble watching both of us."

"Yeah, I know," muttered Astro. "Want me to jump him?"

"No," Tom growled. "Miles has been trailing us through the tunnel by twenty to thirty feet each trip. When we pass that spot where the light is, you drop your box. He'll be watching you then and that will give me a chance to grab that booby trap you took apart, remember?"

"Yeah!"

"O.K. Now remember, when I give you the word, you drop your box on the right-hand side of the tunnel."

"Hurry up down there!" yelled Miles from the balcony. "We haven't got all night."

"Keep your shirt on, buster," growled Astro. "We're tired."

The two cadets balanced the heavy lead boxes on their shoulders, and, with Tom leading the way, climbed up the stairs past Miles and started up the tunnel in front of the black-suited spaceman.

They walked slowly, side by side, and as before, Miles stayed a good twenty paces behind them. As they neared the light where they knew the explosive charge would be, Tom began slowing his pace.

"Come on, get going, Corbett!" Miles yelled.

"He's tired," said Astro. "Leave him alone."

"What are you, his protector?" snarled Miles. "Get going, I said."

"O.K.," said Tom, struggling forward.

They came closer and closer to the light. Tom glanced at Astro and winked. Astro winked back and braced himself to fake the accident.

As closely as Tom could remember, Astro had tossed the charge to one side about ten feet beyond the light. If he knew exactly where it was, he could fall forward on top of it and stuff it in his tunic. He tried to recreate the scene as it happened. They passed under the light. One step ... two steps ... three steps.... "Now, Astro," Tom whispered.

The big cadet lunged to one side, dropping the heavy box to the floor. At the same time, Tom dropped his box and lunged forward, arms outstretched, feeling along the floor for the precious explosives.

Miles ran up quickly, ray gun cocked and ready.

"Get up!" he shouted. "Get up or I'll freeze you both and leave you here!"

Tom and Astro struggled to their feet. They lifted the heavy boxes to their shoulders and started down the tunnel again.

When Astro dared a glance at Tom, he saw his unit mate grin and wink at him. Astro winked back. Suddenly it seemed that the heavy lead box was as light as air!



CHAPTER 17

The streets of Olympia echoed to the thunderous roar of jet trucks and jet cars racing to sector twelve. Miners, Solar Guardsmen, and Space Marines jammed the vehicles, their faces grim with determination as they prepared for an all-out attempt to prevent the death of the colony.

Walters, Strong, and Kit Barnard sat behind Blake, the Space Marine lieutenant, and Sergeant Morgan as they rocketed through the streets. There was little conversation, each man thinking bitterly of Charles Brett and Quent Miles. Walters had already foreseen the possibility of trouble with emotional miners and had ordered Blake to be personally responsible for the safety of Miles and Brett when they were arrested.

"They get a fair trial like anyone else," declared Walters. "And they are innocent until proven guilty by a jury."

Now, as he sat beside Strong, Walters wondered if they would be able to save the city from the ammonia gas. He had taken a calculated risk in ordering guardsmen at the spaceport to aid in this search. If they should fail to find the leak, and the gas death spread farther across the city, the miners and their families would be helpless before it. The thought of the riots that would ensue if the people tried to get aboard the spaceships without order made the hardened commander shudder.

The jet car slowed and finally stopped. "What's the matter?" growled Walters.

"This is as far as we can go in the car, sir," replied Blake. "The gas is so thick I can't see where I'm driving."

"Very well. Put on your masks," Walters announced. "Keep in contact with the spaceport control tower. They'll relay messages to me and my orders back to you. Let's go. Spaceman's luck."

The men opened the doors of the small jet car and stepped out into the swirling mists. Though there were more than a thousand men searching the area, they could not rid themselves of a strange feeling of loneliness as they each walked forward into the mists of death.

Strong and Walters inched their way down the street like blind men, feeling for each step with hesitant feet.

"Are you sure we're heading in the right direction, Steve?" asked Walters.

"Yes, Commander," replied Strong. "The warehouse is located about a half mile down this street."

"Of all the blasted messes," grumbled Walters. "We've got the finest radar system in the universe and we have to walk along here feeling our way like blind men."

"There's no other way, I'm afraid," said Strong grimly.

"Are you still with us, Kit?" called Walters.

"Right here, sir," came Barnard's voice, immediately behind them.

The spacemen continued their slow march through the mist in silence. Once, when Walters stumbled and nearly fell, he roared angrily.

"By the craters of Luna, when I get my hands on those two space crawlers, there won't be enough of them left for a trial!"

"Yes, sir," said Steve. "But if anything has happened to those cadets, you'll have to excuse ranks, sir, and wait your turn."

"Of course!" Walters exclaimed a moment later. "That's what happened to Manning! He didn't run away. He must have gotten on to them during the trip out here and they shut him up."

"Exactly what I was thinking, sir," said Strong, and then suddenly stopped. "I just bumped into a wall. We're here."

* * * * *

Tom and Astro climbed wearily through the trap door into the room above the main shaft while Quent Miles watched them closely, keeping his paralo-ray gun leveled. The two boys hitched the heavy lead boxes into a more comfortable position on their shoulders and started toward the door leading outside. But neither boy thought of his discomfort or weariness now. With the explosive charge safely hidden under Tom's blouse, they had a chance to fight back. It was a small chance, perhaps, but at least a chance.

Outside, they walked slowly through the swirling methane ammonia and Tom edged closer to his unit mate.

"Can you hear me, Astro?" he whispered through the mask amplifier. The big cadet simply nodded, keeping his eyes forward.

"We'll have to bluff our way now," continued Tom in a low whisper. "This stuff has to be set off with a charge of electricity."

"Where do we get it?" mumbled Astro.

"The paralo-ray gun."

"You're space happy. It won't work."

"I know that," hissed Tom. "But maybe Miles doesn't. I'll challenge Miles, hold the stuff right in front of me, and warn him that if he fires he'll set off the explosive and blow the four of us up."

"Oh, brother. That's a bluff to end all bluffs! Suppose he doesn't bite?"

"Then get set to take another paralo-ray charge."

"O.K.," sighed Astro. "When do you want to try it?"

"I'll give you the word," replied Tom. "Just be ready." The cadet turned away quickly. "Watch it," he hissed. "He's suspicious."

The two boys plodded along across the field as Miles moved up closer. He stared at them for a long moment and then continued to walk along directly behind them.

When they reached the ship, Miles allowed them to rest and catch their breath before making the long climb up the ladder to the air-lock portal. Brett suddenly appeared in the open portal above them.

"Hey, Miles," he called, "is that the last of it?"

"Yes," Miles called back. "You get in touch with our pal?"

"Uh-huh. He's going to meet us out in space."

"In space?" Miles stared up at Brett with a strange gleam in his eye. "Why not the hide-out?"

"I don't know," Brett replied from above. "Let's not waste time talking now. Get those other two cases up here. I want to blast off."

Miles turned to the two cadets and waved his paralo-ray gun menacingly. "All right, you two. Get going!"

"Give us a few more minutes, Miles," said Tom. "We're so tired we can hardly move."

"Get up, I said," snarled the black-suited spaceman.

"I can't," whined Tom. "You'll have to give me a hand."

Miles pointed his gun straight at the young cadet. "All right. That means the big fella makes two trips and I freeze you right now."

"No, no!" cried Tom, jumping to his feet. "I can make it. Please don't freeze me again." Astro turned away to hide his smile.

Sneering his disgust at Tom's apparent fear, Miles prodded the cadets up the ladder. Tom went first, the heavy box digging into his shoulder. Astro followed, cursing the fog that prevented him from seeing where Miles stood below him so he could drop the heavy box on him.

Above them, Charles Brett watched them emerge out of the ammonia mist, ray gun held tightly in his hand. Tom climbed into the air lock safely and dropped the box on the edge of the platform, slumping to the deck beside it. Astro followed seconds later, and then Miles.

"Don't stop now," barked Miles. "Put those boxes below with the rest of them."

Tom got up slowly, leaning heavily on the outer edge of the precariously placed box. The box suddenly tilted and then slipped out of the air lock to disappear in the mist.

"Why, you clumsy—" Brett roared, raising his gun menacingly.

Astro stepped in front of Tom. "I'll get it," he cried. "Don't shoot!"

"Go on then," snarled Brett. "Go down with him, Miles. I'll stay here with Corbett."

"You go down with him," sneered Miles. "I've been up and down that ladder fifty times while you sat up here doing nothing."

"Is that so?" cried Brett angrily, turning to face the black-clad spaceman. This gave Tom the opportunity he was waiting for. He pulled the small charge of explosives from his tunic and held it in front of him.

"All right, you two!" he shouted. "Drop those paralo-ray guns. This is the booby trap you planted in the tunnel. You fire those ray guns and we all go up together."

Brett jumped back. Miles took a half step forward and stopped. "You haven't got the nerve," he sneered.

"Shoot and you'll find out," said Tom. "Go ahead! Shoot, if you've got the guts. Get down the ladder, Astro," he said. "They won't fire as long as I've got this in my hand."

Brett had begun to shake with fear but Miles brought his ray gun up slowly. He aimed it at Astro who was starting down the ladder, his head and shoulders still showing in the open air-lock portal. Tom saw what Miles was going to do. "Jump, Astro!" he shouted.

Astro jumped at the exact instant Miles fired. "Rush him," cried Miles. Brett made a headlong dash for Tom, but the cadet side-stepped at the last moment and Brett fell headlong out of the ship, wailing in sudden terror as he fell to the ground.

Miles turned to Tom. He ripped off his mask and with his free hand closed the air-lock portal.

"You fooled Brett, but you didn't fool me, Corbett." He laughed. "It takes a direct electric charge to set that stuff off. You just helped me get rid of a very obnoxious partner." He leveled his paralo-ray gun.

"I hate to do this," he said, "but it's you or me."

He fired. Tom was again frozen into that immobile state more dead than alive. Miles laughed and hurried to the control deck.

* * * * *

Astro got up on his knees slowly. Though the fall had been a hard one, he had rolled quickly with the first impact, thus preventing any injuries. He shook his head, regained his sense of direction, and then rose to his feet, starting back to the ship in hope of helping Tom. He tripped over something and fell to the ground. Groping around in the thickening ammonia gas he felt the still form of a body. For a moment, thinking it was Tom, his heart nearly stopped, and then he breathed a silent prayer of thankfulness when he recognized Charley Brett. He felt the man's heart. There was a faint beat.

Astro opened the valve on Brett's oxygen mask wide and waited until the man was breathing normally. Then he began feeling his way back to the ladder. Suddenly he heard a sound that made his blood run cold. It was the unmistakable whine of the cooling pumps building for blast-off. And he was directly underneath the exhaust tubes.

He scrambled away, heading back to the spot where Brett lay. The whining of the pumps built to an agonizing scream. There were scant seconds left to save himself. He could not wait to find Brett. He began running wildly away from the ship, stumbling, failing, rising to his feet again to plunge on, away from the deadly white-hot exhaust blast of the Space Knight.



There was a terrific explosion, and then Astro was lifted off his feet and hurled through the mist, head over heels. He screamed and then blacked out.

* * * * *

"We found him about a thousand yards away from the warehouse, Commander," said the guardsman. "He looks pretty beat and his clothes are burned a little. I think he must have been caught in the blast of that ship we heard take off."

Walters looked down at Astro's big frame, sprawled on the ground, and then at the medical corpsman who was giving him a quick examination. The corpsman straightened up and turned to Walters and Captain Strong. "He'll be all right as soon as he wakes up."

"Shock?" asked Strong.

"Yes. And complete fatigue. Look at his hands and knees. He's been doing some pretty rough work." The corpsman indicated the big cadet's hands, skinned and swollen from his labor in the mines.

"Wake him up!" growled Walters.

"Wake him up!" exclaimed the corpsman. "Why, sir, I couldn't allow—"

"Wake him up. And that's an order!" insisted Walters.

"Very well, sir. But this will have to go into my report to the senior medical officer."

"And I'll commend you for insisting on proper care for your patients," Walters stated. "But in the meantime we've got to find out what happened. And Cadet Astro is the only one who can tell us."

The corpsman turned to his emergency kit. He took out a large hypodermic needle, filled with a clear fluid, and injected it into the big cadet's arm.

In less than a minute Astro was sitting up and telling Walters everything that had happened. When he told of the pipe that was sucking off the oxygen from the main pumps, Walters dispatched an emergency crew to the mine immediately to plug the leak. Then, when Astro revealed the secret of the mine, the presence of the uranium pitchblende, Walters shook his head slowly.

"Amazing!" he exclaimed. "Greed can ruin a man. He could have declared such a discovery and still had more money than he could have spent in a lifetime."

Walters spun around. "Steve, I want the Polaris ready to blast off within an hour. We're going after one of the dirtiest space rats that ever hit the deep!"



CHAPTER 18

Roger peered around the edge of the baffling shields. The power deck was empty. He edged out and stood upright, eyes moving constantly for signs of Miles.

No longer needing the cumbersome space suit, he stripped it off and walked across the deck to the ladder. He stopped to listen again but there was only the sound of the rockets under emergency space drive. A quick glance at the control panel told him that the ship was hurtling through space at a fantastic speed. Satisfied that Miles was nowhere near, Roger gripped the rocketman's wrench tightly and began climbing slowly and cautiously.

When he reached the next deck, he raised his head through the hatch slowly. Then, in one quick movement, he pulled himself up on the deck and ran for cover behind a small locker to his right. Above him, through the open network of frames and girders, he could see the control deck, but Miles was nowhere in sight.

Something on the opposite side of the ship caught his eye. Miles' space suit hung on its rack, the heavy fish-bowllike space helmet beside it in its open locker. Roger's heart skipped a beat as he noticed the holster for a paralo-ray gun nearby. But the large flap was closed and he could not see if it held a gun.



The young cadet moved away from the protection of the locker and started toward the space suit. He moved slowly, watching the upper deck where he figured Miles would be at the control board, operating the ship.

Suddenly Miles appeared above him, walking across the open control deck with a clip board in his hand, making a standard check of the many instruments. Before Roger could find a hiding place, Miles saw the cadet. He drew his paralo-ray gun quickly, firing with the speed of a practiced hand. Roger dove toward the space suit and wrenched open the holster but found it empty. Miles was behind him now, running down the ladder.

Roger spun around, darted to the ladder leading to the power deck, and just missed being hit by Miles' second shot. He jumped the ten feet to the power deck and darted behind the huge bank of atomic motors.

Miles came down the ladder slowly, gun leveled, eyes searching the deck. He stopped with his back to the rocket motors and called, "All right, Manning, come on out. If you come out without any trouble, I won't freeze you. I'll just tie you up again."

Roger was silent, gripping the wrench tightly and praying for a chance to strike. Miles still remained in one position, protected by the motor housing.

"I'm going to count five, Manning!" he shouted. "Then I'll hunt you down and freeze you solid."

Gripping the wrench tightly and raising it above his head, Roger eased out from his hiding place and slipped across the floor lightly. He was within four feet of Miles when the black-suited spaceman spun around and stepped back quickly. "Sucker," he snarled, and fired.

Roger stood motionless, his arm still raised, the wrench falling to the deck. Miles stuck his face close to Roger's head and said, "I don't know how you got here, but it doesn't make any difference now. In a little while you and your pal, Corbett, are going for a swim out in space."

Holding Roger by the arm, he tipped the boy over and lowered him to the deck. Roger's arm stuck up like the branch of a tree. Miles stood over him, flipped on the neutralizer charge of the gun, and fired again, releasing Roger from the paralyzing effect of the ray.

The young cadet began to shake violently and through his chattering teeth he muttered a space oath. Miles only grinned.

"Just wanted you to make yourself comfortable, Manning," he said. He flipped the gun to direct charge again and pointed it at the boy. Seeing it was useless to try and jump the burly spaceman, Roger relaxed and stretched out on the deck. Miles fired again calmly, and after testing the effect of the ray with his toe, he turned to the ladder.

As the spaceman climbed back to the control deck, Roger, though in a paralyzed state, could hear the communicator loud-speaker paging Miles.

* * * * *

"Come in, Quent! This is Ross! Come in!"

Tom Corbett sat bound and gagged in the copilot's chair of the black ship, listening to Miles call again and again over the audioceiver. The fact that Miles was identifying himself as Ross puzzled the young cadet and he wondered if it was an alias. Tom was even more puzzled when Miles addressed the person he was calling as Quent.

"This is Ross! Acknowledge, Quent! Come in!"

Static spluttered over the loud-speaker and then a clear, harsh voice that was a perfect imitation, answered, "I read you, Ross," it said. "Where are you?"

Tom watched as Miles made a hasty check on the astrogation chart. "Space quadrant four," he replied. "Chart C for Charley! Where are you?"

"Same space quadrant, but on chart B for Baker," came the reply. "I think we can make visual contact on radar in above five minutes. Make the usual radar signal for identification. O.K.?"

"Good!" the Space Knight pilot replied. "What course are you on?"

There was a pause and then the voice answered, "South southwest. Speed, emergency maximum."

"Very well. I will adjust course to meet you. But what's the hurry?" asked Tom's captor.

"Better get out of space as soon as possible."

"Yeah, I guess you're right."

Tom listened intently. He closed his eyes and tried to visualize the charts and space quadrants he had heard mentioned. He knew the quadrants by heart, and knew that he was close to the asteroid belt. But each quadrant had at least a dozen or more charts, each one taking in a huge area of space.

"Is Brett with you?" asked the voice over the audioceiver.

"No. I'll tell you about it when we get together. All the rockets in space broke loose up there on Titan for a while."

"What do you mean? Hey! I think I just picked you up on my radar!" said the voice over the loud-speaker. "Give me the identification signal."

Tom watched Miles go to the radarscope and make a minute adjustment. The voice came over the loud-speaker again. "That's you, all right. Cut back to minimum speed and I'll maneuver to your space lock."

"Very well," replied the spaceman on the Space Knight.

He cut the rockets and in a matter of minutes the ship was bumped heavily as contact was made. The voice over the communicator announced the two space vessels had been coupled. "Open your air lock and come aboard."

"You come aboard my ship," said Miles. "We've got the stuff here."

"O.K. But I have to go below and wake up that jerk, Manning."

"Wake him up?"

"Yeah. I got him frozen."

"All right, make it snappy."

Miles turned to look at Tom, a sneer on his face. "I'm giving you a break, Corbett," he said. "You're going to swim with your cadet buddy. You'll have company!"

Gagged, Tom could only glare his hatred at the black-suited spaceman. In a moment he heard the air lock open below and then footsteps clattered up the ladder to the control deck.

The hatch opened and Roger stumbled inside. He saw Tom immediately and yelled, "Tom! What are—" Suddenly he stopped. He looked at the man standing beside Tom and gasped in astonishment.

Tom watched the hatch as Roger's captor stepped inside. What he saw made him twist around in his chair and stare at the man beside him, utterly bewildered.

"Twins!" cried Roger. "Identical twins."

The man stepped through the hatch and walked over to his brother. They shook hands and slapped each other on the back.

"What happened to Charley, Ross?" asked Quent Miles.

"Just a minute, Quent," replied his brother. He turned and grinned at Tom and Roger. "Surprised, huh? Don't let it bother you. We've been driving people crazy ever since we were born. Does this tell you how we won the race?"

"T-t-twin pilots," stuttered Tom in amazement. "And twin ships?"

"Exactly." Ross laughed. "Pretty smart, eh?"

"Never mind them now," snarled Quent. "I've been sitting up there on that asteroid rock talking to myself. What happened to Charley?"

"Take it easy, will you, Quent?" said Ross. "I want to have some fun." He turned to Manning. "Untie Corbett and get on the other side of the deck. Have yourselves a nice long talk before you take your last walk."

Roger slowly bent over to untie Tom, muttering a space oath under his breath. The two brothers retired to the opposite side of the control deck and sat down. Ross kept his paralo-ray pistol in his hand and never once took his eyes off the two cadets.

"Well, what happened?" demanded Quent. "What are you doing here with Corbett and where in the blazes is Charley?"

"Charley is back on Titan, and probably dead," replied Ross easily. "He wouldn't pay any attention to us when we suggested plugging up the old tunnels when we started mining that uranium, so the oxygen which we were sucking off from the main screen supply took too much. The screens started to go. Practically the whole city is flooded with ammonia gas and it's being abandoned."

Roger and Tom stood quietly, listening, and when Roger heard the news he turned to Tom with a questioning look on his face. Tom merely nodded grimly.

"But what are you doing here with this load of pitchblende?" Quent persisted.

"Everything would have been all right, even with the screens letting go," explained Ross, "if it hadn't been for Corbett and that big jerk Astro. They followed me out to the warehouse and down into the mine. Good thing we caught them, or we'd be on our way to a prison asteroid right now."

Quent glared over at Tom. "And Charley spilled the beans about the whole thing, eh?"

"Not exactly, but the Solar Guard knows enough to be suspicious," replied Ross. "We had some trouble with the radiation-detection gear and wanted to haul it out to the hide-out for Manning to check. We decided to bring out as much of the stuff as we had mined, and when we caught Corbett and Astro snooping around, we made them load the ship. Corbett, here, got smart and Astro escaped. In the fight, Charley fell out of the ship. I don't know if he got away or not."

"Do we have a whole shipload of the stuff?" asked Quent.

Ross grinned. "About two million credits' worth."

Quent rubbed his hands together. "We're in clover." He laughed and slapped his brother on the back. "Well, I suppose the Solar Guard is looking for us by now?"

Ross grinned. "Right. So we pull the old trick, eh? We have two very likely prospects right there." He pointed to Roger and Tom.

"What is that supposed to mean?" snapped Roger.

"You'll find out, squirt," sneered Quent Miles.

"Wait a minute, Quent," said Ross. "I just thought of something. No one knows there are two of us, except these two punks here. We can't work the old gag. We can only use one of them."

"How do you mean?"

"Simple. The Solar Guard thinks Manning took it on the lam from Ganymede, right?"

Quent nodded.

"Well, we take Manning, dress him up in one of our outfits and stick him aboard the empty ship alongside. The ship blows up, and should they find anything of Manning, he'll be dressed like you, or me, and that will end the situation right there. Later, we can dump Corbett out in a space suit with a little oxygen, and write a note, sticking it in his glove. When they find him, they'll think he got away from Quent Miles, and when his oxygen gave out, wrote the note giving all the details. And who can say No, since Quent Miles, as such, will be dead?"

"End to the affair!" shouted Quent. "That's perfect."

The audioceiver behind them crackled into life, and there was a clear, piercing signal, a sign that an emergency transmission was taking over all channels. The signal continued until the clear, strong voice of Commander Walters flooded the control deck of the ship.

"Attention! Attention! This is Commander Walters of the Solar Guard! Attention all Solar Guard units in space quadrants one through seven—repeat, all ships in quadrants one through seven. This is emergency alert for the rocket ship Space Knight, believed to be heading for the asteroid belt. All ships are to institute an immediate search of quadrants one through seven for the Space Knight and arrest any and all persons aboard. Repeat. All ships...."

Ross Miles rose up and snapped off the audioceiver. "Come on. We've got to get out of here!"

"What about them?" asked Quent, pointing to Roger and Tom. "Will we have time to—?"

"Plenty of time," said Ross coldly. "Blast 'em now."

"With pleasure," replied Quent Miles, taking his gun from his holster.

"Jump, Roger!" shouted Tom.

Both boys threw themselves sideways as Miles leveled his gun.

Tom plunged headlong through the hatch door and scrambled down the ladder. Roger tried to follow, but Quent fired as Roger started to jump feet first through the hatch. His body became rigid as he tumbled through the hatch. Tom looked up just in time to break his unit mate's fall, but seeing that it would be useless to stay with him, left him on the deck and turned to flee through the depths of the black ship.



CHAPTER 19

"Never mind, Manning!" shouted Quent Miles as he jumped past Roger's body. "We've got to find Corbett. Take the starboard ladder; I'll take the port. Search all the way aft to the exhaust tubes if you have to!"

Ross nodded quickly, hefted his ray gun, and moved down the opposite ladder.

Tom watched both of them come down like twin devils, hands holding the ray guns as steady as rocks. The cadet hid behind the open door leading to the lower cargo holds. Ross was the nearer of the two, walking like a cat, slowly, ready to spring or fire at the slightest movement. Tom quickly saw that if he jumped Ross, Quent would be on him in seconds. His only chance lay in their passing him, giving him the opportunity to return to the control deck and search for a ray gun for himself. And if that failed, at least he could call Commander Walters.

Ross crept closer. Tom crouched tensely. Should Ross see him, Tom would have to make an attempt to knock him out and get the ray gun before Quent could do anything.

"Careful, Quent!" called Ross as he moved toward the open hatch.

"You too," replied his brother. "This kid is plenty smart."

Tom breathed a silent prayer. Ross was now opposite the door. Should the black-suited spaceman decide to look behind it, Tom would be at his mercy.

Ross stopped beside the door and hesitated a moment.

"Hey, Ross!" Quent called, and Ross turned away from the door. "I think I hear something down inside the hold. Slip down the ladder a little way and cover me. I'll go down inside and look around. He must be down here somewhere, and if you guard the door, he can't get out."

Ross grinned. "Like flushing quail in Venus jungles," he said, moving away from the door and down into the hold where the lead boxes filled with uranium pitchblende were stored.

Tom could scarcely suppress a loud sigh of relief at his narrow escape. After a moment he peered cautiously around the edge of the door, and seeing the way clear to the control deck, ran back to the ladder. He paused at Roger's inert form and bent over, his lips close to the paralyzed cadet's ear.

"I'm going to try and find a ray gun," he whispered quickly. "If I can't, then I'm going to try and get in touch with Commander Walters or the Solar Guard patrols."

He patted the blond-haired cadet on the shoulder and raced up the ladder to the control deck. Once inside, he barred the door to the rest of the ship and began a frantic search of the many lockers and drawers. But it was fruitless. He could find no ray gun or weapon of any kind. Desperate, knowing that Ross and Quent would return to the control deck when they had searched the rest of the ship, Tom turned and scrambled up the ladder to the radar deck.

Again, barring the door behind him, he sat before the audioceiver and began calling the Polaris.

"This is Cadet Corbett aboard rocket ship Space Knight in quadrant four, chart C for Charley. Corbett aboard spaceship Space Knight in quadrant four, chart C for Charley! Come in, Commander Walters! Come in!"

Tom spun the dials on the audioceiver desperately, ranging over every circuit and repeating his cry. "This is Cadet Corbett! I am being held prisoner with Cadet Roger Manning aboard the spaceship Space Knight in space quadrant four, chart C for Charley...."

Suddenly the hum of the generators stopped and the glow of the tubes in the audioceiver died. Without a second's hesitation, Tom spun around and lunged for the door leading back to the control deck.

"They must have shut off the power," he decided. "When they didn't find me down below, they guessed that I came this way."

He raced through the control deck and down the ladder to the starboard companionway. If he could only get to the ship alongside!

He chided himself for not thinking of it before and darted toward the air lock that coupled the two ships together in space.

He turned a corner in the companionway and saw the door to the coupling chamber ahead. It was open. He dashed inside.

"Greetings, Corbett!" sneered Ross Miles. He stood just inside the doorway, the ray gun leveled at Tom.

"We figured you'd get around to thinking about the other ship sooner or later," said Quent behind him, jamming the ray gun in his back. "So we just came here and waited for you."

"Go get the other one, Quent," said Ross. Jerking Tom sideways into the coupling chamber, he rammed his gun into the curly-haired cadet's stomach. "I'll get this guy fixed aboard the other ship, and then set the firing chambers so they'll blow up."

"What are we going to do with Manning?" asked Quent.

"We'll figure that out later. Hurry up! Corbett probably called the Solar Guard."

"That's right, I did, Miles," said Tom. "They're probably closing in on you right now."

"Is that so?" snarled Quent. "Well, it's too bad you won't be alive to say hello to them."

* * * * *

"I want every pound of thrust you have on that power deck, Astro," roared Commander Walters into the intercom. "We just received word from a freighter that picked up an S O S from Tom aboard the Space Knight."

Steve Strong and Kit Barnard sat in the pilot and copilot's chairs on the control deck of the Polaris and watched the needle of the accelerometer climb as Astro poured on the power in answer to Walters' command.

"If I know Astro," said Strong, "you'll probably get the fastest ride you've ever had short of hyperdrive, Kit."

Kit Barnard gulped as he watched the needle. "I see what you mean," he said.

Walters strode up and down the deck behind the two veteran spacemen, a scowl on his face. "By the stars," he rumbled, "this is the most incredible thing I've run up against in all my years in space!"

He paced up and down several times silently. "To think that two men could—would—jeopardize the safety and lives of thousands of people for—a—a uranium mine! It's beyond my comprehension."

"Excuse me, sir," said Sid, Kit Barnard's young assistant, coming down the radar-bridge ladder. "This report just came in from Titan spaceport control."

Walters took the message and read it quickly. He grunted and handed it to Strong. "They've found the mine and the leak," he said. "The screens are working again."

"Then you'll call off the evacuation operations, sir?" asked Strong.

"Right." Walters turned to Sid. "Son, send a message back to Titan control and tell Captain Howard to stop all evacuations as soon as he has enough oxygen to provide for the citizens of Titan. And then stand by for a general order to all units in this area."

"Yes, sir," said Sid, climbing back up to the radar bridge quickly.

The three men on the control deck fell silent as the ship hurtled through space. Each of them prayed silently for Tom and Roger's safety.

On the power deck below, Astro opened every valve and adjusted the firing chambers to their emergency maximum, forcing the giant ship faster and faster through space. And when he had done all he could, he paced up and down the deck, snapping a greasy wiping rag against his thigh again and again. His face showed the concern he felt for Tom and Roger, and at the same time, there was a questioning look in his eye. The auxiliary loud-speaker of the audioceiver overhead spluttered with static. He stopped to listen.

"This is Lieutenant Frazer aboard the Solar Guard cruiser Hydra to Commander Walters!" crackled an unfamiliar voice. "Come in, Commander Walters!"

Astro stared at the loud-speaker and held his breath.

"This is Walters on the Polaris. Go ahead, Frazer!"

"I am in command of a squadron of ships on space maneuvers in quadrant five, sir. Shall I abandon my orders and proceed under your general emergency alert to search quadrant four?"

"How many ships do you have with you, Lieutenant?" asked Walters.

"Three heavy cruisers and a rocket destroyer, sir," replied the voice across the gulf of space. "And I am fully armed, sir."

"Proceed to quadrant four, Lieutenant, and seize the vessel Space Knight." There was a pause, and then Astro's blood ran cold as he heard the words, "and if necessary open fire!"

On the control deck, Captain Strong turned to Walters quickly. "But Tom and Roger, sir," he protested.

Commander Walters glared at Strong and turned back to the audioceiver. "Proceed to quadrant four," he said coldly. "Seize the vessel Space Knight, and if there is any resistance, open fire!"

* * * * *

"Did'ja hear that!" yelled Quent on the control deck of the Space Knight.



"I heard," replied Ross grimly. "With a whole squadron sweeping this quadrant we won't make it."

"What are we going to do?" asked Quent.

"We're staying right here."

"What?"

"Right here," said Ross. "Get Corbett off the other ship and set the fuses in the firing chambers to blow up after we cast off."

"But I don't see—"

"Don't ask questions!" snapped Ross. "Do as I tell you."

"O.K." Quent spun away and headed for the coupling locks that held the two ships together. Ross turned back to the ladder and flipped his ray gun on neutralizing charge, releasing Roger from the effects of the paralo ray.

The blond-haired cadet staggered to his feet shakily. "Where's Tom?" he said, clenching his teeth to keep them from rattling. "If you've done anything to him—!"

"Take it easy, Manning," growled Ross. "Just get up on the control deck and behave."

Roger glared at the spaceman, and realizing it would be useless to jump him in his weakened condition, started up the ladder. Ross followed at a careful distance.

A few minutes later Quent appeared on the control deck, forcing Tom ahead of him. "All right," he growled. "What do I do now?"

"Did you cast off the other ship?" asked Ross. And when Quent nodded, he jerked his head toward Tom and Roger and barked, "Cover them!"

As Quent stood before the two cadets, his gun leveled, Ross strode to the audioceiver and flipped it on. "This is Quent Miles to Commander Walters aboard the Polaris," he called. "Come in, Walters."

Tom and Roger looked at each other, puzzled.

"If you can hear me, Walters, this is Quent Miles. I'm surrendering to you. And you alone! Call off your squadrons and come alongside in the Polaris by yourself. If you hear me, Walters, you better do what I say, or you'll never see Manning and Corbett again." He flipped the audioceiver off and grinned at his brother. "When Walters comes aboard, he's going to get a nice surprise."

"Like what?" demanded Tom.

Ross grinned wickedly, looking very much like the devil incarnate. "You heard Walters' order to open fire, didn't you?" he said. "It seems that Space Cadets aren't worth much as hostages. But what do you think it will be like with a full-fledged commander in our hands, eh? And a rocket cruiser like the Polaris to run around in."

"You wouldn't dare kidnap Commander Walters!" exclaimed Tom.

"Oh, no." Ross laughed. "Listen, punk, with a murder charge hanging over our heads, and a couple of million credits' worth of pitchblende in the holds, both of us would do anything! And don't you forget it!" He turned to his brother. "Come on over here, Quent, and I'll tell you what we're going to do."