"Well, blast my rockets!" Roger laughed. He slung the gun over his shoulder and reached down to pick the kitten up in his arms. He began stroking its fur and making little soothing noises. He started back to the other end of his patrol post.

"You're a cute little fella," murmured Roger, nuzzling the kitten against his chin. "But you almost got blasted."

"Guard! Stand to!"

Startled, Roger whirled around to see Firehouse Tim behind him, his battered and beaten face clouded with rage. "Drop that animal at once," the petty officer roared.

Roger stooped over to let the kitten run free and it dashed away into a crack between the boxes and disappeared.

"Manning," began the enlisted spaceman, "the next time I catch you not attending to your duty, I will bring you up on charges of neglect! Carry on!" Rush spun on his heel and vanished into the darkness.

"Blasted muscle-bound squirt!" sneered Roger under his breath, shouldering his rifle and resuming his slow patrol outside the hangar.

For three weeks, Tom, Roger, and Astro, along with the three members of the Capella unit, had been spending close to eight hours a day on guard duty, eight to ten hours a day in classroom work, and the rest of the time studying. They only averaged some two to three hours of sleep per day. They were dead tired but they stuck to their task doggedly, without complaint.

Around them, the work on Professor Hemmingwell's project had proceeded with amazing speed. The tunnel promised by Dave Barret had been finished in less than five days, with the rail for the monorail spur installed overhead as each yard of the shaft was completed. In the second week, scores of cars loaded with building materials began rolling into the deserted plain several miles away from Space Academy. Then, one morning, nearly a thousand construction workers arrived and built a hangar in thirty-six hours. No sooner had the huge building been completed than a tight guard had been placed around it. Specially designed identification tags were issued to the guards and workers on the project. Gradually the huge store of cases and boxes outside the hangar had been moved inside, with all but a few of the smaller ones remaining outside. The secret work inside the hangar was advancing rapidly, but this did not enter into the thoughts of the three cadets of the Polaris unit, nor of the Capella unit. The harsh discipline instituted by Tim Rush and the extra study necessary for the end-of-year exams had forced the cadets into a round-the-clock struggle not only to keep awake but to make the class promotion lists.

Roger paced off the required distance, wheeled smartly, and in so doing came face to face with Astro, who was patrolling another side of the hangar.

"I just saw Firehouse," said Astro quietly. "Did he catch you goofing?"

"Yeah," growled Roger. "I found a kitten and he walked up just as I was holding it."

Astro grinned. "I wouldn't be surprised if that pocket-sized giant didn't send that cat down there to tempt you."

"How's Tom?" asked Roger. Astro, in his patrol, came in contact with both unit mates.

"Sleepy. He's having a tough time with that chapter on space law. He didn't sleep at all last night."

"He better keep awake," said Roger. "That little fireman's got his rockets hot tonight. He'll blast Tom sure if—"

"Wait a minute," said Astro suddenly, looking off into the darkness. "What was that?"

Roger spun around, his rifle in his hands, ready to fire. "What is it?" he asked.

"I don't know," replied Astro in a whisper. "I thought I saw something move inside the hangar." He pointed to a large window. "Sort of a shadow against the frosted glass."

"Are you sure?"

"Of course I'm sure."

"I'll investigate. You get Tom and call Firehouse."

"Right," replied Astro, and raced down the path, alongside the hangar.

Grasping his rifle firmly, Roger inched toward a nearby door. He opened it a crack, then flattened himself against the wall and watched Astro run toward the other end of the hangar. He saw the big Venusian say a few quick words to Tom and then rush off toward the guardhouse and the communicator. Tom waved to Roger, indicating that he would enter the opposite door of the hangar.

Roger dropped to his hands and knees and poked his head through the open door, peering around from one end of the huge dark chamber to the other. Then, taking a deep breath, he rose and stepped quickly inside. He closed the door behind him and stood still, listening for some sound.

Suddenly there was a flash of light from the opposite wall. Roger brought the paralo-ray gun up to his shoulder quickly and was about to fire when he realized that the light he saw was Tom opening the door on the opposite side. He breathed easier and waited until he could distinguish Tom's moving figure clearly, and then walked stealthily forward on a parallel line.

It was the first time Roger had been inside the hangar since it had been constructed and he was not sure of his way around, but gradually, the moonlight filtering in through the frosted plates of Titan crystal illuminated the huge forms of the machines around him.

He stopped and gasped. Without even realizing it, he emitted a long whistle of astonishment. Before him, reaching up into the shadows of the cavernous hangar, was the gleaming hull of a huge rocket ship. Two hundred feet long, the space vessel stood on its stabilizer fins, ladders and cables running into the open ports on both sides.

Roger waved to Tom, who had also stopped to stare at the giant spaceship, and the two of them met beneath the gleaming hull.

"What's the matter?" asked Tom. "Astro said you saw someone."

"I didn't see a blasted thing," said Roger in an exasperated whisper. "That big goof said he did."

"Wow!" said Tom, looking up at the ship. "This is some baby. I never saw one with lines like that before. Look at the funny bulges on the lower side of the hull."

"Sh!" hissed Roger. "I just heard something."

The two cadets stood silently, ears cocked for the slightest sound in the huge hangar. They heard a distinct tapping sound from somewhere above them.

"It's coming from inside the ship!" said Tom.

"You climb in the other port," said Roger. "I'll take this one."

"Right," said Tom. "And remember, if there's any trouble, shoot first and ask questions later."

"Check."

Tom slipped away from Roger and moved to the opposite side of the ship. Slinging the rifle over his shoulder, he climbed up the ladder silently toward the open port.

Making his way noiselessly through the air lock, he entered the huge main deck of the ship and was able to see his way around by the faint glow of the emergency reflectors in the bulkheads. Tiny, sparkling gemlike pieces of specially coated Titan crystal, they glowed with steady intensity for many hours after having been exposed to any form of light. The deck was a mass of cables, boxes, tools, and equipment. Tom noticed curious-looking machines behind, what he judged to be, the odd bulges on the outside of the hull. Ahead of him, a hatch was partially open and he could see light streaking through the opening. He gripped his rifle tightly, finger on the trigger, and moved forward.

At the hatch he paused and looked into the next compartment. From the opposite side, he saw another hatch partially open and the outline of Roger's head and shoulders. Between them, a man was bending over a makeshift desk, copying information from a calculator and a set of blueprints. Tom nodded across to Roger and they both stepped into the compartment at the same time.

"Put up your hands, mister, or I'll freeze you so hard it'll take a summer on the Venus equator to warm you up," Roger drawled.

The man jerked upright, stumbled back from the desk, and moved toward Tom, keeping his eyes on Roger. He backed into the barrel of Tom's ray gun and stopped, terrified. He threw up his hands.

"What—wh—" he stammered and then caught himself. "How dare you do this to me?" he demanded.

"Shut up!" snapped Tom. "What are you doing here?"

"None of your business," the man replied.

"I'm making it my business," snapped Tom, pressing the gun into the man's back. "Who are you and how did you get in here?"

The man turned and looked Tom in the eye. "I have a right to be here," he stated coldly. "I'll show you my identification—" He brought his hands down and reached into his jacket, but Roger stepped over quickly and brought the barrel of his gun down sharply on the man's head. He slumped to the floor with a groan and was still.

"What did you do that for?" growled Tom.

Roger didn't reply. He reached down into the unconscious man's jacket and pulled out a small paralo-ray gun stuck in the top of his waistband. "Some identification," Roger drawled.

"Thanks, pal," said Tom sheepishly. "Let's search him. Maybe we can find out who he is."

As Roger bent over the fallen man, there was a commotion in the hangar outside the ship, followed by the sound of footsteps clattering up the ladders to the ports. Seconds later, Astro, followed by Tim Rush and a squad of enlisted spacemen, surged into the compartment. Rush stopped short when he saw the man on the floor.

"Great jumping Jupiter," gasped the petty officer, then whirled on Tom and Roger. "You space-blasted idiots!" he shouted. "You good-for-nothing harebrained, moronic dumbbells! Do you know what you've done?"

Tom and Roger stared at each other in amazement. Astro, standing to one side, looked confused.

"Sure we know what we've done," declared Tom. "We found this guy in here copying secrets from some blueprints there on the desk and—"

"Copying secrets!" screamed Rush. "Why, you ding-blasted idiots, that's Dave Barret, the supervisor of this whole project!"

The man on the floor stirred and Firehouse ordered the squad of enlisted men to help him up. Just then, there was a bellow of rage from the hatch. Major Connel stepped into the compartment, his face a mask of disgust and anger.

"By the rings of Saturn!" he roared. "I've been sitting in the laboratory for the last hour and a half waiting for Dave Barret to come back with vital information, so we could get on with our experiments, and I find that you—you—" Connel was so furious, he could hardly talk.

He faced the three cadets. "There isn't anything in the books that says you should be disciplined for this—this—outrage, but believe me, Cadets"—his voice sounded like thunder in the small compartment—"this is the very last time I'll stand for this kind of stupidity."

Tom gulped but stepped forward bravely. "Sir," he said clearly, "I would like respectfully to submit the facts for the major's honest consideration. Neither of us has ever seen this man before and we found him copying information from these blueprints. When I challenged him, he said he was going to show us his identification. He put his hands in his jacket to get it, but Roger saw a gun in his belt, and thinking he was going to use it, Roger hit him on the head." Tom stopped, clamped his mouth shut, and stared the major in the eye. "That's all, sir."

Connel returned the stare, his eyes meeting those of the cadet for a full half minute. "All right," he said finally. "I guess it's just a case of misjudgment. But," he added scathingly, "in the face of the Polaris unit's record, you can understand my initial opinion."

As Dave Barret was assisted from the ship by the guards, Connel turned to Rush. "Firehouse!" he barked.

"Yes, sir?"

"See that these cadets don't cause any more mischief."

"Yes, sir."

"Dismissed," snapped Connel.

"All right, you space brats," bellowed Rush, "back to your patrol!"

Tom, Roger, and Astro left the ship and returned to their posts outside the hangar. Just before they separated to resume their endless march around the hangar, Tom winked at his unit mates. "At least we didn't get demerits," he said.

"Only because Connel couldn't find any reason to give them to us," sneered Roger. "What a busted rocket he's getting to be!"

"Yeah," agreed Astro quietly.

The three cadets began their round again, their eyes heavy with lack of sleep, their arms and legs leaden, and their desire to become successful Space Cadets more determined than ever. But they didn't know they had started a chain reaction that would affect their very lives.