"What!" exclaimed Major Connel. "Give me that again."

The messenger from the Solar Guard headquarters on Mars repeated the message. "Cadet Corbett has not been in his hotel since last night, sir," he said. "He was seen leaving the service entrance at about 2100 hours. There is no report as to his whereabouts, sir."

Standing at the foot of the ladder leading to the main air lock of the Polaris, Major Connel turned to Carter Devers angrily.

"This is the end!" he shouted. "I've had as much of this foolishness as I'm going to take. When that young space brat comes back, I'm going to throw the book at him."

"Now, now, Major," said Devers. "I wouldn't be too hard on the lad. How do you know that he isn't in some kind of trouble?"

"That's just it," growled Connel. "One of those three is always in trouble."

"He saved your life," reminded Devers.

"I'm well aware of that," replied Connel stiffly. "But it's a personal debt. It has nothing to do with his behavior as a cadet. I ordered him to go to that hotel and rest, not go skylarking all over Marsport. This is typical of the whole unit's attitude."

"But you said that they were the best crew you ever had," insisted Devers.

"I know, but what's worse is that they know it! Blast it, Carter, it isn't easy to say the things I've said about Corbett! He's a fine lad. But look at it this way. I have to return to Atom City immediately. Corbett may be in trouble, right?" Devers nodded. "Well, how do you think I feel, blasting off and leaving him?"

Devers nodded his understanding as Connel continued furiously, "And furthermore, I have more important things to think about than wet-nursing a cadet."

At that moment Connel noticed a jet car racing across the spaceport toward the Polaris. As it drew near, he saw the insigne of the Solar Guard on the hood. His eyes widened hopefully for a second. "Humph," he grunted, "this may be him now!"

"If it is," cautioned Devers, "go easy on the boy."

"We'll see, we'll see."

The car screamed to a stop in front of them, the plastic blister was thrown back, and another Solar Guard messenger climbed out, saluting Connel smartly.

"Message from Solar Guard headquarters, Major Connel," he said.

Connel took the paper and ripped it open. "Excuse me, Carter," he muttered and stepped to one side to read the note hurriedly.

Dashing up the metal ladder, Connel roared the order to the waiting ground crew. "Stand by to blast off."

Carter Devers scrambled up into the giant ship after the Solar Guard officer, and in less than a minute later, all ports were sealed and the Polaris was ready for space. In the pilot's chair, Connel called traffic control for blast-off, and at the same time prepared to raise ship.

By the time Devers had strapped himself into the copilot's chair next to Connel, the ship was quivering with leashed power. Suddenly Connel roared the familiar call for space.

"Blast off, minus five, four, three, two, one, zero!"

The great ship literally exploded off the ground, and within seconds, was rocketing through the thin atmosphere above Mars on course for Earth, far across the deep black velvet void of space, but leaving Tom Corbett, her true commander, behind.

Captain Steve Strong and Commander Walters watched grimly as the Polaris landed on the Academy spaceport. They had been in contact with Connel during his trip back to Earth and had already told the bluff major of still another incident that had taken place at the Academy while he was gone.

Roger and Astro had stolen a rocket scout and disappeared.

"I don't get it, sir," sighed Strong. "Manning and Astro blowing wide open, Corbett disappearing—" He shook his head. "It doesn't make sense."

"Perhaps not," said Walters. "But those three are really in trouble now. Connel won't stand for this kind of behavior."

"Do you think that he'll go so far as to ask for a court-martial?"

Walters hesitated. "I hate to say this, Steve," he said finally, "but if Major Connel doesn't, I will be forced to. No other unit has had more of an opportunity to prove itself than the Polaris unit. And every time, something like this happens."

"But suppose they have good explanations," insisted Strong.

"It would have to be better than anything they've had before," replied Walters. "Frankly, I cannot see how that is possible."

Walters climbed into his jet car and Strong followed, biting his lip.

The car shot across the field to the now grounded Polaris, pulling alongside it just as Major Connel and Carter Devers climbed out of the open hatch. Without even the courtesy of a greeting, Connel roared, "What's this about those two cadets stealing a ship?"

"Let's talk about that later, Lou," said Walters. "Climb in. We've got something more important to discuss. The saboteur."

Devers stepped forward. "This is no place for me, I know," he said. "I'll leave you here. And thanks for the lift, Major."

Connel grunted his acknowledgment and climbed into the car as Strong turned to Devers.

"There was a message for you, Mr. Devers," said the Solar Guard captain. "You're to get in touch with your Atom City office immediately."

"Thanks, Steve," said Devers, and with a wave of his hand to the others walked away.

As the jet car raced back to the Tower of Galileo, Walters brought Connel up to date on the incident at the hangar leading to the arrest of Pat Troy. When they reached Walters' office, high in the tower, Troy was ushered in by two guards.

"Sit down!" barked Connel, taking command of the situation.

Troy walked to the center of the room and sat down in the indicated chair, facing Walters, Connel, and Strong.

"We'd like to get to the bottom of this as soon as possible, Troy," began Connel. "So I suggest that you tell us the truth and save us the trouble of pulling it out of you.

"I will answer all of your questions to the best of my ability, sir," said Troy calmly. "And I will tell the truth at all times."

"Very well," snorted Connel. "Now, who are you working for?"

"Professor Hemmingwell," replied Troy.

"Stow that," snarled Connel. "Who paid you to sabotage the ship?"

"I have not committed any sabotage for anyone, sir."

"Then you deny that you wrecked that firing unit?"

"Yes."

Walters suddenly leaned forward. "But you do not deny that you knew about the special unit that Professor Hemmingwell had created," he said. "A unit that only he and I knew about?"

"I knew about the unit—yes, sir," replied Troy.

"How could you?" demanded Walters.

"I overheard you both discussing it one day."

"Where?"

"In the hangar," said Troy. "You and Professor Hemmingwell were talking on the main deck while I was inside—what will be the radar deck—working. I heard you talking about the unit, and after you left, I happened to find a blueprint on the table. It coincided with what you had been talking about. I looked at it and then thought nothing of it. A few minutes later the professor came running in and took the blueprint away."

"Did he ask you if you had read the print?" asked Connel.

"No, sir," replied Troy. "If he had, I would have told him that I had."

"Now," said Connel, "did you have anything to do with the so-called accident to the oscillating timing device?"

"No, sir."

"Do you know who did?"

"No, sir."

"We can put you under drugs, you know, and get the truth out of you," warned Connel.

"You'll get the same answer, sir," Troy calmly replied.

Walters, Strong, and Connel moved to one side of the room and talked in low tones while Troy remained seated.

"Well," said Walters, "do we give him drugs or not?"

"I may be sticking my neck out, Commander," said Steve, "but I think that he's telling the truth."

"Same here," said Connel. "I would suggest that we let him loose, and even let him go back to work, but keep an eye on him."

"And you wouldn't give him drugs now?"

"No. I'd give the benefit of the doubt to a man any time," said the hardened space major.

"All right," said Walters. He turned back and told Troy he was free, but that he was not to leave the restricted area. And he was only permitted to work on less critical projects. "Do you have anything to say?" Walters asked.

Troy smiled at them and shook his head. "No, sir. That's fine with me," he said. "And I'll keep my eye open for the real saboteur—"

"That won't be necessary!" snapped Connel. "We're capable of handling our own detective work."

Troy grinned again. "Very well, sir," he said.

Connel dismissed the guards and the foreman walked out of the office a free man.

Connel and Walters turned to discussing the installation of the receivers on Mars, with Connel lauding young Lieutenant Slick highly. "That boy deserves a promotion in rank," he stated.

Walters nodded. "I'll put his name on the list at the end of the year," he said. "If he has done everything you say he has, he deserves it."

Steve Strong stood to one side, waiting impatiently for the two older men to finish their conversation before asking about Tom Corbett. At the same time, he was a little fearful of bringing up the subject of the Polaris unit, in the face of what Astro and Roger had just done. It was not an easy thing to do, but at the first opportunity he broke into the conversation with a direct question to Connel.

"Major, is there any doubt in your mind about Corbett's disappearance being an accident or do you—"

Connel cut him off. "Do I think he's AWOL?"

Strong nodded silently.

"Steve," said Connel patiently, "I know how you feel about those three boys, but tell me, how long can this go on? They constantly take off on their own, without authorization—"

"But they usually have a good reason," Strong interrupted quickly.

"Then why don't they give us the reason first?" Connel shot back.

"What Lou is trying to say," interjected Walters quietly, "is that Corbett, Manning, and Astro have time and time again committed us to take action, to get them out of situations that they initiated. It's time they were stopped! They are only one unit in this Academy, not the whole works."

"Then I guess you mean"—Strong hesitated, a lump in his throat—"it will be the end of the unit when they get back?"

"If they get back," snapped Connel, "I intend to see that all three receive solid disciplinary action."

"Very well, Major," said Strong. He rose and addressed the commander. "I request permission for emergency leave, sir, commencing now."

"Permission denied!" said Walters. "This is exactly what I've been talking about, Steve. You want to leave to go to Mars and look for Tom when we need you here on the project."

Strong's face suddenly turned white. And then, for the first time in his career, he ignored military courtesy and turned to leave without the courtesy of a salute or permission to do so. Connel almost called him back, but Commander Walters put a restraining hand on the major's arm.

"Think of it this way, Lou," he said. "If you wanted something you believed to be right, and it was denied you, how would you feel?"

"I'd very likely do the same thing," snapped the major. "And I'd get my rockets busted for it by my commanding officer!"

Walters grinned and pulled the major back to the desk where they continued their discussion of the receivers on Mars.

They had no sooner begun their discussion when the sliding door opened and Professor Hemmingwell burst into the room, his smock flying behind him, his hair ruffled and eyes wide with fright.

"The ship! The ship!" he cried out. "Someone has blown up the whole control panel of the ship!"