Commission.

When blastoff time came for the Valhalla, Steve had not reported back from the Starmen's Enclave where all Spacers lived during in-port stays.

Alan's memories of the scene were still sharp. Captain Donnell had been conducting check-off, making sure all members of the Crew had reported back and were aboard. This was a vital procedure; in case anyone were accidentally left behind, it would mean permanent separation from his friends and family.

He had reached the name Donnell, Steve. No answer came. Captain Donnell called his name a second time, then a third. A tense silence prevailed in the Common Room of the starship, where the Crew was assembled.

Finally Alan made himself break the angry silence. "He's not here, Dad. And he's not coming back," he said in a hesitant voice. And then he had had to explain to his father the whole story of his unruly, aggressive twin brother's plan to jump ship—and how Steve had tried to persuade him to leave the Valhalla too.

Steve had been weary of the endless shuttling from star to star, of forever ferrying colonists from one place to another without ever standing on the solid ground of a planet yourself for more than a few days here, a week there.

Alan had felt tired of it too—they all did, at some time or another—but he did not share his twin's rebellious nature, and he had not gone over the hill with Steve.

Alan remembered his father's hard, grim expression as he had been told the story. Captain Donnell's reaction had been curt, immediate, and thoroughly typical: he had nodded, closed the roll book, and turned to Art Kandin, the Valhalla's First Officer and the Captain's second-in-command.

"Remove Crewman Donnell from the roster," he had snapped. "All other hands are on board. Prepare for blastoff."

Within the hour the flaming jets of the Valhalla's planetary drive had lifted the great ship from Earth. They had left immediately for Alpha Centauri, four and a half light-years away. The round trip had taken the Valhalla just six weeks.

During those six weeks, better than nine years had passed on Earth.

Alan Donnell was seventeen years old.

His twin brother Steve was now twenty-six.

"Happy rising, Alan," called a high, sharp voice as he headed past the blue-painted handholds of Gravity Deck 12 on his way toward the mess hall.

Startled, he glanced up, and then snorted in disgust as he saw who had hailed him. It was Judy Collier, a thin, stringy-haired girl of about fourteen whose family had joined the Crew some five ship-years back. The Colliers were still virtual newcomers to the tight group on the ship—the family units tended to remain solid and self-contained—but they had managed to fit in pretty well by now.

"Going to eat?" she asked.

"Right enough," said Alan, continuing to walk down the plastifoam-lined corridor. She tagged along a step or two behind him.

"Today's your birthday, isn't it?"

"Right enough," Alan said again, more abruptly. He felt a sudden twinge of annoyance; Judy had somehow developed a silly crush on him during the last voyage to Alpha C, and since then she had contrived to follow him around wherever he went, bombarding him with questions. She was a silly adolescent girl, Alan thought scornfully.

"Happy birthday," she said, giggling. "Can I kiss you?"

"No," returned Alan flatly. "You better watch out or I'm going to get Rat after you."

"Oh, I'm not afraid of that little beast," she retorted. "One of these days I'll chuck him down the disposal hatch like the little vermin he—ouch!"

"You watch out who you're calling vermin," said a thin, dry, barely-audible voice from the floor.

Alan glanced down and saw Rat, his pet and companion, squatting near Judy and flicking his beady little red eyes mischievously in the direction of the girl's bare skinny ankle.

"He bit me," Judy complained, gesturing as if she were going to step on the little creature. But Rat nimbly skittered to one side, leaped to the trousers of Alan's uniform, and from there clambered to his usual perch aboard his master's shoulder.

Judy gestured at him in frustration, stamped her foot, and dashed away into the mess hall. Chuckling, Alan followed and found his seat at the bench assigned to Crewmen of his status quotient.

"Thanks, fellow," he said softly to the little being on his shoulder. "That's kid's getting to be pretty annoying."

"I figured as much," Rat said in his chittering birdlike voice. "And I don't like the way she's been looking at me. She's just the kind of individual who would dump me in a disposal hatch."

"Don't worry about it," Alan said. "If she pulls anything of the sort I'll personally see to it that she goes out right after you."

"That does me a lot of good," Rat said glumly as Alan's breakfast came rolling toward him on the plastic conveyor belt from the kitchen.

Alan laughed and reached avidly for the steaming tray of food. He poured a little of his synthorange juice into a tiny pan for Rat, and fell to.

Rat was a native of Bellatrix VII, an Earth-size windswept world that orbited the bright star in the Orion constellation. He was a member of one of the three intelligent races that shared the planet with a small colony of Earthmen.

The Valhalla had made the long trip to Bellatrix, 215 light-years from Earth, shortly before Alan's birth. Captain Donnell had won the friendship of the little creature and had brought him back to the ship when time came for the Valhalla to return to Earth for its next assignment.

Rat had been the Captain's pet, and he had given Alan the small animal on his tenth birthday. Rat had never gotten along well with Steve, and more than once he had been the cause of jealous conflicts between Alan and his twin.

Rat was well named; he looked like nothing so much as a small bluish-purple rodent, with wise, beady little eyes and a scaly curling tail. But he spoke Terran clearly and well, and in every respect he was an intelligent, loyal, and likable creature.

They ate in silence. Alan was halfway through his bowl of protein mix when Art Kandin dropped down onto his bench facing him. The Valhalla's First Officer was a big pudgy-faced man who had the difficult job of translating the concise, sometimes almost cryptic commands of Alan's father into the actions that kept the great starship going.

"Good rising, Alan. And happy birthday."

"Thanks, Art. But how come you're loafing now? Seems to me you'd be busy as a Martian dustdigger today, of all days. Who's setting up the landing orbit, if you're here?"

"Oh, that's all been done," Kandin said lightly. "Your Dad and I were up all last night working out the whole landing procedure." He reached out and took Rat from Alan's shoulder, and began to tickle him with his forefinger. Rat responded with a playful nip of his sharp little teeth. "I'm taking the morning off," Kandin continued. "You can't imagine how nice it's going to be to sit around doing nothing while everyone else is working, for a change."

"What's the landing hour?"

"Precisely 1753 tonight. It's all been worked out. We actually are in the landing orbit now, though the ship's gimbals keep you from feeling it. We'll touch down tonight and move into the Enclave tomorrow." Kandin eyed Alan with sudden suspicion. "You're planning to stay in the Enclave, aren't you?"

Alan put down his fork with a sharp tinny clang and stared levelly at the First Officer. "That's a direct crack. You're referring to my brother, aren't you?"

"Who wouldn't be?" Kandin asked quietly. "The captain's son