Any variable can be shaded by human judgment; an intuitive projection by a human operator can save his ship -- or lose it. A paralysis beam travels at speed-of-light; torpedoes never have time to get up to more than a few hundred kilometers per second -- yet it is possible for a raider to come within beaming range, have his pencil of paralyzing radiation on its way, and the trader to launch a target-seeker before the beam strikes... and still be saved when the outlaw flames into atomic mist a little later.

But if the operator is too eager by a few seconds, or overly cautious by the same, he can lose his ship. Too eager, the missile will fail to reach target; too cautious, it will never be launched.

Seasoned oldsters are not good at these jobs. The perfect firecontrolman is an adolescent, or young man or woman, fast in thought and action, confident, with intuitive grasp of mathematical relations beyond rote and rule, and not afraid of death he cannot yet imagine.

The traders must be always alert for such youngsters; Thorby seemed to have the feel for mathematics; he might have the other talents for a job something like chess played under terrific pressure and a fast game of spat ball. His mentor was Jeri Kingsolver, his nephew and roommate. Jeri was junior in family rank but appeared to be older; he called Thorby "Uncle" outside the computer room; on the job Thorby called him "Starboard Senior Firecontrolman" and added "Sir."

During long weeks of the dive through dark toward Losian, Jeri drilled Thorby. Thorby was supposed to be training for hydroponics and Jeri was the Supercargo's Senior Clerk, but the ship had plenty of farmers and the Supercargo's office was never very busy in space; Captain Krausa directed Jeri to keep Thorby hard at it in the computer room.

Since the ship remained at battle stations for half a week while boosting to speed-of-light, each fighting station had two persons assigned watch-and-watch. Jeri's junior controlman was his younger sister Mata. The computer had twin consoles, either of which could command by means of a selector switch. At General Quarters they sat side by side, with Jeri controlling and Mata ready to take over.

After a stiff course in what the machine could do Jeri put Thorby at one console, Mata at the other and fed them problems from the ship's control room. Each console recorded; it was possible to see what decisions each operator had made and how these compared with those made in battle, for the data were from records, real or threatened battles in the past.

Shortly Thorby became extremely irked; Mata was enormously better at it than he was.

So he tried harder and got worse. While he sweated, trying to outguess a slave raider which had once been on Sisu's screens, he was painfully aware of a slender, dark, rather pretty girl beside him, her swift fingers making tiny adjustments among keys and knobs, changing a bias or modifying a vector, herself relaxed and unhurried. It was humiliating afterwards to find that his pacesetter had "saved the ship" while he had failed.

Worse still, he was aware of her as a girl and did not know it -- all he knew was that she made him uneasy.

After one run Jeri called from ship's control, "End of drill. Stand by." He appeared shortly and examined their tapes, reading marks on sensitized paper as another might read print. He pursed his lips over Thorby's record. "Trainee, you fired three times... and not a one of your beasts got within fifty thousand kilometers of the enemy. We don't mind expense -- it's merely Grandmother's blood. But the object is to blast him, not scare him into a fit. You have to wait until you can hit"

"I did my best!"

"Not good enough. Let's see yours, Sis."

The nickname irritated Thorby still more. Brother and sister were fond of each other and did not bother with titles. So Thorby had tried using their names... and had been snubbed; he was "Trainee," they were "Senior Controlman" and "Junior Controlman." There was nothing he could do; at drill he was junior. For a week, Thorby addressed Jeri as "Foster Ortho-Nephew" outside of drills and Jeri had carefully addressed him by family title. Then Thorby decided it was silly and went back to calling him Jeri. But Jeri continued to call him "Trainee" during drill, and so did Mata.

Jeri looked over his sister's record and nodded. "Very nice, Sis! You're within a second of post-analyzed optimum, and three seconds better than the shot that got the so-and-so. I have to admit that's sweet shooting... because the real run is my own. That raider off Ingstel... remember?"

"I certainly do." She glanced at Thorby.

Thorby felt disgusted. "It's not fair!" He started hauling at safety-belt buckles.

Jeri looked surprised. "What, Trainee?"

"I said it's not fair! You send down a problem, I tackle it cold -- and get bawled out because I'm not perfect. But all she had to do is to fiddle with controls to get an answer she already knows... to make me look cheap!"

Mata was looking stricken. Thorby headed for the door. "I never asked for this! I'm going to the Captain and ask for another job."

"Trainee!"

Thorby stopped. Jeri went on quietly. "Sit down. When I'm through, you can see the Captain -- if you think it's advisable."

Thorby sat down.

"I've two things to say," Jeri continued coldly. "First --" He turned to his sister. "Junior Controlman, did you know what problem this was when you were tracking?"

"No, Senior Controlman."

"Have you worked it before?"

"I don't think so."

"How was it you remembered it?"

"What? Why, you said it was the raider off Ingstel. I'll never forget because of the dinner afterwards -- you sat with Great Grandmo -- with the Chief Officer."

Jeri turned to Thorby. "You see? She tracked it cold... as cold as I had to when it happened. And she did even better than I did; I'm proud to have her as my junior tracker. For your information, Mister Stupid Junior Trainee, this engagement took place before the Junior Controlman became a trainee. She hasn't even run it in practice. She's just better at it than you are."

"All right," Thorby said sullenly. "I'll probably never be any good. I said I wanted to quit."

"I'm talking. Nobody asks for this job; it's a headache. Nobody quits it, either. After a while the job quits him, when post-analysis shows that he is losing his touch. Maybe I'm beginning to. But I promise you this: you'll either learn, or I will go to the Captain and tell him you don't measure up. In the meantime... if I have any lip out of you, I'll haul you before the Chief Officer!" He snapped, "Extra drill run. Battle stations. Cast loose your equipment." He left the room.

Moments later his voice reached them. "Bogie! Starboard computer room, report!"

The call to dinner sounded; Mata said gravely, "Starboard tracker manned. Data showing, starting run." Her fingers started caressing keys. Thorby bent over his own controls; he wasn't hungry anyhow. For days Thorby spoke with Jeri only formally. He saw Mata at drill, or across the lounge at meals; he treated her with cold correctness and tried to do as well as she did. He could have seen her at other times; young people associated freely in public places. She was taboo to him, both as his niece and because they were of the same moiety, but that was no bar to social relations.

Jeri he could not avoid; they ate at the same table, slept in the same room. But Thorby could and did throw up a barrier of formality. No one said anything -- these things happened. Even Fritz pretended not to notice.

But one afternoon Thorby dropped into the lounge to see a story film with a Sargonese background; Thorby sat through it to pick it to pieces. But when it was over he could not avoid noticing Mata because she walked over, stood in front of him, addressed him humbly as her uncle and asked if he would care for a game of spat ball before supper?