The Fourth Profession

“Why the big deal, Frazer? I thought you already knew.”

“No. This is the first I’ve heard of it. I don’t read the Sunday supplements.”

Morris was exasperated. “But you knew enough to call the laser cannon a launching laser!”

“I just now realized why it’s called that.”

Morris stared at me for several seconds. Then he said, “You got it out of the Monk language course.”

“I guess so.”

He got back to business. “The newspapers gave poor Finney a terrible time. You didn’t see the political cartoons either? Too bad. But when the Monk ship got closer it started sending signals. It was an interstellar sailing ship, riding the sunlight on a reflecting sail, and it was coming here.”

“Signals. With dots and dashes? You could do that just by tacking the sail.”

“You must have read about it.”

“Why? It’s so obvious.”

Morris looked unaccountably ruffled. Whatever his reasons, he let it pass. “The sail is a few molecules thick and nearly five hundred miles across when it’s extended. On light pressure alone they can build up to interstellar velocities—but it takes them a long time. The acceleration isn’t high.

“It took them two years to slow down to solar system velocities. They must have done a lot of braking before our telescopes found them, but even so they were going far too fast when they passed Earth’s orbit. They had to go inside Mercury’s orbit and come up the other side of the sun’s gravity well, backing all the way, before they could get near Earth.”

I said, “Sure. Interstellar speeds have to be above half the speed of light, or you can’t trade competitively.”

“What?”

“There are ways to get the extra edge. You don’t have to depend on sunlight, not if you’re launching from a civilized system. Every civilized system has a moon-based launching laser. By the time the sun is too far away to give the ship a decent push, the beam from the laser cannon is spreading just enough to give the sail a hefty acceleration without vaporizing anything.”

“Naturally,” said Morris, but he seemed confused.

“So that if you’re heading for a strange system, you’d naturally spend most of the trip decelerating. You can’t count on a strange system having a launching laser. If you know your destination is civilized, that’s a different matter.”

Morris nodded.

“The lovely thing about the laser cannon is that if anything goes wrong with it, there’s a civilized world right there to fix it. You go sailing out to the stars with trade goods, but you leave your launching motor safely at home. Why is everybody looking at me funny?”

“Don’t take it wrong,” said Morris. “But how does a paunchy bartender come to know so much about flying an interstellar trading ship?”

“What?” I didn’t understand him.

“Why did the Monk ship have to dive so deep into the solar system?”

“Oh, that. That’s the solar wind. You get the same problem around any yellow sun. With a light-sail you can get push from the solar wind as well as from light pressure. The trouble is, the solar wind is just stripped hydrogen atoms. Light bounces from a light-sail, but the solar wind just hits the sail and sticks.”

Morris nodded thoughtfully. Louise was blinking as if she had double vision.

“You can’t tack against it. Tilting the sail does from nothing. To use the solar wind for braking you have to bore straight in, straight toward the sun,” I explained.

Morris nodded. I saw that his eyes were as glassy as Louise’s eyes.

“Oh,” I said. “Damn, I must be stupid today. Morris, that was the third pill.”

“Right,” said Morris, still nodding, still glassy-eyed. “That must have been the unusual, really unusual profession you wanted. Crewman on an interstellar liner. Jesus.”

And he should have sounded disgusted, but he sounded envious.

His elbows were on the table, his chin rested on his fists. It is a position that distorts the mouth, making one’s expression unreadable. But I didn’t like what I could read in Morris’s eyes.

There was nothing left of the square and honest man I had let into my apartment at noon. Morris was a patriot now, and an altruist, and a fanatic. He must have the stars for his nation and for all mankind. Nothing must stand in his way. Least of all, me.

Reading minds again, Frazer? Maybe being captain of an interstellar liner involves having to read the minds of the crew, to be able to put down a mutiny before some idiot can take a heat point to the mpff glip habbabub, or however a Monk would say it; it has something to do with straining ketones out of the breathing-air.

My urge to acrobatics had probably come out of the same pill. Free fall training. There was a lot in that pill.

This was the profession I should have hidden. Not the Palace Torturer, who was useless to a government grown too subtle to need such techniques; but the captain of an interstellar liner, a prize too valuable to men who have not yet reached beyond the Moon.

And I had been the last to know it. Too late, Frazer.

“Captain,” I said. “Not crew.”

“Pity. A crewman would know more about how to put a ship together. Frazer, how big a crew are you equipped to rule?”

“Eight and five.”

“Thirteen?”

“Yes.”

“Then why did you say eight and five?”

The question caught me off balance. Hadn’t I… ? Oh. “That’s the Monk numbering system. Base eight. Actually, base two, but they group the digits in threes to get base eight.”

“Base two. Computer numbers.”

“Are they?”

“Yes. Frazer, they must have been using computers for a long time. Eons.”

“All right.” I noticed for the first time that Louise had collected our glasses and gone to make fresh drinks. Good, I could use one. She’d left her own, which was half full. Knowing she wouldn’t mind, I took a swallow.

It was soda water.

With a lime in it. It looked just like our gin and tonics. She must be back on the diet. Except that when Louise resumed a diet, she generally announced it to all and sundry…

Morris was still on the subject. “You use a crew of thirteen. Are they Monk or human or something else?”

“Monk,” I said without having to think.

“Too bad. Are there humans in space?”

“No. A lot of two-feet, but none of them are like any of the others, and none of them are quite like us.”

Louise came back with our drinks, gave them to us, and sat down without a word.

“You said earlier that a species that can’t develop space flight is no better than animals.”

“According to the Monks,” I reminded him.

“Right. It seems a little extreme even to me, but let it pass. What about a race that develops spaceflight and then loses it?”

“It happens. There are lots of ways a space-going species can revert to animal. Atomic war. Or they just can’t live with the complexity. Or they breed themselves out of food, and the world famine wrecks everything. Or waste products from the new machinery ruins the ecology.”

“’Revert to animal.’ All right. What about nations? Suppose you have two nations next door, same species, but one has space flight…”

“Right. Good point, too. Morris, there are just two countries on Earth that can deal with the Monks without dealing through the United Nations. Us, and Russia. If Zimbabwe or Brazil or France tried it, they’d be publicly