"Booby-trapped chromosomes?" Festina asked.
"Exactly. Here’s the scenario. Aliens land on Muta. The defense system activates. It gathers samples of the invaders’ tissues-"
"How?" I interrupted.
"Probably with squads of nanites: microscopic robots. The nanites sneak into the invaders’ bodies, grab some cells, and sneak away. They deliver the cells to a site where defense system computers do a complete analysis. It’s not a quick process — the Unity have been on Muta for what, six years? That’s how long it took the defense system to develop a bug that targets Homo unitatis. But once the defense system designed an attack agent, the bug was mass-produced and sent in swarms to every Unity camp. The germs surrounded each person and flooded everybody’s metabolism; then the germs broke open and spread their nasty little chromosomes everywhere. Once the cells in every human body were infected, the defense system sent out a signal that set the bad chromosomes off. Result: everybody goes poof."
"Pretty elaborate for a weapon system," Festina grumbled. "If you wanted to defend your planet, wouldn’t your priorities be simplicity and speed? Simplicity reduces the number of things that can go wrong. Speed means maybe you’ll still be alive after the weapon has gone off. I mean, if hostile visitors show up on your doorstep, what good is a weapon that takes six years to mount a defense? By then, truly warlike invaders might have killed all the original population."
"But the invaders wouldn’t be killers, would they?" I said. "The League of Peoples won’t let murderers travel from one star system to another. Aliens landing on Muta couldn’t be totally homicidal."
"Hmm," said Festina, "you’re right. People coming here wouldn’t be stone-cold killers. They couldn’t be. At worst, they’d be aggressive settlers… like the Europeans who came to the Americas after Columbus. Most Europeans weren’t maniacs who got a kick out of massacring natives. They were just greedy and self-centered. They wanted the riches the natives had; they usually only murdered those who got in their way. If the same thing happened on Muta…"
"If aliens showed up," I said, "the Fuentes would do their best to keep things peaceful. Maybe they’d give the invaders gifts or negotiate treaties. They’d go along with practically anything, just to avoid confrontation for a few years… and they’d get away with it because the newcomers were guaranteed to be halfway reasonable people. The League automatically eliminates anyone who’s totally ruthless."
"Right," Festina agreed. "So the Fuentes would give the newcomers whatever was necessary to keep the peace. Six years later, after the defense system has analyzed the invaders and developed attack germs… suddenly, all the invaders get vaporized simultaneously. Problem solved. And the bugs would remain in the atmosphere to wipe out any more of the same species who dropped by."
Tut nodded. "That’s Var-Lann’s theory."
Festina smiled grimly. "If he’s right, it wasn’t a bad defense strategy. Better than fighting the invaders directly — war makes such a mess. If the Fuentes acted conciliatory until their automatic defense system produced a means of genocide… lots fewer casualties and property damage. At least on the Fuentes’ side."
"Of course," I said, "the League of Peoples would consider the entire Fuentes civilization nonsentient. A sentient civilization wouldn’t callously slaughter visitors."
"Var-Lann talked about that too," Tut said. "He thought the Fuentes on Muta were a splinter group: a breakaway from mainstream Fuentes culture. They didn’t behave like other Fuentes, did they? The other Fuentes cleaned up before they transcended the flesh… but the Mutan Fuentes didn’t. Var-Lann believed the Mutan Fuentes had turned rabidly isolationist. They split from the rest of Fuentes society and built their defense system to keep other species out."
"So the Mutans didn’t meet the League’s definition of sentience," Festina said, "but it didn’t matter. The League only kills nonsentients who try to leave their home star system. The Mutans were isolationist stay-at-homes who didn’t want to leave anyway. They kept to this one planet, and the League never touched them."
I nodded to myself. It wasn’t uncommon for planetary populations to turn isolationist — especially on beautiful worlds like Muta, with all the necessities of life. Even in the Technocracy, most planets had secessionist movements. The general public usually considered such movements to be crazy… but all a movement needed was a charismatic leader plus a few unpopular decisions by the central government, and soon breaking away became a serious topic of discussion.
During my lifetime, three star systems had cut ties with the Technocracy. One had since returned to the fold, but the other two continued to turn in on themselves, becoming steadily more xenophobic. Some experts thought it was only a matter of time before those two systems began shooting outsiders who came too close.
Was that what had happened to Muta? Had the people here split from the rest of Fuentes civilization, eventually building a draconian defense system to slaughter all visitors? Had that defense system built supergerms, killing the Unity survey teams and the Greenstriders that came before them?
No, I decided. It wasn’t as simple as that. For one thing, Var-Lann and his teammates hadn’t really been killed — they’d been turned into clouds that retained purpose and intelligence. And what about the shadow chromosomes in Var-Lann’s cells? Where did that come in?
Festina was obviously having similar thoughts. "Tut, did Var-Lann say anything about dark matter?"
"Not a word," Tut answered. "At least nothing I understood. There was a part where he completely lost me — almost a full minute. Sorry."
"Can’t be helped," Festina told him. "We’re lucky you understood anything." She looked around the room as if searching for hints of what to do next. Nothing presented itself. Finally, she turned back to Tut, and asked, "Is that it? Did Var-Lann say anything else?"
Tut paused, then said, "Yeah. He, uhh… he knew we were from the Outward Fleet. He recognized your tightsuits. And even though I spoke his language, he knew I was from the Technocracy too."
"Why?" Festina asked.
"Because I wasn’t dead. Last time Var-Lann looked, there were still plenty of bugs in the air. If any of us had twenty-four Unity chromosomes, we’d be smoke by now. But…"
"But?"
"Var-Lann pointed out that Homo sapiens aren’t much different from Homo unitatis. One chromosome, that’s alclass="underline" the Unity has that one extra chromosome. And as chromosomes go, it’s pretty damned small — fewer than a hundred genes. Just a handful of things the Unity have added to themselves, and put onto a brand-new chromosome for fear of screwing up older DNA structures." Tut took a deep breath. "So if Var-Lann was right about this automatic defense system, he thought we were in big trouble."
"Because the system is already creating a defense against us," Festina said grimly.
"Right. And genetically, we’re damned near identical to the Unity. All but that one chromosome. As soon as the system starts analyzing us, it’ll see we’re almost the same… so it’ll be able to turn us to smoke with almost the same bugs. It sure as hell won’t need six whole years to produce appropriate attack germs. Var-Lann thought the system might mount an assault within days. Or hours. He told us to get off Muta fast."
"We can’t," Festina said. "The only way to leave is a Sperm-tail. If we try that, the EMP cloud will ride up the tail and zap Pistachio. We’ll still be stuck, and the ship will be stuck with us." She shook her head. "No. Whatever trouble we’re in ourselves, there’s no point endangering Pistachio too."