"Exactly," Tut said. "The mystery bacteria contain hundreds of copies of each Unity chromosome. To Var-Lann, the germs looked like cells invaded by viruses and filled to bursting with viral copies… only in this case, the Fuentes cells were filled with human chromosomes."
"This does not sound good," Festina muttered. "This sounds very, very bad."
"Var-Lann thought so too," Tut replied. "He hypothesized the bugs were delivery systems for Trojan horse chromosomes. You know what I mean? These bugs would get inside human bodies, then break open and spill their chromosomes all over everywhere. The chromosomes would burrow into surrounding cells and… who knows? The new chromosomes would look like ones your cells already had. They’d be treated like members of the family. Next thing you know, the infiltrator chromosomes are screwing up the works somehow — making poisons, disrupting your metabolism… or turning you into smoke."
Festina made a face. "Don’t tell me Var-Lann actually considered that possibility."
"Not till he saw it happen. Until Team Esteem vaporized, Var-Lann didn’t know what the hell these chromosomes would do if they got inside a person’s cells. That sort of thing takes months to figure out."
Tut looked down at the scorch marks on the floor. "He didn’t have months, did he?"
"Okay," Festina said, "let’s go back a step. The night before things went bad, Var-Lann found Fuentes bacteria full of human chromosomes. But the flakes of skin we found — Var-Lann’s skin — had human cells full of dark matter chromosomes… or if Youn Suu prefers, chromosome-shaped holes in reality."
She waited for me to comment. I didn’t. "Anyway," Festina went on, "what the hell is going on? This shit doesn’t happen by accident."
"Of course not," Tut answered. "Var-Lann had a theory about what was going on."
"Oh good. I’d be thrilled if anyone could make sense of this."
"Don’t speak too soon," Tut said. "You won’t be thrilled if Var-Lann is right. See, he believed the mystery bacteria were created by a Fuentes defense system. A weapon intended to attack invaders who dropped in uninvited. It’s not a fast weapon, but it’s thorough. Basically, the defense weapon analyzes invaders and creates biological agents tailored to their physiology."
"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?