“No,” said Vadesh. “It infiltrates them. It echoes the neural network. It takes over and controls the host’s behavior.”
“Why in the world would our ancestors bring along such a creature when they came from Earth?” asked Umbo.
“They didn’t,” said Olivenko.
“How do you know that?” asked Loaf. His tone showed he was still skeptical of Olivenko, who was only a member of the city guard in Aressa Sessamo, rather than a real soldier.
“Because if they had, it would exist in every wallfold,” said Olivenko, “and it doesn’t exist in ours.”
Olivenko thinks the way Father taught me, thought Rigg. Don’t assume: Think it through.
Vadesh was nodding. “A very tough little creature, the facemask.”
“Facemask?”
“What the humans of this wallfold named it. For reasons that would have become tragically obvious if you had bent over to drink from the stream.”
Something didn’t ring true about this. “How can a creature that evolved on Garden successfully take over the brains of creatures from Earth?” asked Rigg.
“I didn’t say it was successful,” said Vadesh. “And you are now as close as is safe. To avoid picking up facemasks from the wet ground beside the stream—they can attach to any skin and migrate up your body—you should follow in my footsteps exactly.”
They followed him in single file through the grass, with Rigg bringing up the rear. The path Vadesh took them on was the highest ground. Each time they reached a damp patch they jumped over it. The rill was narrow here. No one had trouble overleaping it.
Only when they got to higher ground several rods beyond the rill was Rigg able to continue the conversation. “If the parasite wasn’t successful, why is it still alive here?”
“The parasite is successful in attaching to humans and Earthborn beasts of all kinds,” said Vadesh. “But that’s not really how we measure success in a parasite. If the parasite kills its host too quickly, for instance, before the parasite can spread to new hosts, then it has failed. The goal of a parasite is like that of any other life form—to survive and reproduce.”
“So these facemasks kill too quickly?” asked Umbo, shuddering.
“Not at all,” said Vadesh. “I said ‘for instance.’” He smiled at Rigg, because they both knew he was echoing Rigg’s earlier testy reply when Vadesh told him his time estimate was off by a millennium.
“So in what way did this parasite fail?” asked Rigg—the way he would have pushed Father, an attitude that came easily to him, since not just in face and voice but in evasiveness, smugness, and assumption of authority this expendable was identical to the one that had taken Rigg as an infant from the royal house and raised him.
“I think that with native species,” said Vadesh, “the parasite rode them lightly. Cooperating with them. Perhaps even helping them survive.”
“But not with humans?”
“The only part of the earthborn brain it could control was the wild, competitive beast, bent on reproduction at any cost.”
“That sounds like soldiers on leave,” said Loaf.
“Or academics,” said Olivenko.
Vadesh said nothing.
“It sounds like chaos,” said Rigg. “You were there from the beginning, weren’t you, Vadesh? How lon
g did it take people to learn of the danger?”
“It took some time for the facemasks to emerge from their chrysalises after the disaster of the human landing,” said Vadesh. “And still longer for the people of Vadeshfold to discover that facemasks could infest humans as well as cattle and sheep.”
“The herders never got infected?” asked Loaf.
“It took time for a strain of facemasks to develop that could thrive on the human body. So at first it was like a pesky fungal infection.”
“And then it wasn’t,” said Rigg. “Facemasks are that adaptable?”
“It’s not blind adaptation,” said Vadesh. “They’re a clever, fascinating little creature, not exactly intelligent, but not completely stupid, either.”