"Like Sebastian."

She nodded. "Like Sebastian. Then you'll be a target your entire life… until someone finally gets you." She glanced at Sebastian's door. Her grip on my arm eased and I thought she might be ending the conversation; but I still had more questions.

"How do you know all this?" I asked. "About the nanites. How do you know things that scientists don't?"

"Oh, that. Forty years ago, there was a psychic man named Yoquito-came from a five-hut village near the Amazon, never learned to read or write, died young from chronic tuberculosis… but he had a hellishly powerful initiator in some analytic center of his mind, and he was undoubtedly the greatest genius ever produced by Homo sapiens. He didn't just think with his own brain; he could use all the nano around him like extra neurons. Yoquito wasn't the first person to have a power like that, but he was far and away the strongest: he claimed he could draw upon the power of every brain-nanite in the whole damned rainforest."

"So he was smart enough to figure out how psionics worked."

"He didn't just figure it out, Phil; the nanites literally explained it to him. As if they'd been waiting centuries for someone to ask, and were thrilled they could finally spill the secret. They told him about psionics and sorcery-"

"Sorcery?" I interrupted. "He knew how that worked too?"

"Sure," Myoko said. "It operates through the same nanites… just invoked a different way. Sorcerers don't have initiators in their brains; they initiate effects through gestures and invocations. If you say certain words or enact certain rituals, it triggers the nano to do specific things. Picture the nanites as trained dogs: if you say, 'Sit!' in the right tone of voice, they'll do what you want."

"Or," I murmured, thinking it over, "picture them as library functions in an OldTech computer. You invoke the correct subroutine and the nanites behave in accordance with their programming."

"All right," Myoko said, "if you insist on getting technical. The nanites respond to people performing certain actions… and those actions are intentionally bizarre so the nanites aren't triggered by accident."

"You don't think the aliens just invented crazy rituals so they could laugh at stupid humans dancing naked around a goat's head?"

Myoko nodded. "Maybe that too… but weird magical rituals date back thousands of years, well before sorcery became real. The aliens may simply have designed sorcery to match existing Earth folklore."

She was right-lots of human cultures had developed mythologies about what sorcery should look like, long before nanites made magic a reality. Those myths could easily have inspired the nanite-designers when they were deciding how sorcery would work. "What about the way the Caryatid controls fire?" I asked. "She never performs any fancy rituals."

"She must have when she was younger. When you're starting, you need exactly the right rigmarole; otherwise, you can't catch the nanites' attention. After a while, though, they begin to follow you around and pay attention to smaller and smaller signals. Like a trained dog again: at first you have to say, 'Sit!' very clearly and firmly… but once the dog gets the idea, you don't have to be so formal. Dogs even read your body language and anticipate what you want. The nanites are the same way. Think of the Caryatid's premonitions-they didn't start happening to her until that ritual with the pony and the calliope. After that, the premonitions began to trigger themselves spontaneously."

"And hauntings?" I asked. "The harp in the music room was more nanite activity?"

"Right. Rosalind had nanites in her brain, just like everybody else. Under certain conditions, especially traumatic death, the brain nanites imprint some portion of the dying person's personality on nearby nanites in the air. It's not an accident-the aliens who set this whole thing up wanted to create ghosts, in accordance with human ghost stories. If Rosalind suffered enough emotional turmoil when she died, her nanites were almost certain to create a ghostly manifestation. The ghost isn't the real Rosalind, of course. It's just an artificial reproduction of some part of the girl's psyche: deliberately manufactured for melodramatic effect."

I chewed on that a moment. What I'd seen in the music room had definitely been melodramatic-choreographed for heavy emotional impact. The soft weeping, the harp playing in an empty room, the blood… in a way, it was almost too faithful to the clichés of ghost stories. A real ghost (if there was such a thing) would probably be more original. Still… "These nanites are good at playing out scenes," I said. "Very smart."

Myoko shrugged. "What can I say? There are trillions of the little fuckers everywhere. And they were constructed by aliens who knew a lot more science than the OldTechs ever did. The nanites are smart and very powerful."

"Is there any limit to their power?"

"They're only present here on Earth, so you can't use them to travel off-planet. Apart from that, they seem to up for anything humans can imagine. Transmutation of lead into gold… teleportation… time travel…"

I gulped. "Time travel?"

"Think about it," Myoko said. "How can the Caryatid get accurate premonitions if the nanites don't play fast and loose with time? Information travels from the future back to us in the present. And Yoquito said the nanites could make physical objects do the same thing. I don't know of cases on record… but then, the records would have changed, wouldn't they?"

Ouch. Time travel always gives respectable physicists the screamie-weamies. Not that we're totally convinced it's impossible… but we know enough about the universe to realize just how much of the natural order time travel would screw up. The cliché of killing your grandfather isn't nearly as serious as killing the second law of thermodynamics. "I don't suppose," I said, "your analytic genius Yoquito ever mentioned how to avoid time paradoxes?"

Myoko shook her head. "Yoquito didn't live long enough. When the nanites explained all this stuff, he decided he had to tell someone… and the nanites directed him to a school that housed people with powers just like his. My old alma mater: the school for psychics. It took Yoquito years to make his way out of the jungle and reach the school. After that, he told what he knew, and died from his tuberculosis within a month. One of those cases where a man with a terminal illness keeps himself alive by sheer willpower until he accomplishes what he wants to do. Then he just lets go."

A short silence. After a while I had to ask, "If your school has known this for forty years, why haven't they told anyone else? Scientists would kill for this kind of information."

"That's the problem," Myoko said. "Some scientists would kill for it. At least we're afraid they might. In case you haven't noticed, we psychics don't trust outsiders. The school where I trained has no incentive to divulge the truth, and every reason to play things close to the vest. If scientists understood how psionics worked, maybe they could use that against us somehow. We didn't want to take that risk. Anyway," she said, her voice suddenly brisk, "scientists will find out soon enough. Every psychic who goes through the school is taught what's really happening; when that many people know something, it doesn't stay secret for long. I'm surprised it's lasted forty years."

"As you say, psychics don't confide in other people." I looked up and met her eyes. "Which makes me wonder why you're telling me."

She dropped her gaze quickly. "Because Sebastian is missing. Because he might be in trouble and I want to save him. You're a smart man, Phil, and who knows, maybe if you understand the truth you can use it to help."

"I'll try," I told her. "What did you say the boy's powers were?"