“What happened to your eyes?” I asked, before I could think better of the question.

“I like that better than ‘hello,’ ” said Tansy. “That’s how we should just all greet each other from now on.” She stepped into the apartment, glancing shamelessly around.

“What if nothing’s happened to the eyes of the person you’re talking to?” asked Nathan, closing the door behind her.

“That’s easy, silly.” She smiled, showing far too many teeth. “That’s when you do something to their eyes.”

“Um,” I said.

“Please don’t,” Nathan said.

“Spoilsports.” Tansy sighed extravagantly. “Colored contacts. One blue, one brown is really noticeable, but brown and brown isn’t, so much. So this is me, being incognito. You know what ‘incognito’ means, right? Is there any fruit punch? I like the Hawaiian kind.”

“I don’t think ‘incognito’ has anything to do with fruit punch,” I said dubiously.

“Ah, no, there isn’t any,” said Nathan. “We weren’t expecting you. Is everything all right?”

“Oh, no,” said Tansy. “World of no. All the no. The Tropics of Negative. Situation is not good, not peachy, and not keen.”

“I’m going to go out on a limb and guess ‘no,’ here,” I said. “What’s going on?”

“Lots of things,” said Tansy. She cocked her head. “Which one did you want to know about in specific?”

I stared at her. Nathan came to my rescue, saying, “Whichever one was important enough that you’ve shown up here.”

“Oh. Well, why didn’t you just say so?” Tansy rolled her matching eyes. “Amateurs. Okay, so here’s the skinny: Doctor C sent me to let you know that now that Sal’s not at her house anymore, SymboGen’s probably going to move on her and try to take her into protective custody, like, soon, since the sleepwalkers are becoming more of a problem. Oh, and we cut a few of them up? I mean, it sucked to do it, since it wasn’t their fault and they’re technically like, cousins of ours and everything, but we needed to know what was in their heads, and that meant that we had to kill a few of them for the sake of science.” She looked pleadingly at me, like she was waiting for reassurance.

Feeling awkward, I gave her what she was looking for: “Sometimes we have to do things for science that we wouldn’t have done normally.” Also, I didn’t understand why SymboGen would want me in “protective custody,” but that didn’t feel like a Tansy question. That felt like a Dr. Cale question. One that was best asked in person.

“Yeah, exactly, just like that. Anyway, when we cut their heads up? Their brains were pretty much intact.” Tansy stopped, looking between the two of us like she expected an epiphany to shake us both, leaving us understanding her completely.

The epiphany didn’t come. “Isn’t reduced brain damage a good thing?” asked Nathan.

“Oh, totally—I wish I had reduced brain damage, or at least, I wish bananas didn’t taste like tangerines all the damn time—but this isn’t the good kind of reduced brain damage. This is the kind of reduced brain damage where the cousins are doing less damage burrowing into the brains of their hosts, which means a quicker adjustment and integration period, and maybe even some of them managing to take over without anybody noticing.”

Nathan blanched. “Ah. No, that’s not the good kind of reduced brain damage.”

“See, that’s exactly what I was saying! Well. Without the stuff about the bananas, but hey.” Tansy shook her head. “We’ve known for a while that this was possible without surgical intervention. You’d need just the right set of circumstances, and up until now, we thought you also needed just the right genetic template for the cousins. Only these are newer cousins—some of them haven’t been in their hosts for more than six months—and they’re managing to slide right in there, lickety-split. And that’s bad. They’re not seamless yet, but they’re gonna be, if we don’t figure out what’s changed on the genetic level.”

“As fascinating and horrifying as all this is, why are you here?” Nathan frowned. “Mom could have explained what you’d found when Sal and I managed to sneak away next. It shouldn’t be more than a few days.”

“She’s here because the implants are teaching each other, and that means that as more of them figure out how to get into the brain without killing or permanently damaging their hosts, they’re going to go on to teach even more,” I said. I barely recognized my own voice. “You only need a few pioneers. That means we need to know how they’re doing it, and we need to know sooner, rather than later.”

“Exactly,” said Tansy, beaming like I’d just done something exceptionally clever. I didn’t feel clever. I felt small and scared, and not even the distant pounding of the drums was helping me hold on to the scene in front of me. “That’s why we need you to go to SymboGen as soon as you possibly can.”

“We can’t just walk into SymboGen,” said Nathan. “They’d know something was up.”

“I’m sorry, was I unclear?” Tansy beamed at him. “I don’t mean ‘we.’ I don’t mean you, and I don’t mean me. Just her.” She pointed at me. “Sal’s going to go in alone, and she’s going to find out what they know and we don’t.”