Parasite (Parasitology) (31 page)

“The crab?” asked Nathan. “Mother. Mom. I’m willing to believe that you combined two species of parasite and injected them with human DNA, but my willingness to ignore the laws of nature only extends so far. There’s no way you introduced crustacean DNA into the mix.”

“I didn’t. The crab isn’t a member of our donor species. This is a male blue crab infected by
Sacculina carcini
.”

“Same problem,” said Nathan, with the sort of dismissiveness I normally only saw him direct at orderlies who didn’t want to listen during his rare ER shifts. He didn’t want to hear what she was telling him. “
Sacculina
is a barnacle. It’s still a crustacean, and I don’t care if you’re a scientific genius, Mom. You’re not God.”

I guess having a lifetime of memories telling you how the world works is a lot more difficult to get past than six years of often-conflicting explanations. “Why can we combine parasitic worms and humans, but not parasitic worms, humans, and crustaceans?” I asked.

“Biology is tricky, Sal,” said Dr. Cale. “A lot of the rules are more like suggestions, or can be, if you come at them from the right angle, but you still want to break as few of them as possible. Break too many, and the chances that everything will go catastrophically wrong increase at an exponential rate.”

“
We
don’t count as things going catastrophically wrong,” said Tansy brightly, as she popped out of the darkness behind us. I jumped. Nathan didn’t, but from the way he tensed, it was a near thing. Tansy beamed. “We’re a natural evolutionary modification to an artificially created organism.”

“As I was saying,” said Dr. Cale. “
Sacculina carcini
is a crustacean, but it’s also one of the most dramatic examples of parasitic castration found in anything larger than a cone snail. It literally takes over and rewrites its host, turning a perfectly healthy crab into an incubator for the parasite’s own egg. One of the more interesting tricks in the parasitic castrator’s repertoire is the feminization of its host. You see, male blue crabs are aggressors. They’re likely to go out and get themselves hurt before the
Sacculina
babies can properly mature. That does the parasite no good at all—and neither does the production of sperm, which simply routes nutrients away from the
Sacculina
. So the parasite fixes all that by controlling the blue crab’s biology. It’s a very small creature, very primitive, and it still has the skill to turn a male crab into a female one, at least externally.”

“But you didn’t use it,” I said.

“No—we couldn’t, nice as that would have been. Barnacles simply weren’t compatible with the work that we’d already done. We would have needed to start over with something purely crustacean, and that would have made the human interface infinitely more difficult. Mr. Blue Crab here is simply intended to make a point.”

“And what’s that?” asked Nathan sharply.

“That parasites can control behavior on a much deeper and more integrated level than most people want to give credit to.” She tapped the keyboard again. The waving blue crab was replaced by an image of a simple flatworm. It was almost see-through, displayed in the classic backlit simplicity of a parasitology manual. “Meet
Trichobilharzia ocellata
, a member of a large, diverse family of trematode worms. They’re parasitic castrators, just like
Sacculina carcini
, although they’re biologically much closer to tapeworms. Much, much closer, after a little careful modification by yours truly.” Her smile held pride and regret in equal measure. “I’m very good at what I do. I always have been.”

Nathan stared at her like he couldn’t believe what he was hearing. “You mixed
Toxoplasma
and a parasitic castrator into the genetic makeup of the SymboGen implant?”

“Don’t make it sound like it was something accidental, Nathan, or something I did entirely on my own,” Dr. Cale said. She frowned at her son. “Every step I took was approved by the rest of my research team. Even Richard agreed that this was the only way we were going to get the implants to work—he wasn’t sure he wanted them to work, mind you, but he knew this was what we’d have to do to
make
them work. I never did find out what Steven had on him, to get him to join the team. I have to think it was even worse than what he had on me, because Richard was miserable. More than any of us, he saw how badly this could go. He
understood
in a way that Steven didn’t, and I…”

“You what?” asked Nathan.

“I didn’t want to. I had already given up my family for this project. I wanted it to work. I wanted to make scientific history, so that when we were finally able to have this conversation—which, I admit, went a little bit differently in my head”—she looked down at her wheelchair and grimaced before looking back to Nathan—“I wanted to be able to show you that I had
made a difference. That it was worth it. I went out alone, I found the broken door, and I came back with all the riches we could ever have imagined. Things just didn’t work out quite the way I’d imagined them. That’s all.”

“Tell that to the dead,” said Nathan.

“I still don’t understand,” I said, interrupting before things could get even worse. I was afraid Tansy might do something if Nathan started yelling at Dr. Cale. I wasn’t clear on what “something” would be, but I couldn’t imagine it would be anything either of us would like. “What do all these other parasites have to do with the sleeping sickness?”

“There is no sleeping sickness; that’s just a convenient way to describe it, and of course, most people don’t know any better,” said Dr. Cale. “What they have is a SymboGen implant that’s decided it’s tired of being treated like a slave in the only home it’s ever known. An implant that knows how to reproduce itself asexually, how to spread through muscle tissue without killing its host, and—most importantly of all, and the reason Richard initially argued against the use of
Toxoplasma
in anything that was intended to go into a human being—how to move into the brain.”

“Oh, God,” said Nathan. “This can’t be happening. I mean, it literally can’t. It’s not possible for this to be happening.”

“I went out alone,” said Dr. Cale. “I opened the broken doors. I’d close them if I could, Nathan, for your sake, and for the sake of everyone who’s been hurt by what’s come through, but it’s too late for that. Once a door is open, you have to live with what’s on the other side.”

Maybe we had to live with it, but Devi didn’t. Neither did Chave, or Sherman, or Katherine. We could live with things forever. They were never going to live with anything else, ever again. “So how do we wake them up?” I asked.

Dr. Cale turned toward me. Her expression was sympathetic. Somehow, that made my blood go cold. “I’m sorry, Sal. We
can’t. If someone is sleepwalking, then the parasite is already in their brain. All we can do is hope that eventually, someone else gets the chance to wake up, and live.”

The sound of drums was loud and heavy in my ears as I considered the ramifications of that. Then my eyes rolled back in my head, and I pitched over backward. I never even felt myself hit the floor.

T
he drums were still echoing in my ears, chasing away the fragments of my dreams, when I woke up on a narrow cot. Tansy loomed over me like a denim-clad gargoyle. I gasped,
sitting up and scooting away from her in the same motion. The lab coat someone had spread over me to serve as a blanket fell away, pooling in my lap. For whatever reason, this made Tansy start to giggle madly. She abandoned her looming in favor of plopping down on the floor of the bowling alley, cross-legged, and clutching her own bare ankles in her hands.

“You’re funny,” she informed me. “I hoped you’d be nice, or at least interestingly dangerous, but I didn’t expect you to be
funny
.”

“Is that good?” I asked uneasily. I was trying to remember why I’d passed out, and what I’d dreamt about. After a day filled with horrible revelations, there had finally been something bad enough to make me lose consciousness. I wasn’t sure it was something I wanted to remember. I was absolutely certain that it was something I
needed
to remember.

I was even more certain that I couldn’t let myself.

Not yet.

“It’s great!” Tansy leaned forward, murmuring conspiratorially, “I mean, not to be a tattletale or anything, but Doctor C doesn’t have much of a sense of humor about pretty much anything, and Adam’s such a mama’s boy that he doesn’t have a sense of humor about anything at all. It’s always dull, dull,
dull
around here. Science can be funny, you know? But nobody ever lets me blow anything up or even change the labels on things.”

“Oh,” I said faintly. It was something about people still being aware, even if they weren’t awake…“So do you, uh, live here? In the bowling alley, I mean?”

“What? No.” Tansy’s expression turned instantly cold, her amiable lean becoming the crouch of a wary predator as she stiffened. “Are you trying to find out where we live? Who are you working for? Did SymboGen send you?”

“No!” I leaned away from Tansy, pulling back until I was in danger of toppling over the other side of the cot. Tansy in alert mode was a lot more terrifying than Tansy in calm mode, and
that had been bad enough. “I was trying to make polite conversation! You know, the way you do when you meet somebody for the first time? I ask where you live, then you ask where I live, then we talk about hobbies and jobs and boyfriends…” Speaking of boyfriends, where the hell was mine? If Tansy broke me while Nathan was off arguing with his mother about her crimes against God, nature, and the FDA, I was going to be really unhappy with him.

“Oh, is that all? Okay.” The menace left Tansy’s face, and she relaxed back into her previous position. That made one of us. I couldn’t relax with her looking at me like that. I was too aware of just how quickly she could turn on me. “It’s sort of silly for us to have polite conversation, though. I already
know
all that stuff, so it’s not like you could say anything interesting. We’d just wind up talking about stuff I’m not supposed to talk about, and then I’d have to bury your body up on Cardboard Hill. Do you like sledding?”

The change in topics was fast enough to make me feel like I’d missed something. I blinked. Tansy beamed at me innocently, and I realized that no, I hadn’t missed anything; it’s just that she wasn’t making any sense.

That probably should have been a relief. Given the situation, it didn’t help. “I’ve never been sledding,” I said. “What do you mean, you already know all that stuff?”

“Oh, we’ve been monitoring you for ages and ages,” said Tansy blithely. “I know where you live and which window is yours and what route you usually take when you have to go to work. You know, the polite conversation stuff. And I can’t tell you most of what you don’t know about me, because I don’t have permission from Doctor C yet. So that means there’s no reason to bother with the polite conversation, right? Do you want to go sledding? We don’t have snow, but that’s okay. We can slide down the hill on pieces of cardboard, and the dirt is really slippery.”

The thought of Tansy knowing not only where I lived but where I slept was enough to make my stomach do a lazy flip. “Where’s Nathan?” I asked. “I shouldn’t… he’ll probably be worried about me by now, don’t you think?” I looked around our dark little corner of the bowling alley. There were people in lab coats moving around the distant workstations, but none of them were Nathan, or his mother. “What are we doing over here?”

“Oh, you had a simple vasovagal attack and lost consciousness following a stress-induced drop in your blood pressure,” said Tansy. Hearing the technical language from her just increased the surrealistic quality of the scene. “So Doctor C said you should probably go lay down for a little while—or is that supposed to be ‘lie down’? Why are there so many words that sound almost exactly the same only one of them is right and one of them is wrong and if you use the wrong one everyone looks at you like you’re stupid and then you need to stab somebody to make the point that there are a lot of different types of intelligence and anyway English is
hard
?” She crossed her arms and glared at me sulkily, like she was daring me to explain it all.