Parasite

retarded to guarantee that it would reach that size only after more than two years had passed, creating a ‘safety margin’ where balance could be maintained between parasite and host.”

“That’s why the two-year replacement requirement,” said Nathan. “That never made sense to me. Nature doesn’t work on such a tidy schedule.”

“Exactly. They don’t die after two years. They never did. The antiparasitic drugs take care of the old tapeworm, and a new one is put in place without anyone realizing that there was ever a risk.” Dr. Cale shook her head. “If it had ever gotten out, it would have been the end of SymboGen.”

“And a lot of people would have been hurt,” I said.

Dr. Cale seemed to wave my concerns away, continuing, “Everyone was meant to forget about the early generations, even though the final product was heavily influenced by their design. When Steven sent the word that the IPO was coming, I saw the writing on the wall. Eventually, there’d be so much money in the picture that everyone who had been there in the early stages would be in danger. We’d know too much. Well, I knew I’d need some kind of insurance if I was going to guarantee my safety—and by extension, yours, Nathan. Since I didn’t participate in the human testing, I was a suitable host.”

The Intestinal Bodyguard was fiercely territorial, and wouldn’t tolerate the presence of another worm in the body. Supposedly, this meant that a second tapeworm introduced into the body would just fail to thrive, and would eventually starve to death. According to some of the stories Nathan had told me, the first tapeworm would actually attack and devour the second. I wasn’t clear on how that happened, since tapeworms weren’t supposed to be that intelligent. I was pretty sure I didn’t want to know.

Nathan, on the other hand, did want to know. “What did you do, Mom?” he almost whispered.

“I went back into my lab and got one of the early versions of D. symbogenesis out of cold storage. And then I implanted it in myself, so that I could carry it out of the building without anyone the wiser. Most of the employees already had Intestinal Bodyguards by that point, so testing for parasites wouldn’t give me away, and I suppose Steven just assumed I knew better than to risk ingesting an early-generation worm. He didn’t count on the power of sentiment.” Dr. Cale smiled wistfully. “That was my Adam. He was my first, and greatest, creation. You know, Nathan, he had just as much of my genetic material in him as you did? He was virtually your brother.”

“I don’t know whether I should be flattered or feel sick,” said Nathan. He looked like he was leaning toward the second option. I stepped closer to him, trying to lend support through proximity. He smiled at me a little, looking strained, and didn’t say anything. There wasn’t really anything to say.

“Feel like your mother is a genius, and be glad I was willing to share my genes with you, not just with your brother,” said Dr. Cale. She sighed. “I didn’t have a choice, Nathan. Steven was going to destroy my work, and he was going to do it so that if things went wrong with the worms, he could claim there’d never been any indication of a potential risk to human health. He was going to pin it all on me, and by extension, he was going to pin it all on you. How long do you think our connection would have stayed secret after I became the person who recklessly endangered the lives of millions?”

“Still,” said Nathan. He was staring at the white mass on the X-ray like he could find the outline of the worm in the blur. “It was a big risk.”

“And I paid for it.” Dr. Cale spoke with absolute calm. “I ingested Adam and left the lab. I had to wait a month for him to grow long enough that we’d be able to extract segments without killing him. We needed to keep him alive, as proof that there had been earlier generations—that D. symbogenesis didn’t somehow spring fully developed from a test tube and a set of irresponsible testing procedures.”

“Didn’t you take your antiparasitics after that?” I asked.

Dr. Cale nodded. “I did, because I am not a complete idiot, current evidence aside. Unfortunately for me, we’d never tested Adam’s generation inside a human host, and we didn’t realize what the results would be.”

“There was too much human DNA in the early generations,” said Nathan. “The antiparasitics might have made the worm sick, but they couldn’t kill it without being increased to a level where they’d kill you, too.”

“That’s exactly right. Sadly for me, we didn’t realize that at the time. I took my pills like a good girl, and I passed enough dead tapeworm segments that I was sure we’d managed to clear Adam entirely out of my digestive system. We had our samples, and that meant that we could re-create the living worm at any time if we needed it to prove what SymboGen had been doing. You have to remember, I developed the Intestinal Bodyguard. It was more my baby than anyone else’s, no matter how much Steven may try to rewrite history. I didn’t approve of the way he was going about things, but I truly wanted to see D. symbogenesis thrive. If people could find a way to coexist peacefully with the worms, everyone would benefit.”

“SymboGen more than anyone else,” said Nathan. “What happened?”

“I’m getting there.” For the first time, Dr. Cale’s voice was sharp, holding the snap of authority she needed to organize her own underground lab and control this many people. “What happened, Nathan, is that we didn’t realize the antiparasitics hadn’t worked until I began losing feeling in my legs. It was intermittent at first, just pins and needles. Bit by bit, it turned into a numbness that didn’t go away. It could still have been sciatica, brought on by hard living and exacerbated by stress. I thought I was working too hard. I thought I was getting old. I didn’t think that the antiparasitics might have driven my stolen tapeworm out of my intestine and into my abdomen. He was very clever in what he did and didn’t chew through—instinct is a powerful thing, and he didn’t want to kill his host—but when he reached my spine, he didn’t have anywhere else to go. He was too large to migrate upward at that point, which is the only reason I’m alive today. So he compressed my spinal cord more and more tightly, until the day he permanently compromised the nerves. I collapsed in the middle of the lab.

“My assistants performed basic medical triage, including the X-ray films I’ve posted on the light box for you to study. It was immediately clear that we would need to operate. Adam and I had reached the point at which we could no longer share one body, and while I hated to do it, I couldn’t cede the ground to him. I had too much work to do. They removed eight and a half pounds of worm mass from my pelvis and abdomen. Unfortunately, the nerve damage was not so easily undone. Barring medical advances that I probably won’t live to see, I’m staying in this chair.” Dr. Cale shrugged. “I suppose I’m not the first person to see hubris as an object lesson, but I’ve worked very hard to make up for it since then.”

“Mom,” said Nathan, sadly. “Oh, Mom.”

“Don’t feel sorry for me, now. It was for science, and as long as something is for science, it’s worth doing. It’s just not necessarily worth repeating.” Dr. Cale’s smile was sudden, and very bright. “Now that we have all that out of the way, there’s someone that I very much want you to meet. You needed to understand what had happened right after I left SymboGen before this would make sense to you. All right?”

“Sure,” I said, uncertainly. “This is going to tie back into the sleeping sickness soon, isn’t it?”

“Oh, my dear Sal, the broken doors are open, and we can’t close them on our own. Believe me; everything I am telling you ties back into the sleeping sickness.” Dr. Cale looked past us, into the gloom near the back wall. “It’s all right; you can come out now, dear. They’re ready for you.”

Tansy appeared, leading a young, gangly-limbed man by the hand. He was wearing a lab coat, like everyone else we’d seen since arriving inside the bowling alley. The T-shirt he had on under the lab coat advertised a children’s TV show I’d never heard of, and his jeans were torn out at the knees. His hair was cut short, and his eyes were wide and anxious. He was probably in his twenties, but those eyes made him look like he was barely out of his teens.

“Mom?” he said, uncertainly.

“It’s all right, Adam,” said Dr. Cale, beckoning him forward. “They really want to meet you. This is Nathan, my son, and his girlfriend, Sal.”

“What’s going on here?” asked Nathan.

Tansy giggled.

I looked into the eyes of the man Dr. Cale called “Adam,” and I knew. There was no point in wasting words on asking. “He’s your tapeworm.”

Dr. Cale beamed like I’d just answered a particularly difficult riddle correctly. “Brava, Sal. There may be hope for you—and for humanity—yet.”