Nathan walked grimly toward the sleeping man’s bedside. “He’s been asleep for the past twenty-four hours,” he said. “He was still moving up until then, but now he seems to have gone into the next stage of the disease, whatever that means. There’s no response to stimuli of any type. His family wants to disconnect life support; the hospital is paying all medical costs from this point on, for the sake of being allowed to keep working with him.”

“But… why?” I asked. “If his family’s ready to let him go…” I felt like a hypocrite even as the words left my mouth. My family had been ready to let go. If I hadn’t regained consciousness when I did, I would have died.

Nathan glanced back toward me, grimacing a little as he saw my discomfort. “This isn’t like what happened with you, Sal. You had an accident. We knew what caused your coma, and no matter how much research we did, we were never going to find a cure for car crashes. This is different. This is something infectious, and we need to find a way to stop the spread.”

A new discomfort curled in my stomach. “Should we be wearing masks or something if we’re going to be in here?”

“No. Whatever causes this isn’t airborne. We’ve run every test we could think of, and there’s nothing.” Nathan bent forward, folding back the blanket that covered Beverly’s owner. “It’s baffling our best people. It’s baffling me.”

“Why are you involved? Shouldn’t this be an infectious disease case?”

“I’m involved because everyone in the hospital is involved. No one gets to sit out an epidemic.” Nathan produced a pair of blue plastic gloves from his lab coat pocket, pulling them on over his hands. I was relieved to realize that he wouldn’t be touching the sleeping man’s skin. “How far above your skin did she hold the light?”

“About an inch and a half,” I said. “She was especially careful with the undersides of my arms and the insides of my thighs.”

“All right,” said Nathan. He clicked on the wand. It buzzed slightly, lighting up with the same purplish glow as Dr. Lo’s wand. Then he lifted the man’s left arm. It came without resistance, utterly limp, and remained limp as Nathan ran the wand along it. Like Dr. Lo, he checked the outside first, and then switched to examining the inside of the man’s arm, where it would have been closest to his body.

Just between the elbow and armpit, Nathan stopped. “Sal,” he said, a sick fascination in his voice. “Come and have a look at this.”

I didn’t want to have a look at anything. I went anyway. It’s always better to understand than it is to be left sitting in the dark; it’s always better to have answers, even when those answers lead to fresh questions.

This answer definitely led to fresh questions. The light from Nathan’s wand made most of the skin beneath it glow a pale purple, unremarkable because it was so consistent. But at the middle of the light, in the center of the man’s arm, was a system of what looked almost like roots that glowed a bright, painful white instead of matching the purple around them. I stared.

The roots moved.

It was just a twitch, barely movement at all, but it was enough to startle us both. I let out a small shriek, dancing backward, away from the man in the bed. Nathan dropped his arm, taking a long, somewhat more dignified step away from him.

“What is that?” I demanded.

“It’s a parasitic infection—I don’t know what type. Whatever it is, it fluoresces under ultraviolet light,” said Nathan. He sounded astonished and sickened at the same time, like he’d been suspicious, but had never wanted to have his suspicions confirmed. “These people don’t have a disease. They have a parasite, and it’s taking them over.” He turned to look at me, eyes wide. “Why is SymboGen hiding this?”

“I have a better question,” I said. “What happens when they find out we know?”

Naturally, there were concerns about the Intestinal Bodyguard™ when we started human trials. Shanti was worried about the worms. She was always very maternally inclined toward them, and she wasn’t sure they’d been tested enough to be placed in human hosts. Richard, he was on the other extreme. He was worried about our human volunteers, and whether the Intestinal Bodyguard™ might somehow damage their immune systems permanently when it was only trying to help. I was the moderating influence on both of them. That was my job most of the time when we were together. Shanti built castles in the air, Richard talked about how they were going to collapse, and I built foundations underneath them.

We didn’t need to worry, as it turned out. Human and implant fit together like they’d been designed for one another. In a very real way, they had been.

—FROM “KING OF THE WORMS,” AN INTERVIEW WITH DR. STEVEN BANKS, CO-FOUNDER OF SYMBOGEN. ORIGINALLY PUBLISHED IN ROLLING STONE, FEBRUARY 2027.

You know what’s funny? In the official literature, Steve tries to claim that D. symbogenesis was my idea, and that I somehow managed to sell everyone else on the idea that this was a line of research worth pursuing. If you check the actual publications, however, you’ll see that my timeline matches up a little better with reality: I was brought into the project six years into the development cycle. I had to work fast and dirty to make up the ground that had already been frittered away on dead ends and useless research channels.

I made D. symbogenesis. I have no qualms about admitting that. It is my baby. But I’m not the one responsible for cutting out most of the potential quality-control time. That award is reserved solely for Dr. Steven Banks. I’ll take the credit—and the blame—for what I actually did. I won’t take the rest of it, and he can’t make me.