Nathan lunged forward, slapping his hands against the clear plastic wall of Dr. Banks’s enclosure. Everyone jumped except for Dr. Cale. She just turned her face sadly away, her expression conveying her utter lack of surprise. She’d been expecting this.

“You bastard. How dare you,” snarled Nathan. “This is your fault. You took my mother away from me for money, and now you’re using her—”

“Kiddo, I’ve been using her since day one.” Dr. Banks sounded utterly unrepentant, and somehow that was the worst thing of all, the worst thing in a sea of terrible things. He wasn’t sorry. He might beg and plead for his freedom, and he might need us to help him, but he wasn’t sorry.

I’d been assuming Sherman and his people were the inhuman side of our conflict. They weren’t human, any more than I was. But they hadn’t started this fight, and now that it was happening, they were just trying to survive. Dr. Banks… I didn’t even know what he was hoping to accomplish anymore, aside from coming out on top of whatever world rose from the ashes of this one.

I also wasn’t entirely sure what was going on. I looked toward Dr. Cale, hoping she would explain. She met my eyes and sighed.

“He’s blaming this all on me,” she said. “I’m the one who put the human DNA in the plan for D. symbogenesis, remember? I’m the one who handed it the key to the human immune system.”

“I thought that was the toxoplasmosis,” I said.

Dr. Cale laughed. It was a brilliant, broken sound, like light glinting off a shattered window. “See, right there, you’ve shown yourself more capable of critical thinking than most of the human race. Yes, Sal, it was the toxoplasmosis that made the implants capable of migrating through the body and successfully colonizing the brain. But that’s not going to make sense to most people. They want quick, easy answers. They want sound bites.”

“ ‘Discredited geneticist inserted time bomb in essential medical supplies,’ ” said Dr. Banks, practically purring. “The Intestinal Bodyguard isn’t finished, Surrey. It can’t be. Add the world’s dependence on the drugs our implants provide to the collapse of so many supply chains, and there’s just no way to take it out of the equation. We just need to repackage it to make sure that we retain our market share.”

Dr. Cale’s head swung back around. I quailed, taking a step backward. If she had ever looked at me like that, I would have run screaming from the room. “You know, Steven,” she said, voice low and dangerous, “I’d been wondering who I should be helping in all of this. My children or the human race. I can only save one side of the equation. You’re making it much easier for me to make my choice.”

“He hasn’t answered the question,” said Adam suddenly. We all turned to look at him. He didn’t take his eyes off Dr. Banks. “He’s trying to distract us. Didn’t you notice? He’s saying everything he can to keep from actually answering the question Mom asked him. Make him answer the question.”

“Yes, Steven.” Dr. Cale looked back to her former colleague, who looked suddenly dispirited, like his last chance at getting out of this alive had been taken away from him. “Answer the question. That was the agreement, was it not? Honest answers win you limbs that work.”

“You always were a liar, Surrey,” spat Dr. Banks, his eyes fixed on her legs, just in case she missed his point. Once again, I balled my hands into fists, yearning for a free shot at his smug, terrible face. “I created my own chimera because I needed to understand how they worked. How the chemical bonds between the implant and the human host were formed, and how they could be disrupted—or encouraged to form more efficiently.”

Dr. Banks paused and sighed, shaking his head before he continued. “The chimera are perfect for certain jobs, Surrey. I’d say I was amazed that you hadn’t thought of it, but honestly, I’d be more surprised if you had. You would have to be able to step back and see the big picture. Imagine a world where the death penalty is carried out, not by lethal injection, but by termination of higher brain functions. The body would remain intact, ready to be put to work for the good of society. There are all sorts of functions that robots can’t perform yet. But a walking, thinking human body can accomplish all sorts of things.”

“You’re going to send my children to war,” said Dr. Cale.

Dr. Banks sighed again, deeper this time, like she just wasn’t getting the point. “They’re already at war. I’m just going to make it profitable.”

“Mm.” Dr. Cale’s tone was noncommittal, but her expression promised murder. “So that’s why you took my little girl. That’s why you took her apart. Because you wanted to learn how to build a better weapon. Well, Steven, your lesson has apparently been learned. What was so important that you had to bring her here? I know you like to gloat, but this is frankly irresponsible.”

“I’m here because I really do need your help.” He actually seemed to mean it this time. “I was able to transplant the worm from its original host into the body I had prepared, but I haven’t been able to fully stabilize it in its new environment. She’s not… she’s not doing well.”

“Rejection,” said Dr. Cale. She could have been smug in that moment, seeing her former coworker run up against an obstacle she had already overcome. Instead, she just sounded tired. “Did you do tissue typing before you sliced my girl open? Did you try a reaction panel, to see whether the new host’s immune system would even recognize an implant that hadn’t been tailored to it as something that could be potentially helpful? Or did you barrel full speed ahead and figure that the universe would give you whatever you wanted because you were Dr. Steven Banks, and you deserved it?”