Dr. Cale’s smile was warm, but my skin felt cold. Everything about me was cold, like the temperature in the room had suddenly dropped below freezing. I didn’t like the things that she was saying. I didn’t like them at all.

“I had to learn everything,” said Adam haltingly. “It took a long time. Everyone’s been very kind. Mom most of all.”

“Adam’s been awake for almost a year and a half,” said Dr. Cale. “He’s done remarkably well, don’t you think?”

The pounding was in my ears again. “I’m not like that,” I blurted. “I had an accident, and I was unconscious for a while, but I’m not like that. I’m me. I didn’t have to learn everything from scratch, I remembered things during my therapy. I remembered things all the time.” Things like reading and writing and how to put together a sentence. Things like walking and doing basic math. There were things I’d never remembered, like slang and where I went to elementary school—anything about the girl I’d been before the accident—but that was different. Those memories were in a different part of the brain.

I wasn’t like him. I wasn’t like it.

“Did you have an implant before your accident, dear?” asked Dr. Cale calmly.

“Yes,” I whispered.

“Then you can’t be like Adam. I understand why you’re concerned—I would be too, if I had your medical history—but you don’t need to be. The implants are too territorial. There’s no way yours would have tolerated the introduction of a second to its habitat.” Dr. Cale smiled at me. It was probably meant to be reassuring. It chilled me even further. “It would take a miracle for something like my Adam to happen under natural conditions. Tansy is proof of that, aren’t you, Tansy?”

“Right as rain in the middle of a drought, Doctor C,” said Tansy brightly. She rocked onto her heels, and said, “I didn’t have caring parents who kept me on the plugs until a helpful stranger offered to come along and buy me for science. I had a tag that said ‘Jane Doe’ and a deadline for someone to come and claim me before the doctors pulled the plug. Lucky for me, Doctor C came along and managed to spring me loose. Only there’d been a lot of damage, and the girl who’d been me before wasn’t home anymore, so the Doc figured I’d make a great test subject.” She glanced to Dr. Cale. “Did I get that right?”

“A little out of order, dear, but yes, you got the broad details of what happened,” said Dr. Cale. “Tansy was a ward of the state. When I heard about her case, she had just been declared legally dead and was only being kept alive to fulfill a few formalities before they began using her for organ donations. I simply chose to keep all the organs in their original conformation. I needed to test something.”

“What’s that?” asked Nathan warily. He took a step back, putting our shoulders in a line with each other. I reached over and laced my fingers into his, grateful for his presence. If I’d been trying to deal with this alone, I would have been hysterical and crying in a corner by now.

“Adam isn’t properly a member of D. symbogenesis as the species is currently recognized. He may be the only representative of his subspecies, but he’s distinct enough to be an entity in and of himself. He was able to take over a properly prepared host, one that was already ideally suited to his needs. I needed to know whether the D. symbogenesis worm introduced into the general population could do the same thing. I had no idea whether the implants being handed out like candy were capable of taking control of and integrating with a human host.”

“Can they?” asked Nathan. He still sounded like he didn’t quite believe her, maybe because he didn’t want to. I, on the other hand, believed every word.

And I didn’t want to. Because if they were all true…

“You bet we can!” Tansy beamed at him. “I am new and improved and don’t even remember most of the time that I’m actually an invertebrate in really fancy pants! I mean, when I remember pants, which isn’t always.” She flung her hands up in the air like she was waiting for applause that would never come.

“There were more complications with the newer generation of worms,” said Dr. Cale calmly, once again acting as if Tansy hadn’t spoken. That really was a time-saver. “She didn’t mesh quite as well with her host’s nervous system. Her physical coordination is good, but she demonstrates some neurological oddities that I would have preferred to avoid.”

“That means I like taking people apart, and she really wishes I’d stop doing that, because it’s antisocial and stuff,” said Tansy.

Adam frowned at her. “Taking people apart is rude.”

Tansy stuck her tongue out at him. “That’s what I just said.”

It was like watching children interact. Fully grown, adult children who were either delusional or were actually the hosts of sapient tapeworms. Given everything else that was going on around us, I didn’t know which one I wanted to believe. There was something inhuman about both of them. Something…”wrong” wasn’t the right word. Dr. Morrison would have called it a judging word if I’d brought it up during one of our therapy sessions. Then he would have made a note on his pad, and I would have found myself with another six months of appointments.

Tansy and Adam weren’t wrong. They were just somehow other; whatever they’d been before was gone. And that’s what Dr. Cale was saying happened.