Chapter 1

SEPTEMBER 2027

Dr. Cale’s lab might have been concealed in an abandoned bowling alley, but she’d clearly never seen that as a reason for her equipment to be anything less than state-of-the-art. The MRI scanner was kept in a private room, and was as elaborate and complex as anything they had at SymboGen. I tried to focus on how surprising it was to see a piece of machinery that complicated in a place like this as I shed my clothing on the floor and allowed Nathan to help me into the scanning bed. I’d been through this process before. It made it easy for me to lie still and close my eyes, pretending that none of the last few weeks had happened; that everything was still normal, that I was still me, and not the thing that I was desperately afraid I was becoming. Or worse, the thing I was even more afraid I had been all along.

The MRI came to life around me, the hammers and clangs of the vast machine blending with the insistent pounding of the drums in my ears until there was nothing else: just sound, vibrating through my flesh, anchoring itself beneath my sternum. My flesh, my sternum. Ownership was so easy to claim, but did I have any right to it?

Please, please, it’s something else, I thought, lying to myself one last time while the option was still open to me. Please, it’s not what I think it is. Please, there’s another answer…

The MRI gave one final pulse as it shut off. The sudden silence was deafening, only slightly lessened by the hum of the automated scanning bed sliding back out into the room, where the chill air raised goose bumps on my arms and legs. I grabbed a lab coat off the side of the machine, pulling it on as I climbed back to my feet. It didn’t do much to cut the chill, but I didn’t want to spend the time to pick up my clothes.

Nathan was seated at the monitor, the display reflecting off his glasses as he pulled up the first images of my insides. I stopped behind him, putting my hand on his shoulder. He put one of his hands over mine, using the other to continue working the mouse.

My abdomen should have been occupied by a lot of things: organs, scarring, and the pasty white mass of the SymboGen implant, which would naturally gravitate toward the base of my digestive system. It wasn’t there. The blood tests had been telling the truth: there was no residual tapeworm protein in my blood because there was no tapeworm in my digestive system. Nathan clicked to the next image. It wasn’t in my lungs, either. The image after that proved that my spinal cord was clean.

His fingers tightened on mine. I think that if I had told him to stop then, he would have, and we would both have walked away with the question unanswered. I didn’t tell him to stop. I needed to know. He did too, if only so that we would both be standing in the same place for once.

Nathan clicked the mouse. Everything changed.

The image showed the inside of a human skull, normal save for some small remodeling of the bone toward the back. The brain was there, lit up in bright colors that represented activity during the MRI. The tapeworm was there too, showing up as loops of nonreactive white against the bright neural map. It was deeply integrated, slithering in and out of brain tissue. But I’d known that before I’d seen the image, hadn’t I? I’d figured it out when I met Adam and Tansy, when I was faced with the reality of their existence. When I’d started to care about them, despite their monstrous origins.

Even knowing what they were hadn’t been strictly necessary, had it? Sherman was a tapeworm too, and I had always liked him best, out of all the people at SymboGen. From the moment I’d met him, I’d liked him. If I’d had even the slightest clue that he was a product of Dr. Cale’s lab, that would have given me the information I needed. When I met a tapeworm, when I met somebody like me, I liked them. I couldn’t help myself. Even if I’d wind up disliking them later, I started from a place of “you are family.”

So yes, I’d figured it out, and then I’d locked it away, because I hadn’t wanted to admit it to myself. Admitting it would make it real. Only I guess pictures could do the same thing, because I didn’t even try to deny that the image on the screen was me.

For the first time in my life, I was looking at who—at what—I really was.

I was never Sally Mitchell after all.

“The protein markers couldn’t cross the blood-brain barrier in a detectable form,” said Nathan. His voice was soft, like he was afraid anything louder would startle me. He wasn’t wrong. “It’s why we couldn’t detect…” He stopped, obviously unsure how to finish the sentence.

There was no kind way to do it. “Honey, you’re not human” isn’t a conversation either of us was equipped to have. “Mom was right,” I whispered. She’d called me a stranger, and it had hurt, but it hadn’t hurt as much as it should have, had it? No, because I’d already figured out the same thing she had: that I wasn’t Sally. Her daughter died in the accident that put her in the hospital. I was a stranger living inside her baby’s skin. I was a stranger to the entire human race. “Oh, my God. Nathan. Do you see…?”

“It doesn’t change anything,” he said, suddenly fierce. He let go of my hand as he stood, pushing the chair out of the way before he turned and wrapped his arms around me. He pulled me against him, holding me so tight that I was almost scared he would crush me. I put my arms around him in turn, doing my best to hug him just as hard. Voice still sharp, he said, “Do you understand me? It doesn’t change anything.”

I raised my head and looked over his shoulder. Dr. Cale had parked her wheelchair in the doorway. She was sitting there watching us, an expression of profound regret on her face. I wouldn’t have believed that she was capable of looking so sad, but in that moment, she managed it, and in that moment, she looked like her son. Coloring and race didn’t matter, not when stacked up against that expression.