Whatever it was, the thing had given Kira something to concentrate on. She cross-referenced the image with the others in the database, searching for any sign of its purpose or function. Two possibilities immediately suggested themselves, and she jotted them down on her notepad: first, that Samm’s body could, at one time, produce the Blob, and that somehow that ability had been removed or reduced, leaving only this inert, nonviral structure. It was a vestigial particle, like the human appendix: the evidence of a previous function. Kira thought about that, staring at her notepad. Is this how the Partials spread RM? Did they just breathe it out and kill everyone? But then how did that function go away—what flipped the switch and made the deadly virus turn inert? The Partials are engineered, she thought. A switch like that, and the power to flip it on and off, could have been built right into them. But who holds the key to flipping it?

Kira shuddered, the ramifications twisting her stomach into queasy knots. And yet her second guess about the particle seemed even worse: that the particle in Samm’s breath was a precursor to the active virus, designed to transform on contact with human blood and become the deadly Blob. Was that the secret of Partial immunity? A virus that couldn’t even arm itself until it found a human target? That was the worst possible situation for Kira, because it meant there might be nothing she could use—no defensive mechanism she could copy from the Partials to help fight off the virus. If RM targeted humans, specifically and directly, then the only defense against it was to not be human anymore.

Maybe the only way to survive was to be a Partial.

Kira shook her head, throwing down her notepad and shoving the thought from her mind. She couldn’t think like this—she wouldn’t think like this. There had to be something in the Partial genetic code that rendered RM inert, and there had to be a way to copy it and apply it to the human genetic code. And she was going to find it. The only thing this proved for certain was that what Samm had said yesterday was true: The Partials did have a connection to RM, at a very basic level. But what was it?

She tapped on the screen, opening the particle’s profile information to give it a name. The blood-borne form was the Blob, because it was fat; the airborne was the Spore, because it was, presumably, how the virus spread. This new one she labeled the Lurker, because it didn’t have any obvious function at all. It simply sat and waited, presumably, for the right time to strike.

“You’re not going to find what you’re looking for.”

Kira started again; Samm had a funny sense of timing. But she was curious. “And how do you know what I’m looking for?”