She took a deep breath. “Here goes. Once the victim has been bit, the infecting spore has access to the bloodstream and through the bloodstream the lymphatic system. From there it hits the immune system and pretty much takes over. It can now tell the host what it’s allowed to fight off infection-wise, and programs the immune system to think that the parasite is a friend. So, once the immune system is under the control of the parasite, it’s free to roam without it getting harmed or having the host get sick.

“It next travels through the human body, using the bloodstream and lymph system, to every organ and tissue type. At each new stop, it sets up a satellite colony that adapts and mimics the organ, and it makes sure to take over shop and do any necessary repairs. This is the initial colonization—setting up satellite colonies in every organ and making sure the organ is running smoothly, and also setting up a repair shop, so to speak.” She gave Marcus a meaningful look. “Which is why you didn’t die of rabies.”

He gave a short nod.

Sofia’s attention came back to me. “And is why you most likely don’t still have the chicken pox virus in you, or even if you do, you don’t have to worry about it coming back to haunt you in the form of shingles.”

She was right. I wasn’t ready to hear this. “In other words, this zombie parasite is all through me?” I asked, swallowing hard.

“Yes. Even the brain. I’m still not sure of the exact mechanism by which it crosses the blood-brain barrier—it might simply force its way in, since it has control of everything else. But the good news is that it doesn’t kill anything.” She gave me what was probably meant to be a reassuring look. “What it does is head for the hunger center and gets itself hardwired in.” She shrugged. “And there are probably all sorts of specialized cell-cell junctions, so no way is it getting ripped out of there. Even under the worst circumstances, it’s wedged into the brain tight. And now that the satellite colony in the brain is set up, the infection is complete.”

She leaned up against the edge of the love seat and crossed her arms over her chest. “There’s more, I’m sure. Communication among the colonies, and how it manages to mimic host tissue so extraordinarily well. I mean, you have to really really be looking to see something’s amiss.”

Okay, so it looked like I was stuck being a zombie. “What about the brains? Why does it make us crave brains?”

“Prions!” she said with a proud smile. “And this is the basis of what I’ve been working on for the past several years. Prions are indestructible—they’re basically immortal proteins. Your parasitic zombie colony uses the prion proteins as building blocks and for fuel. The best part is, every time the host eats brains, the parasite has a brand new fuel supply. And, since it has its own personal hardwire into the host’s brain, it can tell it to go and get more brains whenever it’s running low on prions. If the host can’t find any immediately, the parasite takes a couple of actions. The first is, it reinforces its presence in the brain and probably takes resources from elsewhere. Now, as the colony starves and has to start shutting down sections, the first systems to go are the host maintenance—hence the decay and dropping bits and pieces. After all, it’s not altruistic.”

“Of course not,” I said weakly.

“Since the prion building blocks it uses are indestructible, the colony is fine at first, but the host tissue degrades, except for the brain—which the parasite still needs to function so it can make the decaying body try to get more brains…until it eventually runs out of steam and the host and parasite die.”

I was silent for a couple of minutes after she finished. I didn’t understand all of what she’d said, but I got the basic gist: I couldn’t be cured, and there was something in human brains that this parasite needed. “And you make fake brains?” I finally asked.

A mild grimace passed over her face. “I’m trying to make a substitute, but it’s proving difficult to isolate exactly what the parasite utilizes.”

“But she’s close,” Marcus said. “And when she gets there, it’s going to change everything for those of us with the zombie parasite.”

I opened my mouth to say that I could see a lot of problems as well, but then closed it. Marcus obviously adored his uncle, and probably wouldn’t take too kindly to me pointing out that Pietro was unlikely to simply give these artificial brains away. Plus, if it suddenly became easy to feed zombies, why not make everyone a zombie? That was a weird and rather horrifying thought. The parasite seemed relatively harmless as long as it was fed, but how did we know it wasn’t controlling us in some other way that we couldn’t sense?

“Sounds cool,” I said instead. “But now that I’ve had the biology lesson of a lifetime, can you explain how the hell Zeke—whose head was chopped off, by the way—showed up at y’all’s lab and looking about twenty years older than he did before?”

Fear returned to Sofia’s face. “I don’t know,” she said as she sank to sit on the love seat.

“Then maybe you can tell me about these ‘zombie factions’ that you mentioned earlier,” I said, looking back and forth between the two of them.

Marcus scowled. “There are other zombies out there who don’t agree with the way Pietro wants us to stay organized. Sofia’s research isn’t complete, but it still represents years of work. If the others get their hands on it, they could conceivably find another neurobiologist to finish it, and then basically corner the market and control the distribution.”

“Well, are you going to try to tell me that your uncle won’t control the distribution?” I said in thinly veiled exasperation. Sofia looked abruptly stricken. Anger flashed across Marcus’s face, but I bulled on. “Tell me the truth—do you think he intends to give these fake brains away—to everyone? Even the ones who aren’t in his ‘circle’?” I made air quotes with my fingers.

A muscle in his jaw twitched. “No, of course not, but he wouldn’t be exorbitant about it. He’s invested a lot of money in this, you know. And he’s not going to take advantage of the others of our kind.”

“Yeah, okay,” I said. “But you’re convinced that any other group of zombies would?”

His scowl deepened. “It’s certainly possible. I believe that Pietro is best positioned to organize an effective and fair distribution.”

Your uncle is a goddamn mobster, I wanted to shriek, but I kept it in. Marcus was clearly in no mood to see any other point of view. Just how deeply did his loyalties to his uncle run? How far would he go to make Pietro happy? And why? Was it simply gratitude for saving his life?

“Okay, that’s cool,” I said as lightly as I could, adding a smile to go along with it. His expression cleared somewhat, which told me that he was apparently buying my abrupt capitulation. He’s underestimating me, I realized with a strange sadness.

“Anyway,” I continued, “the guy was dressed as a security guard.” I shifted my attention to Sofia. “If he really was working for some other zombie faction,” and good grief but I felt stupid saying that, “how could he have known about your research?”

She swallowed nervously, flicked a glance to Marcus. “That’s a damn good question,” he said, his mouth curving downward into a dark scowl. “Hardly anyone knows that Sofia’s working on this, which means that there’s a leak or mole somewhere.”

“Erm, okay,” I said. Did he know how ridiculous this all sounded? Then again, the simple fact that we’re zombies is pretty damn ridiculous, I reminded myself. Why not have some sort of spy vs. spy intrigue between the various zombie mafias? “This stuff sounds so interesting,” I said, trying another tack. “I’d love to come see how this all works with you making fake brains.”

She looked briefly panicked and shook her head in a sharp motion. “No, that’s really not possible,” she insisted. “So many of the areas are strictly controlled that it’s not as if I can bring someone in, even for a tour. And I’m not about to make any sort of waves that could draw attention to myself. The lab director, Dr. Charish, has already been wondering why I’ve been pulling so many late nights.” She visibly gulped. “I’m not supposed to be working on fake brains for zombies, for reasons I’m sure you can understand. If anyone ever took a hard look at what I was doing, I could get in a lot of trouble for misuse of resources, even if they didn’t know exactly what the goal of my research was.”

I frowned, pondering. “What if Zeke wasn’t after your research? What if someone else there is doing something similar? Don’t you think it would be worthwhile to look around and see if that’s the case?”

“Don’t even think about it, Angel,” Marcus said, a warning tone in his voice.

“What?”

“Sneaking in,” he said, giving me a dark glower. “If you were to get caught trespassing it would violate your probation.”

Shit. He knew the right buttons to push on me. Going back to jail would suck enough as a regular human, but going in as a zombie would suck a lot harder—especially for anyone in my vicinity when I got really hungry.

“I won’t sneak in,” I promised.

“Besides,” Sofia said, “the security has been tightened up considerably.” She frowned and bit her lip. “But Angel has a good point. It’s possible that this whole thing had nothing to do with my projects. Under normal circumstances I couldn’t imagine that anyone would believe my lab was a target for industrial espionage, but there are plenty of other projects going on that would be worth a great deal of money to any of our competitors.” She rubbed at her eyes. “I would love to believe that this man was after the work on lipid supplementation or some such thing.”

“And you’re sure no one else at this lab is doing any sort of zombie research?” I asked her.