THIRTY-EIGHT: LENNY

 

We were floating down the third ventricle, close enough to Zooey’s hippocampus that I could actually feel the increased heat from what I guessed had to be the dentate gyrus, when I realized that something was wrong. Astro must have sensed it too, because we both stopped moving at the same time.

“You hear that?” I whispered.

“What?” He cocked his head and listened. “I don’t hear anything.”

“Exactly.” From deep inside the limbic system, the soft, continuous whir of neurogenesis, the sound of new neurons being formed—the reassuring white noise that I’d been aware of from the moment we’d passed through the blood-brain barrier—had fallen utterly silent. It was like standing in middle of a factory that had suddenly stopped production. “It’s too quiet.”

“What’s going on?” Astro asked.

“I have no idea, but...”

“Is it, like, really hot in here?”

“Definitely.”

“So where is everybody?” He stared at me, waiting. “Where are all the neurons?”

“I’m not sure,” I said, not liking the way it sounded. Ever since we’d crossed over the hypothalamus, this whole process had been way too easy. It was like something else had arrived here first and started shutting down electrical activity in the brain, circumventing Zooey’s defense systems and taking down the alarms before we’d even tripped them. And now this sudden rush of heat, with the temperature spiking higher than anything I’d felt in the rest of Zooey’s body, left me with an increasing feeling of unease, as if I were trapped inside an elevator that had just shuddered to a halt and could—at any second—decide to go plummeting downward.

“Uh, dude?” Astro said. “You might want to take a look at this.”

“What?”

“See for yourself.” He was staring down at the river of cerebrospinal fluid that had carried us this far up the third ventricle. But the CSF wasn’t clear and colorless like before. Instead, it had begun to turn thick and yellow, with streaks and threads of brownish red running through in its lower depths. It looked like a badly polluted stream outside some ruined industrial city.

“What is that?”

I stared down, unable to speak or move. There was something solid floating in the CSF as it rolled past us. After a second I realized what it was—the corpse of a white blood cell, floating belly-up with its eyes wide open and its mouth gaping like a mackerel’s. I heard Astro make a shocked noise, not quite a gasp or a grunt, but something in between, and he cast an anxious glance around to look farther up the ventricle.

“Oh, man,” Astro said. “Did you see that?”

I saw. Immediately upriver, the CSF stream was absolutely littered with dead leukocytes and neurons. Their corpses filled the ventricle with a sickish sweet smell, like the bottom of a pile of rotting leaves.

“What could do that?” I asked. “A virus?”

“Uh-uh.” Astro shook his head. “No virus that I’ve ever seen. Zooey’s up on all her shots, and believe me, I checked. What about that fungus you were talking about?”

“No, that was just a code word. And anyway, it wouldn’t look like this.”

“So...what is it then?”

“Do I look like a neurologist to you?”

“I dunno,” Astro said. “What’s a urologist?”

“Forget it.” I watched the flotilla of dead nerve cells and white blood cells clogging the CSF flow. “This almost looks more like a meningeal inflammation, or some kind of...”

“What?”

“Bacteria.”

“No way.” Astro was peering down into the infected CSF, trying to get a closer look at it. “Those bugs downstairs couldn’t get up if they wanted to.”

“Unless they came through when we did,” I said. “But how would they get in to start with?”

“I don’t know,” Astro said, bending down so close that his membrane was almost touching the CSF, “but from the look of this stuff, I think it’s—”

That was as far as he got before something reached up from out of the fluid and yanked him in.