I reached out to grab a passing rung and swung inward, bouncing against the stone wall and holding on for a bare second, the breath knocked from me. Then the peep was dropping toward me, hissing, teeth bared. His body struck me broadside, wrenching my fingers from the ladder rung. We fell together, landing in a crumpled heap on the pile of pigeon feathers, his wiry muscles writhing against me.

Black fingernails raked across my face, and I scrambled free and jumped away into the tunnel, cracking my head against the low stone ceiling. Dizzy from the impact, I spun to face him, hands raised.

The peep leaped up in an explosion of feathers, his black claws lashing through the air. I held up the injector to ward him off, and felt his flailing hand connect with it, a brief hiss sounding before the injector flew away into the darkness. The peep’s next blow struck my head, knocking me to the ground.

He stood over me, silhouetted by the sunlight, swaying a little, like a drunk. I scrambled backward, crab style. He let out another scream…

Then tumbled heavily to the ground. The injection had knocked him out.

That good old peep metabolism, fast as lightning.

I blinked a few times, shaking my head, trying to force the pain away.

“Ow, ow, ow!” I said. I rubbed at a bump already rising on my scalp. “Stupid tunnel!”

When the pain had faded a little, I checked his pulse. Slow and thready, but he was alive—for a peep, anyway. The injection would keep him out for hours, but I tagged him to be certain, handcuffing him to the lowest ladder rung and sticking an electronic bracelet around his ankle. The transport squad could follow its signal here.

Finally, I sat back and grinned happily, letting a rush of pride erase my pain. Even if he was family, this was my first peep capture outside my own ex-girlfriends. I turned him over to look at his face. Thinner than his photograph, his cheekbones high and hair wild, this was a barely recognizable Joseph Moore. He looked way too skinny for a seven-month-old peep, though, considering the pile of feathers he’d accumulated.

What had he been doing at the top of the ladder, up there in the sun?

I pulled myself up the ladder, noting how smooth the walls of the shaft were. Too slick for a cat to climb, or even a rat—only a human being could make use of it.

At the top, the afternoon light slanted through the steel-grated window. The view was the Hudson River, from only a few feet above the water level. From just overhead I heard laughter and the hum of Rollerblades.

I was inside the stone bulwark at the edge of the island, I realized, right below the boardwalk where people jogged and skated every day, only a few feet from the normal daylight world.

Then I saw the broken black column in front of me, a pylon from an old pier, a rotting piece of wood just big enough for a pigeon or a seagull to perch on. There was bird crap all over it, and it was just within arm’s reach.

Joseph Moore had been hunting.

Then a realization swept over me, and I gripped the ladder rungs with white knuckles, remembering the picked-clean pigeon skeletons and feathers back in the swimming pool. Joseph Moore was too skinny to have eaten all those birds at the bottom of the shaft; most had been carried away. He had been hunting for the brood. With his long human arms, he had brought them food that they couldn’t reach.

But unlike most human peeps, Joseph Moore wasn’t at the center of the brood. He’d been stuck out here on this lonely periphery, the hated sunlight shining in to blind his eyes, forced to give up his kills for the pack to eat.

He was nothing but a servant to the brood’s real master.

“The cat has people,” I said aloud.

Chapter 14

SLIMEBALLS SAVE THE WORLD

Okay, remember those slimeballs? The ones with lancet flukes in them? It turns out that they do more than just infect cows, snails, and ants. They help save the world.

Well, okay, not the whole world. But they do make sure that the corner of the world where ants and cows and snails live doesn’t come crashing down. Here’s how it works:

When cows are looking for something to eat, they stay away from grass that’s really green. Green grass is good for them, but it’s green because of the cow pies fertilizing it. Now, these cow pies don’t cause problems in themselves—cows are smart enough not to eat them. But cow pies have lancet flukes in them. Thus, there are fluke-infected snails nearby, which means that there must be flukey ants sitting atop stalks of green grass, waiting to be eaten.

So cows have evolved to avoid bright green grass. They don’t want to get infected with lancet flukes, after all.

But a problem arises when there are too many cows and not enough grass to go around. The cows wind up eating the green grass, and getting lancet flukes in their stomachs. Less grass to go around, more sick cows. And, it turns out, sick cows have fewer calves. The cow population drops, and there’s more grass for everyone.

Get the picture? The parasites control the population. They’re part of nature’s balance.

So what happens if you get rid of the parasites? Bad things.

Not long ago, some cattle ranchers decided to increase their herds with parasite-killing medicine. They doped every cow until all the parasites were gone. So their cattle had more and more calves, and they ate all the grass, green or not. More hamburgers for everyone!

For a while.

It turned out that those little clusters of bright green, parasite-laden grass were important. They were holding down the topsoil. Without parasites to keep the cows in check, every square inch of grass got eaten, and soon the grassland turned into a desert. New plants came in, desert shrubs that made it impossible for grass to return.

All the cows died. All the snails died. Even the ants got blown away.

Without our parasites to keep us in check, we’re all in trouble.

Chapter 15

THE PATH BELOW

Joseph Moore was still unconscious, snoring softly on the feathers. Maybe dreaming of his cat master.

I wondered if Dr. Rat would try to explain this new development away as just another hopeful monster. Surely a human who served a peep cat would take a few generations to evolve. Of course, people and cats have been getting along for thousands of years, since the Egyptians worshipped them as gods. Maybe this was just a new twist on that, or on the toxoplasma thing.

Whatever was going on, I had to catch this cat. The yowl I’d heard from the swimming pool must have come from the other end of the ventilation tunnel, downwind. Which meant that it would smell me coming.

“Fine,” I whispered. I was armed with one more can of Crunchy Tuna, after all.

Facing the tunnel, I realized that my night vision was gone. Glimpsing the afternoon sun across the Hudson had left me half blind, seeing only spots and traces against the darkness. I closed my eyes to let them readjust to darkness, moving slowly back down the tunnel.

Then I heard a noise, faint footfalls in the dirt.

My eyes sprang open, but the tunnel ahead remained absolutely black. The only scents came from behind me—the pile of feathers and the sleeping peep. I swore softly no longer so proud of my hunting instincts. Just like Joseph Moore, I had been cornered, blind and upwind. And my spare knockout injector was in my duffel bag.

I crouched in a defensive stance, listening hard.

No sound at all came from the darkness. Had I imagined the footsteps?

My stuff had to be up there somewhere, probably only a few steps away. I gritted my teeth and scuttled forward, sweeping my hands back and forth across the dirt, hunting for the cold metal of the flashlight.