Lizard looked up from the console. "The machine put him out. He was straining."

"He hates drugs. I'm going to have a lot of apologizing to do." I realized what I'd said and looked up at her. "Sorry. Force of habit."

She didn't smile. "There's something else you want to watch out for."

"Huh?"

"You could have pulled that cartridge, you know."

I shook my head. "No, I couldn't. It's those bugs. If we're going to be eaten alive, he's better off not knowing."

Lizard looked at me sharply. "That's what I'm talking about. That kind of thinking is the first step."

"What kind of thinking?"

"Making other people's decisions for them. The next step is deciding whether or not they should continue living. And you know where that leads. I seem to remember you had a button on that."

"Yeah, well-" I stood up and climbed into the turret above Duke. "It's different when you're the person who has to do the deciding, isn't it?"

She didn't say anything immediately. She just studied me with an introspective look on her face.

Finally I glanced down at her. "Well, go ahead. Say it."

She shook her head slowly. "I don't have to. You already know what I would say."

"No, I don't."

"Yes, you do."

"God!" I said. "I hate conversations like this."

She sighed. "It's not important. I just wondered if you would have accepted that justification?"

I didn't answer. I turned away from her and pulled the shutter back. I stared at the uneasy surface of the bubble. The creatures were more active than ever in the afternoon sunlight. I could feel the sweat dripping down my sides. I didn't want to continue this conversation any more. I knew she was right.

And my chest hurt worse than ever.

IT WASN'T until late afternoon that the bugs finally cleaned off the turret bubble well enough so I could see them clearly.

The sunlight was slanting directly into the rear of the chopper and there were only pink streaks left on the clear canopy of the bubble to suggest that the ship had once been covered with the dust.

The insect-things were very tiny. Most of them were nothing more than little white specks. Few were big enough to have features. I had to strain my eyes to see them at all.

I called to Lizard, "Have you got a surveillance camera?"

"I've got a couple of electronics."

"That'll do. Let me have one, please."

She passed it up.

"Ah, good-it's a Sony. For once the army didn't buy cheap. I'll show you a trick I learned. You can dial these down for incredible closeups. We used to use them in school as portable microscopes." I braced myself and focused the camera on the insect-things on the surface of the bubble. The lighting was perfect. The afternoon sunlight was coming in sideways. The detailing on the image was perfect. The little bugs were white and powdery and-when the instant of recognition hit me, I felt my relief like a shot of Irish whiskey.

I started giggling. "What's so funny?"

I closed the shutter and dropped out of the bubble. I was laughing so hard I started coughing. I had to sit down on the floor of the chopper to catch my breath. I hadn't realized how tense and anxious I'd been. Now, it was all pouring out of me at once.

"McCarthy!" Lizard was getting annoyed. "What is it?"

"Come on up front, I'll show you." The bugs were clearly visible at the top of the windscreen. I handed her the camera. "Look-do you recognize them?"

She peered up at the windshield through the eyepiece. "No."

"You should. You saw Dr. Zymph's slides."

"Will you just tell me what they are?"

"Those are baby pipe cleaner bugs! They are absolutely harmless to human beings! These and the cotton candy are the only two Chtorran species that are not directly dangerous to us-and we've been hiding here in the chopper terrified all day! By tomorrow morning, they'll have cleaned this entire ship off. There won't be a speck of pink anywhere on this aircraft." I sat down in the copilot's seat again, feeling terrific, a big silly smile on my face. "We're going to be all right."

Lizard sat down across from me, looking relieved and relaxed for the first time today. "We're really not in any danger?"

"Not in the slightest. I feel like such a jerk."

Lizard laughed. "We should celebrate. You want a beer?"

"You got more beer?"

"That cooler by your feet."

I pulled the top open. "Jeez-you don't travel light, do you?"

She spread her hands apologetically. "You never can tell when you're going to be buried in cotton candy. Hand me one, thanks." We sat back in our seats and watched the bugs work on the windshield. We passed the camera back and forth.

Lizard said, "You're a biologist, aren't you?"

"I never got my degree."

"That wasn't the question."

"All right, yes, I'm as much a biologist as anyone is these days."

"Thanks. So, tell me-what s going on?"

"I can make a guess. The pipe cleaner bugs hatch on the same day as the puffballs explode. The puffballs are their primary food."

"But why so many? The scale of this-it's enormous."

"Uh huh," I agreed. "It's a good breeding strategy for bugs. Have zillions of offspring. That guarantees that enough will survive to breed the next generation." Another thought occurred to me then. "Of course ... that's a Terran explanation. The Chtorran explanation could be something else entirely."

"What do you mean by that?"

"Just a guess. Remember how Dr. Zymph said that what we were seeing was really the advance guard-that some extraterrestrial agency was obviously trying to Chtorra-form this planet?"

"Yeah, so?"

"Well, I've been thinking. Suppose we humans were going to Terra-form Mars or some other nearby world. Would we take our entire ecology? Probably not. No, we'd only take those creatures suited for the kind of climate and terrain we'd be moving into. In fact, we wouldn't even take the full spectrum of creatures, we'd only fill the ecological niches that we need to support our own survival. "

"What are you getting at?"

"Okay-we'd take a couple species of grass and grain, earthworms, rabbits, foxes to keep the rabbits in check, cows, ducks, chickens, and so on. That is, we'd take only those species immediately useful to us. We wouldn't bother with mosquitoes, termites, rhinoceroses, or three-toed sloths. I'll bet the Chtorrans have done the same thing. That's why the puffballs and the pipe cleaner bugs have experienced population explosions. There aren't the usual wide range of predators present to feed on them. At least not yet. Maybe they'll be here later."

"Mm," said Lizard. She took a drink from the can of beer, then leaned forward and tapped the window. "What's this?" she asked. She was pointing at a larger, darker speck.

I looked. The speck was round and black and very busy. "That's the creature that feeds on the baby pipe cleaner bugs," I said.

"Well that didn't take long," she said. "There's your first predator." She peered through the camera. "It looks like a spider-only it's got too many legs."

"If it's Chtorran, it's a mouth on wheels. Here's another. And another. It's nearly dusk-the night feeders are coming out. I'll bet we'll be seeing a lot more of them."

"And this?" pointed Lizard. "What are these?" She passed me the camera.

I looked where she pointed. The creatures looked like red-striped silverfish. They made me think of millipedes-these were the micro-size. Or maybe the larvae.... I said, "Obviously, these are the bugs that feed on the bugs that feed on the pipe cleaner bugs." I shifted my attention to a thing that looked like a fingernail-sized amoeba. Incredible. It was enveloping one of the silverfish. "You know what we've got here? Box seats! We're seeing a whole slice of Chtorran ecology."