"That's exactly right," I said. "Because people survive by recognizing things that look dangerous. And fish get caught. We don't want to." They looked at me solemnly, then back at the fish. "So what else have we learned today?" I asked after a moment.

"Don't get caught," Astor said. I sighed. At least it was a start, but there was much work yet to do. "Come on," I said. "Let's see some of the other exhibits."

I was not really very familiar with the museum, perhaps because until recently I'd had no children to drag in there. So I was definitely improvising, looking for things that might get them started toward thinking and learning the right things. The piranha had been a stroke of luck, I admit-they had simply popped into view and my giant brain had supplied the correct lesson. Finding the next piece of happy coincidence was not as easy, and it was half an hour of trudging grimly through the murderous crowd of kids and their vicious parents before we came to the lion exhibit.

Once again, the ferocious appearance and reputation proved irresistible to Cody and Astor, and they came to a halt in front of the exhibit. It was a stuffed lion, of course, what I think they call a diorama, but it held their attention. The male lion stood proudly over the body of a gazelle, mouth wide and fangs gleaming. Beside him were two females and a cub. There was a two-page explanation that went with the exhibit, and about halfway down the second page I found what I needed.

"Well now," I said brightly. "Aren't we glad we're not lions?"
"No," said Cody.
"It says here," I said, "that when a male lion takes over a lion family-"
"It's called a pride, Dexter," Astor said. "It was in Lion King."
"All right," I said. "When a new daddy lion takes over a pride, he kills all the cubs."
"That's horrible," Astor said.

I smiled to show her my sharp teeth. "No, it's perfectly natural," I said. "To protect his own and make sure that it's his cubs that rule the roost. Lots of predators do that."

"What does that have to do with us?" Astor said. "You're not going to kill us when you marry Mom, are you?" "Of course not," I said. "You are my cubs now."
"Then so what?" she said.

I opened my mouth to explain to her and then felt all the air rush out of me. My mouth hung open but I couldn't speak, because my brain was whirling with a thought so far-fetched that I didn't even bother to deny it. Lots of predators do that, I heard myself say. To protect his own, I had said.

Whatever made me a predator, its home was in the Dark Passenger. And now something had scared away the Passenger. Was it possible that, that