“Oh, well,” Carl said modestly, “more or less.”

Outside the jail, the thunder crashed and the rain began. I looked at Carl with real interest; now I knew what had unsettled my Dark Passenger. We were just starting out, and here was somebody who had already been there and back, on eleven occasions, more or less. For the first time I understood how my classmates at Ponce might feel when they came face-to-face with an NFL quarterback.

“Carl enjoys killing people,” Harry said matter-of-factly. “Don’t you, Carl?”

“It keeps me busy,” Carl said happily.

“Until we caught you,” Harry said bluntly.

“Well, yes, there is that of course. Still…” he shrugged and gave Harry a very phony-looking smile, “it was fun while it lasted.”

“You got careless,” Harry said.

“Yes,” Carl said. “How could I know the police would be so very thorough?”

“How do you do it?” I blurted out.

“It’s not so hard,” Carl said.

“No, I mean-Um, like how?”

Carl looked at me searchingly, and I could almost hear a purring coming from the shadow just past his eyes. For a moment our eyes locked and the world was filled with the black sound of two predators meeting over one small, helpless prey. “Well, well,” Carl said at last. “Can it really be?” He turned to Harry just as I was beginning to squirm. “So I’m supposed to be an object lesson, is that it, Sergeant? Frighten your boy onto the straight and narrow path to godliness?”

Harry stared back, showing nothing, saying nothing.

“Well, I’m afraid I have to tell you that there is no way off this particular path, poor dear Harry. When you are on it, you are on it for life, and possibly beyond, and there is nothing you or I or the dear child here can do about it.”

“There’s one thing,” Harry said.

“Really,” Carl said, and now a slow black cloud seemed to be rising up around him, coalescing on the teeth of his smile, spreading its wings out toward Harry, and toward me. “And what might that be, pray tell?”

“Don’t get caught,” Harry said.

For a moment the black cloud froze, and then it drew back and vanished. “Oh my God,” Carl said. “How I wish I knew how to laugh.” He shook his head slowly, from side to side. “You’re serious, aren’t you? Oh my God. What a wonderful dad you are, Sergeant Harry.” And he gave us such a huge smile that it almost looked real.

Harry turned his full ice-blue gaze on me now.

“He got caught,” Harry said to me, “because he didn’t know what he was doing. And now he will go to the electric chair. Because he didn’t know what the police were doing. Because,” Harry said without raising his voice at all and without blinking, “he had no training.”

I looked at Carl, watching us through the thick bars with his too-bright dead empty eyes. Caught. I looked back at Harry. “I understand,” I said.

And I did.

That was the end of my youthful rebellion.

And now, so many years later-wonderful years, filled with slicing and dicing and not getting caught-I truly knew what a remarkable gamble Harry had taken by introducing me to Carl. I could never hope to measure up to his performance-after all, Harry did things because he had feelings and I never would-but I could follow his example and make Cody and Astor toe the line. I would gamble, just as Harry had.

They would follow or not.

T HEY FOLLOWED.

The museum was crowded with groups of curious citizens in search of knowledge-or a bathroom, apparently. Most of them were between the ages of two and ten, and there seemed to be about one adult for every seven children. They moved like a great colorful flock of parrots, swooping back and forth through the exhibits with a loud cawing sound that, in spite of the fact that it was in at least three languages, all sounded the same. The international language of children.

Cody and Astor seemed slightly intimidated by the crowd and stayed close to me. It was a pleasant contrast to the spirit of Dexterless adventure that seemed to rule them the rest of the time, and I tried to take advantage of it by steering them immediately to the piranha exhibit.

“What do they look like?” I asked them.

“Very bad,” Cody said softly, staring unblinking at the many teeth the fish displayed.

“Those are piranha,” Astor said. “They can eat a whole cow.”

“If you were swimming and you saw piranha, what would you do?” I asked them.

“Kill them,” said Cody.

“There’s too many,” Astor said. “You should run away from them, and not go anywhere near.”

“So anytime you see these wicked-looking fish you will either try to kill them or run away from them?” I said. They both nodded. “If the fish were really smart, like people, what would they do?”

“Wear a disguise,” Astor giggled.

“That’s right,” I said, and even Cody smiled. “What kind of disguise would you recommend? A wig and a beard?”

“Dex-ter,” Astor said. “They’re fish. Fish don’t wear beards.”

“Oh,” I said. “So they would still want to look like fish?”

“Of course,” she said, as if I was too stupid to understand big words.

“What kind of fish?” I said. “Great big ones? Like sharks?”

“ Normal,” Cody said. His sister looked at him for a moment, and then nodded.

“Whatever there’s lots of in the area,” she said. “Something that won’t scare away what they want to eat.”

“Uh-huh,” I said.

They both looked at the fish in silence for a moment. It was Cody who first got it. He frowned and looked at me. I smiled encouragingly. He whispered something to Astor, who looked startled. She opened her mouth to say something, and then stopped.

“Oh,” she said.

“Yes,” I said. “Oh.”

She looked at Cody, who looked up again from the piranha. Again, they didn’t say anything aloud, but there was an entire conversation. I let it run its course, until they looked up at me. “What can we learn from piranha?” I said.

“Don’t look ferocious,” Cody said.

“Look like something normal,” Astor said grudgingly. “But Dexter, fish aren’t people.”

“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-”