“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-

That what? A new daddy Passenger was threatening my Passenger? I had run into many people in my life who had the shadow of something similar to mine hung over them, and nothing had ever happened with them except mutual recognition and a bit of inaudible snarling. This was too stupid even to think about-Passengers didn’t have daddies.

Did they?

“Dexter,” Astor said. “You’re scaring us.”

I admit that I was scaring me, too. The thought that the Passenger could have a parent stalking it with lethal intentions was appallingly stupid-but then, after all, where had the Passenger really come from? I was reasonably sure that it was more than a psychotic figment of my disordered brain. I was not schizophrenic-both of us were sure of that. The fact that it was now gone proved that it had an independent existence.

And this meant that the Passenger had come from somewhere. It had existed before me. It had a source, whether you called it a parent or anything else.

“Earth to Dexter,” Astor said, and I realized that I still stood in front of them frozen in my unlikely, foolish openmouthed pose like a pedantic zombie.

“Yes,” I said stupidly, “I was just thinking.”

“Did it hurt a lot?” she said.

I closed my mouth and looked at her. She was facing me with her look of ten-year-old disgust at how dumb grown-ups can be, and this time I agreed with her. I had always taken the Passenger for granted, so much so that I had never really wondered where it had come from, or how it had come to be. I had been smug, fatuously content to share space with it, simply glad to be me and not some other, emptier mortal, and now, when a little self-knowledge might have saved the day, I was struck dumb. Why had I never thought of any of these things before? And why did I have to choose now as the first time, in the presence of a sarcastic child? I had to devote some time and thought to this-but of course, this was neither the time nor the place.

“Sorry,” I said. “Let’s go see the planetarium.”

“But you were going to tell us why lions are important,” she said.

In truth, I could no longer remember why lions were important. But happily for my image, my cell phone began to chatter before I could admit it. “Just a minute,” I said, and I pulled the phone from its holster. I glanced at it and saw that it was Deborah. And after all, family is family, so I answered.

“They found the heads,” she said.

It took me a moment to figure out what she meant, but Deborah was hissing in my ear and I realized some sort of response was called for. “The heads? From the two bodies over at the university?” I said.

Deborah made an exasperated hissing noise and said, “Jesus, Dex, there aren’t that many missing heads in town.”

“Well, there’s city hall,” I said.

“Get your ass over here, Dexter. I need you.”

“But Deborah, it’s Saturday, and I’m in the middle of-”

“Now,” she said, and hung up.

I looked at Cody and Astor and pondered my quandary. If I took them home it would be at least an hour before I got back to Debs, and in addition we would lose our precious Saturday quality time together. On the other hand, even I knew that taking children to a homicide scene might be considered a little bit eccentric.

But it would also be educational. They needed to be impressed with just how thorough the police are when dead bodies turn up, and this was as good an opportunity as any. On balance, even taking into consideration that my dear sister might have a semi-ballistic reaction, I decided it would be best simply to pile into the car and take them to their first investigation.

“All right,” I said to them as I reholstered my phone. “We have to go now.”

“Where?” Cody said.

“To help my sister,” I said. “Will you remember what we learned today?”

“Yes, but this is just a museum,” Astor said. “It’s not what we want to learn.”

“Yes, it is,” I said. “And you have to trust me, and do it my way, or I’m not going to teach you.” I leaned down to where I could look them both in the eyes. “Not doodly-squat,” I said.

Astor frowned. “Dex-terrrr,” she said.

“I mean it. It has to be my way.”

Once again she and Cody locked glances. After a moment he nodded, and she turned back to me. “All right,” she said. “We promise.”

“We’ll wait,” Cody said.

“We understand,” Astor said. “When can we start the cool stuff?”

“When I say,” I said. “Anyway, right now we have to go.”

She switched immediately back to snippy ten-year-old. “Now where do we have to go?”

“I have to go to work,” I said. “So I’m taking you with me.”

“To see a body?” she asked hopefully.

I shook my head. “Just the head,” I said.

She looked at Cody and shook her head. “Mom won’t like it.”

“You can wait in the car if you want to,” I said.

“Let’s go,” said Cody, his longest speech all day.

We went.

D EBORAH WAS WAITING AT A MODEST $2 MILLION HOUSE on a private cul-de-sac in Coconut Grove. The street was sealed off from just inside the guard booth to the house itself, about halfway down on the left, and a crowd of indignant residents stood around on their carefully manicured lawns and walkways, fuming at the swarm of low-rent social undesirables from the police department who had invaded their little paradise. Deborah was in the street instructing a videographer in what to shoot and from what angles. I hurried over to join her, with Cody and Astor trailing along right behind.

“What the hell is that?” Deborah demanded, glaring from the kids to me.

“They are known as children,” I told her. “They are often a byproduct of marriage, which may be why you are unfamiliar with them.”

“Are you off your fucking nut bringing them here?” she snapped.

“You’re not supposed to say that word,” Astor told Deborah with a glare. “You owe me fifty cents for saying it.”

Deborah opened her mouth, turned bright red, and closed it again. “You gotta get them outta here,” she finally said. “They shouldn’t see this.”

“We want to see it,” Astor said.

“Hush,” I told them. “Both of you.”

“Jesus Christ, Dexter,” Deborah said.

“You told me to come right away,” I said. “I came.”

“I can’t play nursemaid to a couple of kids,” Deborah said.

“You don’t have to,” I said. “They’ll be fine.”

Deborah stared at the two of them; they stared back. Nobody blinked, and for a moment I thought my dear sister would chew off her lower lip. Then she shook herself. “Screw it,” she said. “I don’t have time for a hassle. You two wait over there.” She pointed to her car, which was parked across the street, and grabbed me by the arm. She dragged me toward the house where all the activity was humming. “Lookit,” she said, and pointed at the front of the house.