How could this have happened? What did it mean?

I saw Betsey's small body sprawled on the hardwood floor and I went cold. My hand flew to my face, a reflex over which I had no control.

The killer had stripped off her nightclothes. I didn't see them anywhere in the bedroom. The lower body was coated with blood. He'd used a knife. He'd punished Betsey with it. I desperately wanted to cover her, but I knew I couldn't.

Betsey's brown eyes were staring up at me, but they saw nothing. I remembered kissing those eyes, and that sweet face. I remembered her laugh, high-pitched and musical. I stood there for a long time, mourning Betsey, missing her terribly. I wanted to turn away, but I didn't. I just couldn't leave her like this.

As I stood in the bedroom, trying to figure out something coherent about Betsey's murder, the cell phone in my jacket pocket went off. I jumped. I grabbed it, but then hesitated. I didn't want to answer.

'Alex Cross,' I finally spoke into the receiver.

I heard a machine-filtered voice and it cut right through me. I shuddered against my will.

'I know who this is and I even know where you are. At poor, dear, butchered Betsey's. Do you feel a little bit like a puppet on a string, Detective? You should' said the Mastermind,'because that's what you are. You're my favorite puppet, in fact.'

'Why did you kill her?'I asked the monster on the other end of the phone line. 'You didn't have to do this.'

He laughed a mechanical laugh and the hairs on the back of my neck stood up.'You ought to be able to figure that out, no? You're the famous Detective Alex Cross. You have all those big, important cases notched on your belt. You caught Gary Soneji, Casanova. You solved Jack and Jill. Christ, you're impressive.'

I spoke in a low voice. 'Why don't you come after me right now? How about tonight? As you say, you know where I am.'

The Mastermind laughed again, quietly, almost under his breath. 'How about I kill your grandmother and your three kids tonight? I know where they are, too. You left your partner with them, didn't you?You think he can stop me? John Sampson doesn't have a chance against me.'