i probably read the message a dozen times. It didn’t become any less scary the more I became familiar with it.

There’s a funny thing about e-mail. Even though it and the rest of the Internet exist somewhere out there in the ether, when something ominous appears on your screen, addressed to you, it feels as though the writer’s there in the room with you. You’ve suffered a home invasion without the duct tape. You want to lock the door, but it’s too late. There’s no place to go.

So someone had been to visit Stefanie’s mother and learned my e-mail address. Someone who was clearly not with the police. And that was no cause for celebration.

It was time to stop kidding myself about whether Stefanie Knight’s death and the $20,000 in her purse were related. Here’s how I figured it played out: Someone had gone to her house expecting to get that money, and when she didn’t have it, she was murdered. Then her killer started looking elsewhere, and showed up on her mother’s doorstep. But she didn’t have it, either. But hey, she said, there was a guy here earlier, said he had her driver’s license, was acting kind of funny. Here’s his name and e-mail address.

I read the note one more time: “Dear Mr. Walker: I’m looking for something I think you got. Don’t do something stupid and give it to some body else.”

Hadn’t I done enough stupid things already tonight? I certainly had no interest in doing any more.

It was the absence of any specific threat that made the note all the more chilling. It was implied. I already knew what this guy would do to someone who didn’t hand over something he wanted. I’d been in that garage. But then again, he didn’t know that I knew Stefanie Knight was dead. Maybe he intended his note to be more matter-of-fact. Maybe I was reading too much into it.

Earth to Zack. Wake the fuck up.

I clicked on “Reply” and wrote: “To Whom It May Concern: Regarding your e-mail about my possessing something you’re looking for, I’m afraid I simply have no idea what you’re talking about.”

I read it over twice, thought it sounded about right. Didn’t protest too much, just stated plainly that he had made some sort of a mistake. An incorrect assumption. A case of mistaken identity, perhaps.

I hit “Send.”

My study door opened. God, did Angie want more money? How much do you need, honey? Ten thou, fifteen?

Paul said, “Are you ready?”

I looked at him blankly. “Ready for what?”

“Jesus, you forgot? We have to be there in ten minutes.”

“What are you talking about?”