I know what you did.

Blake Morgan stared at the piece of paper in his hand, pulse accelerating, a tiny finger of ice slithering down his spine. Again. Someone had left it again. A message with the same words.

Goddamnit!

He looked around to see if he could spot whoever this was, the familiar fear gripping him, his stomach knotting. But he knew he'd see nothing. He never did. Whoever this was moved like a ghost, silent and unseen, leaving his taunting messages. If he wanted to keep Blake on edge, he was doing a damn good job of it. In a fit of anger, Blake crumpled the paper and stuck it in the drink holder of the car. He wasn't going to let some unknown asshole frighten him. He'd faced worse than this.

He'd found the damn stupid note stuck under his windshield wiper when he went to get his car from the hotel parking garage. Anyone could have done it. Who paid attention to cars in a parking garage, anyway? And why would they? But Jesus. How the hell had someone known which car was his? It was a rental, for crap's sake.

Wait! Were those footsteps? Was someone running toward him? Away from him? A car door slammed somewhere and an engine turned over. He looked around, wondering if he'd see someone hiding in the shadows, every nerve on high alert.

Okay, get your shit together. You aren't a character in one of your books.

Anyway, whoever was doing this wouldn't be quite so obvious. He — or she — would be careful and silent. He closed his eyes, drew in a deep breath and let it out slowly. Calm, he told himself. People were waiting for him. His readers. He couldn't freak out on them.

Crap. Double crap.

Who in the fucking hell was doing this? Who could he have pissed off so much they'd do something like this? A reader he'd offended? Reviewer? Blogger? Not anyone he'd been dating, for sure. He was so busy these days that dates weren't even on the horizon.

So really. These messages. What the fuck?

He'd blown off the first note as a prank, a harmless joke, although he didn't think it was very funny. Or maybe even a case of mistaken identity.

Just the one sentence on a plain sheet of paper, typed on someone's computer.

I know what you did.

He had no idea who it was from. There was no signature, no return address. The postmark was Boston, but he was pretty sure none of the people he knew in that city would be sending him a message like this. He had a lot of readers from that area, but he never gave out his address or phone number. And nothing had been coming in to his public email.

So how the fuck did whoever this was know where he was staying?

Maybe they'd followed him to the hotel, a thought that brought another attack of the creeping chills.

I know what you did.

His agent had made light of it. "The price of fame," Henry had joked. "It brings the weirdos out of the woodwork. This is your third best seller so you've got a lot more eyes focused on you. You've had nutty stuff like this happen before. Okay, maybe not quite like this. But eventually, when you don't make a big deal about it in the media, they give up and move on to someone else. Whoever this is will get tired of the game and disappear."

But that hadn't happened. The notes kept coming, showing up in different cities wherever he was signing. Different hotels and venues. Someone was tracking his tour. Not just the cities but also the facilities — bookstores, event centers, wherever.

The police weren't much help. They were courteous, but the events all happened in different cities, so nobody really had jurisdiction. And, as one overly polite detective told him, he didn't think this was a case for the FBI.

I know what you did.

Five words that plagued him.

In the past three weeks, the frequency increased. He found notes left everyplace for him. When he checked in at his hotels there was one waiting for him at the front desk in an envelope. No, no one could remember who left it. In a restaurant, he went to the restroom and when he came back a note sat at his place setting. And of course no one had noticed anyone leaving it. None of the notes were handwritten. They were either printed with marking pen or typed on a computer like this one had been.

Then came two emails, but when he tried to reply to them they bounced back.

Twice.

And phone calls, four of them now, at the hotels where he stayed.

"I know what you did."

Just a whisper, but unnerving in its very anonymity.

He rubbed his forehead, willing away the headache blooming just beneath the surface.

Just last week both his agent and publisher told him to toss his existing cell and get two new ones — one for business and one for personal. But then, this week, something new was added — text messages on his cell. His damn personal one. How the hell had anyone gotten that number? When he tried to reply, his message came back undeliverable.

Today was his last stop before a one-week break. He just needed to get through this afternoon and then he could regroup.

He pulled out of the garage on to the street, heading for Slater's Books, where today's signing was scheduled. He had less than an hour to get there, get set up and make sure to thank the people hosting it. The manager had called an hour earlier to let him know the store was already full and a line was forming. He really wanted to enjoy his success. Bask in it a little, after the hard climb to get to this point, one book at a time. Having some asshole tarnish it and throw him off his game really pissed him off.

He sure couldn't let all that show. He needed to get his shit together before he faced everyone.

Other authors had told him horror stories about fans who stalked them, or people who were jealous of them and tried to make trouble. He considered himself both blessed and lucky. After slogging in the trenches with his first three books, at thirty-five years old he'd finally hit the best-seller lists with number four and number five. His current release, Deep Cover, had been in the top ten for five straight weeks.

Now it seemed in his celebrity he'd acquired a stalker. Apparently someone was determined not to let him enjoy his success.

He wasn't a man easily frightened, but so many incidents in such a short time could sure make a person uneasy. If he could just figure out who the hell was doing this to him and why.

And then, of course, he had to deal with Annemarie leaving, with almost no notice. She would have known what to do about this. She knew what to do about everything. She'd been the personal assistant from heaven for four years, efficient, not rattled about anything, able to juggle multiple chores and situations and relieve him of any stress. All he had to do was write, go over research with her, and show up wherever she told him to. She'd handled his social media, kept his schedule, assisted him with his research, kept his notes organized. And on the weeks he didn't need her, he'd arranged for her to have paid time off. In all that time, they'd hardly had a disagreement.

He still hadn't figured out why she'd had to leave. And those were the exact words she'd used.

"I have to leave," was all she said. "I'm sorry, Blake. I have some personal things I really have to deal with."

He had no idea what those things were, because she never discussed her personal life with him. He'd asked her if it...