Many thanks to all the usual suspects for their support and patience: my husband; my mother-in-law, Sandy, the guerrilla bookmark distributor; my family in California, who forbore to slap me silly when I deserved it; my fabulous agents, Steve and Joshua, and all their associates; the stellar team at Penguin/Roc—Anne, Ginjer, Cherilyn, Sarah, and the talented production team too numerous to list; the lovely lunatics at Bouchercon, RAM, and Crimespree; friends and family in person and those online; all the wonderful writers who've helped me along the way and put up with my whinging about this book; and the readers who pestered me to "write faster!” And a shout-out to the Seattle bookstore folks who let me run rampant through their shops in this novel.

Special thanks to: Richard Kaufman of the Genii Forums for help with table-tapping techniques; Detective Nathan Janes for information about SPD criminal and homicide investigations (I fudged a bit here and there to make things more dramatic); and to the friends who let me borrow their names for characters in this book (Ken George, Ana Choi, Rey and Karen Sous)—any resemblance to their real selves or lives is strictly imaginary.

If I've forgotten someone—and I'm sure I've forgotten many some-ones—I hope they will forgive me my Swiss-cheese memory. I'm indebted for everyone's assistance, and where I've gotten things wrong, it's entirely my own fault.

Living, lambent fog overlay the living room around me. Vague shapes and eddies moved through the gleaming mist trailing subtle colors while the bright gold of the houses protective spell coiled around the structure like a friendly vine. It was almost restful in that place and company, though I doubted I'd ever come to like it. Though Mara Danziger was safely in the normal world while I was in the Grey, I was able to see the sleeping child in her lap as a white shape, and my friend had been shrouded in a blur of blue light and gold sparks. I was even able to hear her, though the sound had a slight underwater quality to it.

"You know, you don't go slipping accidentally anymore," Mara said in her tumbling Irish voice. "That's good. Are you still seeing things the same way?”

"Yes, and no," I murmured, sitting on the couch—the shadowy shape of a couch on my side—and closing my eyes. "When I'm in here, it's not much different. When I'm outside, I can look at it without having to go all the way into the Grey, but I see layers now, and colors—people and things have. . colors, like threads, tangles, glows. I can slide down below the fog if I want to and look at the power lines—”

"Can you, indeed?”

"Yeah. The deep part of the Grey is like. . It's all bright lines, like computer drawings." Then I shut up because I didn't want to say that the lines weren't just lines or conduits or paths; they were somehow alive and I felt compelled to conceal that.

Mara was quiet a moment. "I think that's the grid itself—the network I've told you of, through which raw magic flows.”

"What are the colors? What do they mean?" I asked.

"I'm sorry to say you'll know more than I on that score. I don't see magic as you do. The glows are auras, but the others… I'd guess they're connections, like electric cords that connect related things in the Grey to each other or plug the things into the power grid, but I'm not sure. Y'could ask Ben, if he can stay awake long enough. Between the class schedules and keeping after the child, we've neither of us enough free time to spit.”

The Danzigers were both instructors at the University of Washington—Mara taught geology and Ben languages and linguistics—but they each had personal interests in the paranormal and they'd helped me out with this Grey business from the very beginning. Ben was the theoretician and scholar. Mara, being a witch, was a bit more practical.

Mara continued. "Still, you're doing much, much better than a few months ago. Feeling better about it?”

I drew a deep breath, pushing the Grey away, and opened my eyes as I exhaled. "I don't feel sick all the time," I replied. "And I don't have to live in it, most of the time. Sometimes it still gets the better of me and I fall in, but mostly I have control of it more than it has of me.”

Mara grinned at me from her couch, her green eyes sparkling, and said, "Don't go getting too cocky, now, Harper. There's still a vast trickiness to the Grey.”

I snorted. That was not news to me, even then.

That was a couple of months ago. We'd been sitting on the matching couches in the Danzigers' living room, a sunny, comfortable spot and a far cry from the slippery mist-world of the Grey—the here/not here place that lies like a fringe of shadow between the normal and the paranormal. It's the world of ghosts, vampires, and magic, and I am one of its few dual citizens. There are people like Mara—witches and so on—who can touch the Grey in some way and draw power or information from it, but as far as I know, only ghosts and monsters truly live there. I, however, seem to be half in and half out all the time. I can't do magic, or exorcise spirits, or anything flashy like that: I'm a Greywalker—a human who can enter the Grey and move through it as if it were the normal world. Apparently I got this way when I died for a couple of minutes.

So far, no one had been able to explain why me and not everyone else medical technology pulls back from clinical death, but I seemed to be the only Greywalker around the Pacific Northwest. There didn't appear to be a cure or even a way to quit, but Mara and Ben had been teaching me how to keep it under control and how to stay out of trouble, insofar as I could stay out of trouble. My work and the Grey seemed to intersect more often than I'd have liked and it hadn't been pleasant. As a private investigator, I usually carried a pretty dull caseload, but once the ghosts and vampires found me, things got weird fast.

In October, months after the calm on the couch, I wished that the meeting I was driving to would be normal, even boring, but since I'd been recommended by Ben, the self-proclaimed "ghost guy," I wasn't holding out a lot of hope. Within a few minutes of my arrival, even that bit of hope was totally dashed.

I sat in a boxlike office for twenty-three minutes as Professor Gartner Tuckman told me that he and a motley group of strangers had made a ghost. Not in the film noir, bang-bang sense but in the creepy, woo-woo sense. Frankly, I found Tuckman creepier than some of the ghosts I've met. He was thin and intense with a hectoring, arrogant manner, a sharp voice, and the cultivated piercing gaze of a silent film villain. He was also a liar—at least by omission.

I held up a finger to stem the battering wash of his words. "Let me see if I understand this, Dr. Tuckman. You put together a group of people who made up a ghost and haunted themselves?”

"No. They did not 'haunt' anything. There is no ghost. It's an artificial entity powered by their own belief and expectation. The parapsychologists would call it a group thought-form—" "I thought you were a parapsychologist.”

He scoffed. "I'm a psychologist. I study the minds of people, not spooks. The point of this project is observing how rational individuals become irrational in groups and how that is reinforced by the group itself. In re-creating the Philip experiments, I gave them an acceptable focus for their irrationality.”