Like most people who own their own businesses, I work long hours that start early in the morning. So when someone calls me in the middle of the night, they'd better be dying.

"Hello, Mercy," said Stefan's amiable voice in my ear. "I wonder if you could do me a favor."

Stefan had done his dying a long time ago, so I saw no reason to be nice. "I answered the phone at"-I peered blearily at the red numbers on my bedside clock-" three o'clock in the morning."

Okay, that's not exactly what I said. I may have added a few of those words a mechanic picks up to use at recalcitrant bolts and alternators that land on her toes.

"I suppose you could go for a second favor," I continued, "but I'd prefer you hang up and call me back at a more civilized hour."

He laughed. Maybe he thought I was trying to be funny. "I have a job to do, and I believe your particular talents would be a great asset in assuring the success of the venture."

Old creatures, at least in my experience, like to be a little vague when they're asking you to do something. I'm a businesswoman, and I believe in getting to the specifics as quickly as possible.

"At three in the morning you need a mechanic?"

"I'm a vampire, Mercedes," he said gently. "Three in the morning is still prime time. But I don't need a mechanic, I need you. You owe me a favor."

He was right, darn him. He'd helped me when the local Alpha werewolf's daughter was kidnapped. He had warned me that he'd be collecting in return.

I yawned and sat up, giving up all hope of going back to sleep. "All right. What am I doing for you?"

"I'm supposed to be delivering a message to a vampire who is here without my mistress's permission," he said, getting to the point. "I need a witness he won't notice."

He hung up without getting an answer, or even telling me when he was coming to pick me up. It would serve him right if I just went back to sleep.

Muttering to myself, I threw on clothing: jeans, yesterday's T-shirt complete with mustard stain, and two socks with only one hole between them. Once I was more or less dressed, I shuffled off to the kitchen and poured myself a glass of cranberry juice.

It was a full moon, and my roommate, the werewolf, was out running with the local pack, so I didn't have to explain to him why I was going out with Stefan. Which was just as well.

Samuel wasn't a bad roommate as such things go, but he had a tendency to get possessive and dictatorial. Not that I let him get away with it, but arguing with werewolves requires a certain subtlety I was lacking at-I checked my wristwatch-3:15 in the morning.

For all that I was raised by them, I'm not a werewolf, not a were — anything. I'm not a servant of the moon's phases, and in the coyote shape that is my second form, I look like any other canis latrans: I have the buckshot scars on my backside to prove it.

Werewolves cannot be mistaken for wolves: weres are much bigger than their non-preternatural counterparts-and a lot scarier.

What I am is a walker, though I'm sure there once was another name for it-an Indian name lost when the Europeans devoured the New World. Maybe my father could have told me what it was if he hadn't died in a car wreck before he knew my mother was pregnant. So all I know is what the werewolves could tell me, which wasn't much.

The «walker» comes from the Skinwalkers of the Southwest Indian tribes, but I have less in common with a Skin-walker, at least from what I've read, than I do with the werewolves. I don't do magic, I don't need a coyote skin to change shape-and I'm not evil.

I sipped my juice and looked out of the kitchen window. I couldn't see the moon herself, just her silver light that touched the nighttime landscape. Thoughts of evil seemed somehow appropriate while I waited for the vampire to come for me. If nothing else, it would keep me from falling asleep: fear has that effect on me. I'm afraid of evil.

In our modern world, even the word seems… old fashioned. When it comes out of hiding briefly in a Charles Manson or a Jeffrey Dahmer, we try to explain it away with drug abuse, an unhappy childhood, or mental illness.

Americans in particular are oddly innocent in their faith that science holds explanations for everything. When the werewolves finally admitted what they were to the public several months ago, the scientists immediately started looking for a virus or bacteria that could cause the Change-magic being something their laboratories and computers can't explain. Last I'd heard Johns Hopkins had a whole team devoted to the issue. Doubtless they'd find something, too, but I'm betting they'll never be able to explain how a 180-pound man turns into a 250-pound werewolf. Science doesn't allow for magic any more than it allows for evil.

The devout belief that the world is explainable is both a terrible vulnerability and a stout shield. Evil prefers it when people don't believe. Vampires, as a not-random example, seldom go out and kill people in the street. When they go hunting, they find someone who won't be missed and bring them home where they are tended and kept comfortable-like a cow in a feedlot.

Under the rule of science, there are no witch burnings allowed, no water trials or public lynchings. In return, the average law-abiding, solid, citizen has little to worry about from the things that go bump in the night. Sometimes I wish I were an average citizen.

Average citizens don't get visited by vampires.

Nor do they worry about a pack of werewolves-at least not quite the same way as I was.

Coming out in public was a bold step for the werewolves; one that could easily backfire. Staring out at the moonlit night, I fretted about what would happen if people began to be afraid again. Werewolves aren't evil, but they aren't exactly the peaceful, law-abiding heroes that they're trying to represent themselves as either.

Someone tapped on my front door.

Vampires are evil. I knew that-but Stefan was more than just a vampire. Sometimes 1 was pretty sure he was my friend. So I wasn't really afraid until I opened the door and saw what waited on my porch.

The vampire's dark hair was slicked back, leaving his skin very pale in the moon's light. Dressed in black from head to heels, he ought to have looked like a refugee from a bad Dracula movie, but somehow the whole outfit, from black leather duster to silk gloves, looked more authentic on Stefan than his usual bright-colored T-shirt and grubby jeans. As if he'd removed a costume, rather than put one on.

He looked like someone who could kill as easily as I could change a tire, with as little thought or remorse.

Then his mobile brows climbed his forehead-and he was suddenly the same vampire who'd painted his old VW bus to look like Scooby's Mystery Machine.

"You don't look happy to see me," he said with a quick grin that didn't show his fangs. In the dark, his eyes looked more black than brown-but then so did mine.

"Come in." I backed away from the door so he could; then, because he'd scared me I added snappishly, "If you want welcoming, try stopping by at a decent hour."

He hesitated on the threshold, smiled at me, and said, "By your invitation." Then he stepped inside my house.

"That threshold thing really works?" I asked.

His smile widened again, this time I saw a glint of white. "Not after you've invited me in."

He walked past me and into the living room and then turned like a model on a runway. The folds of his duster spread out with his turn in an effect nearly cape-like.