She said, "Always."

She's been awake for an hour, watching out the window, when he knocks on her door. It's not quite dawn, but she's not surprised; she knows he's been awake, too.

"There's another wolf," he says.

In the small room, in the welcome dark, he seems impossibly far away.

She stands up. "I know."

He flushes, goes white. "You haven't-have you been outside? You can't go out there, Velia. It will kill you."

There is a stab in her side, just for a moment, as if he's cut her. She fights to stay calm. There is no safety with him any more.

"I'll be fine," she says.

He takes two steps. They're close enough to kiss. "Velia," he says, his voice rumbling in his chest, "that wolf snapped another's jaw clean off. What is it going to do with you?"

"Talk," she says.

To a dire wolf, the human form is like a paved street; the wolf lives in the tree roots that silently push until the stone swells and cracks and falls apart.

Velia has done better at keeping human than most wolves, but it's hard to ignore another of your kind when it comes calling.

She parks her car close to the trees. (It's a useless human habit; the wolf can run faster than any speeding car can save you.) When she's far into the forest and can smell she's alone, she folds her shirt and pants and boots under the branches of a fir tree, where the snow has not reached.

(Any dire wolf who lives in human form has had to explain their nakedness. The smart ones learn to leave their clothes where they can be retrieved before people find them naked and start asking questions.) She proceeds barefoot, wrapped in her coat-waxed cotton, the closest texture she can find to human skin. It's nice to have a human skin that doesn't hurt.

She stops short when she smells the other wolf.

The change surges into her throat like vomit; she swallows and tries to breathe. She won't give in to the wolf unless she has to.

(The pain is worse than the fight.) She reaches the clearing where the wolf has been-the smell of blood is still strong-and hangs back, waiting.

It's rare for dire wolves of the same form to fight one another. As humans they attract each other, as wolves they form packs. But those who stay in human form often go mad, or fall in love with humans, and the true wolf has no patience for either one. The human wolf must be careful.

It won't be the first time Velia's had to fight for this body.

Her father died of some human cancer. He wouldn't let anyone treat him for it ("What if they find out somehow?"), and as he took his last breaths, a ripple of the wolf's face slid over his features, a last toothsome grin before he was gone. It was how Velia would have wanted to remember him.

Her mother died later that year during a new moon, while her body was trying to make the shift back from the wolf. Velia gathered her mother in her arms and sobbed into the soft gray fur until the form in her arms was human, and Velia could pick her up and carry her home.

(The dire wolf takes human form when it dies; that lets them pa.s.s through the world without leaving proof behind.) It was her mother's broken heart that did it, Velia knew. Her mother could have lived another fifty years, another hundred-their kind was hardy, if they could strike some balance between human and wolf that didn't drive them to the brink. It was a weak heart that had taken her mother.

Velia learned early that it was safer to be alone.

She never told Mark how rare it was for a dire wolf to care for a real human. Even after he knew what she was, how could she explain what even the dire wolves struggled to come to terms with?

She told him, early, "I can't."

Later she told him, "We can't."

Just that word frightened her, the idea that there was danger to more than just herself, that she had to worry for them both.

He fought her on it. They parted badly.

But she was right. Two years after she left him, she had to identify the teeth marks on a human man who had been torn to pieces by a wild beast. A pack of coyotes, she said. The bites looked big because there had been so many of them overlapping, she said.

She never found out if the wolf had killed its own lover, or if it had been punishing another wolf for keeping human company.

Velia spent every new moon that year looking forward to the change. On four legs, at least, she could hunt without thinking.

An hour later, the wolf appears.

Velia tenses, once, just to make sure she hasn't frozen. But her muscles are warm and ready (she's never really been cold), and she's not frightened.

The wolf has never frightened her. It's how she can live as a human without losing her mind; she accepts the shape of the beast.

(In her bones, she knows that sooner or later, she'll give in to the wolf and disappear.) It pads to the edge of the clearing opposite her and stands in the shadows, waiting. Once, it shifts, and the sun catches its head for a moment-one amber eye, sharp tight muzzle-fur the color of dust.

"I'm here," Velia says. "What do you want?"

When there's no answer, she tries again, in her true language. Silence.

"Why did you kill one of your own?"

It's one of their own-the jaw of one of their own is sitting in the d.i.n.ky office lab ten miles away-but those who live as wolves don't like hearing solidarity from those on two legs.

The wolf-change claws at Velia's throat; she bites her lips against it until she tastes blood.

"What do you want?" she calls again, finally, but the wolf startles and runs, leaves nothing behind but a maze of prints and a cloud of breath that hangs in the air for a few moments after the wolf has disappeared.

She shivers; pretends it's from the cold.

Velia takes her time putting her clothes back on.

They make her feel more human, a little less afraid.

The wolf, in all things, protects itself.

It's why Velia studied animals. It's why she examines bones and tags them wolf or coyote or some breed long dead. It helps keep them all from being found out.

She fears for her kind. They are fragmented (the human-living and the beasts, taking turns hating one another more), and she knows that even under threat they would not unify. Some humans would submit to the knife rather than give in to the beast, and the true wolf would kill all comers until it died of exhaustion.

So she keeps her human shape, walks through the world, tags her jaws "Canis lupus arctos"; because what else could humans do but wipe them out, if they knew?

Velia and Mark were at the end of the Alaska winter when the thaw came.

They got called away from wrap-up in Alaska to work a dig in Iceland. Spring had come early, and they were summoned to take advantage of the softer ground and dig down another layer.

("What are you really looking for?" he asked, like he already knew why she agreed to come.

She didn't ask why he had come with her. She knew what pursuit looked like.

"I can't explain," she said, as if it answered him.) For two weeks she scooped mud out of her taped-off square and carved bone after bone in bas relief, and all the while she knew she wasn't alone. The mossy tundra had eyes for her, and whenever she was near Mark, under his wolfish eyes, she felt a beast in the forest hating her.

(A wolf knows a wolf.) They were done for the night, back at the rickety two-bedroom house near the dig site, when the wolf came.

There was the single howl as it called her to battle (they both stood up so fast the work table skidded), and then nothing but the wind; the dire wolf is silent when it hunts.

"Stay behind me," Mark said.

Then came the thunder of the charging beast.

It was too fast for her to get away, too fast to hide Mark, too fast to explain.

There was only time to throw open the door and leap (Mark shouting at her to stop), force the change between one breath and the next, so that she furled inside-out and the air crackled with the sound of snapping tendons and the grind of bone.

(She won. She doesn't remember how. All the way home she coughed up bits of the other wolf; spat up bone and teeth and fur.) The fight carried her a quarter-mile from the cabin, and she padded back as the wolf.

There was a chance he hadn't seen her. There was a chance he didn't know.

(No chance.) When she saw him standing in the doorway, the blanket in his hands, she made a high, keening noise that started as a howl, and became-between one breath and another-a human cry.

(Grief.) Her bones seemed painfully soft and frail in her human form; she could hardly feel her blood pumping through such long, twisted veins. She set her weakling jaw against the shaking, but her skeleton rattled inside the meat.

It was worse than the new moon, ten times worse. It was the tree roots erupting through the pavement, shattering the stone.

Mark got both arms under her and carried her inside, out of the ice and the dark. He smelled like snow and detergent and fear, and she didn't know why a smell like that would be comforting to a wolf.

(She didn't know much about love, back then.) He carried her up the stairs and ran a hot shower until the blood and dirt were gone, and his hands were shaking.

(Fear, she thought then. She knows now-desire.) When she came downstairs again, he was standing outside. There was a wolf's footprint in the snow outside the cabin. It was the same length as Mark's foot, and as wide; her claws had pierced right through the snow and dug up four thin sprays of black dirt across the white as she ran.

He pa.s.sed his foot over it, smoothing the snow free of the evidence. She waited, wondering what she would do if he threatened to expose her.

(It was a lie. She knew what she would do. On four legs, she could hunt without thinking.) After a long time, he took a step backwards, closer to her, without turning.

"Does it frighten you?" he asked.

She said, "Always."

When he came at her, the kiss drove her against the door with a thud, and he tore away the blanket as if he wanted some part, any part, of her fight.

She dragged her nails over his back, five thin trails of red against his skin.

The dire wolf that lives in human form spends the day of the new moon curled in a corner, trembling, aching, grinding her teeth as the bones scream for change. The moment of transformation is unbearable (there is always the wrenching cry), but it pa.s.ses, and the bones and the fur and the teeth of the wolf are her relief.

A dire wolf can turn at will, but it's the last line of defense; between pain and death, some choose death.

Changing at every new moon from human to wolf and back can drive you mad. Most dire wolves eventually give in to their true form, and make their homes in forests, or tundra if arctic wolves are nearby, or desert caves. They can go anywhere once the moon has lost its power over them. What animal would stand up to a beast twice as large as a wolf, twice as fast, twice as cunning?

Legend, which looks for monsters within its own neighbors, claim that werewolves are people who achieve the body of the wolf.

This is untrue.

The dire wolf took on a human form; down at the bone, between every breath, each of them is really the animal. The human shape is a useful trick, that's all.

(Adapt or die.) Christopher's waiting at the lab when she comes back.

"Mark says it looks like an Arctic wolf that got on the wrong side of a bear attack," he says. "What are you thinking it is?"

"I think that wolf had a pretty sad end," she said. "Did you find anything else of the skeleton?"

Christopher shakes his head. "We don't have the manpower we used to, but as far as we looked, there was nothing to find. Maybe the head got carried over to where our guy found it."

"Was there any skull? Any other bones?" She thinks about the deep, low temporal fossa-a jaw is easy to disguise, but the skull would be hard to explain.

He shakes his head.

"Where's Mark?"

"Went out looking for you," Christopher says. "I'll call him back in on the radio."

When she's alone, she looks at the jaw under the magnifying gla.s.s, marks on her report the hundred tiny dents where the birds pecked the flesh away, the smooth expanses where the insects got there at last, carrying away whatever was hanging on.

The bone is cool, and smooth as human skin.

Mark opens the door too fast, gets too close.

"I saw the tracks," he says, quietly, so Christopher won't hear. "It's big."

He means, it's bigger than you. His breath is warm on her scalp.

"I'll win," she says.

After a little silence, he says, "I'd forgotten what it feels like to be close to you."

She doesn't know what he means; doesn't dare ask.

The dire wolf was too slow to evolve, everyone knew.

"Poor guys," Alice said (she pitied all the bones). She waggled the saber-toothed tiger skull she was working on, like it was nodding. "The saber-tooth says nature cuts us all down sooner or later. He should know. Poor kitty."

Alice always got punchy near the end of an excavation.

"Nature might surprise you," Velia said, ran her tongue over her teeth.

"Promise me you won't fight," he says.