Cold takes the crows. The girl finds them fallen, ice and feather, on the frozen stone. Stops to say a word for their little corvid souls. Her voice frosts.

The valley before her lies dead and glittering with rime. The weight of ice has stripped the boughs from all the trees and now they stand like bones. The long glazed road goes on towards the mountains through villages of crushed eaves and crumbled roofs.

What killed you? she asks the crows. Was it the winter?

It should be spring, their dead eyes protest. It should be spring.

It is spring, but the crows know too little of thermodynamics, and she is too tired to explain, even to the clever souls of crows, why the thaw will never come.

I will end the winter, she tells the crows. But I must have you to do it.

They make a papery protest as she takes their feathers for a totem. Thank you, she says.

But the souls of the crows are silent now.

She walks north, her eyes rimmed with black grease against the glare. Her telescope’s brass is cold enough to peel skin and her compass has frozen in its turn, pointing with dead insistence to a north that rings the world.

Beneath her crampons the ice complains into the silence.

After a long while the aurora pulls the sun out of the sky and opens itself horizon to horizon. She makes camp in the open waste. By now she has learned the futility of fire.

Death comes for her in the night, drawn by hypothermia, and she turns it away with an upraised hand. It lopes under the dancing sky, circling her, trampling the reflections of ten thousand stars.

You are mine, it says. You are mine four times over, now. Come with me.

Not yet, she says. Not yet. We made a bargain. My debt can still be repaid. I have the souls of crows to offer—

Death howls, and the moon shivers on its throne of starlight. You are past the worth of crows, Death says. You are past all hope. Come with me.

But she does not lower her hand.

Come to me again when I have killed the winter, she says. They say you are a patient thing. Be patient. I have work to do.

She wraps her frozen furs around her and turns away.

In the morning she draws her sword, pale and curved as the hip of the moon, forged in a time before steel and colleges and the naming of all the physics. She calls it Sabertooth, and it does not frost. She stole it when she broke her vows. Some day soon she will use it to kill the winter.

She practices with it to make sure she is not dead. She is not. But she is slow, weak. The strength is going out of her. The road is hard, and she has turned death away four times.

She feeds herself as she has for weeks: from the totems she has gathered.

The feathers she eats taste of eggshell and high harsh winds, mouse and blood: crow things. It takes three to make her warm. When she lifts the blade again there is no weakness in her arms. When she sets off down the road her legs answer her like wings.

The winter is a dragon. She deduced this, in the libraries beneath her master’s tower, in the silent halls of the college archive. It is all a matter of thermodynamics.

In the winter ruins of a little hamlet, as the sun goes down again, she comes upon a man. He wears bearskin and sings logic to a torch held up to the hulk of a ruined steeple. When his song crescendos, he sets the fire to the frozen wood.

It does not catch. The man stops singing, and the fire on the torch goes out.

Hello, the girl says.

The man looks at her. His beard is dark and frosted, his lips cracked, his breath a slow smoke. She reads mirth or worry in the lines around his eyes.

Hello, he says in a voice salted by a foreign tongue. You look cold.

Save your fire, she says. It warms the winter more than you.

Are you here to kill the dragon? he asks.

I am here to try.

They make a camp. The man pitches a sealskin tent oiled in the fat of midsummer calves. Where is your tent? he asks.

I lost it, the girl says. It was only slowing me.

They sit opposite, in the space between the frozen hide walls. The man shivers and hugs his knees. I need to set a fire, he says, or we won’t last the night.

No fires, she says. I told you why. They help our enemy.

The man considers her. Are you practiced in magic? he asks.

Some. I was a student.

I am court wizard to the High King of the North, he says. My lord King dreamt a prophecy of ruin and dragon fire. I sailed south with four galleons and two thousand men to kill the wyrm while it still slept. But we expected spring, and met disaster.

The girl thinks of men strewn like crows across the ice. How did you survive? she asks.

I have some mastery of fire.

He chews on salted leather, and she sees that his gums have drawn back to bare red bleeding flesh at the roots of his teeth.

And you? he asks. How did you survive?

Your king was right, I think, the girl says. The dragon gathers its strength. Swallows all heat, in transgression of the Second Law. The spring it steals here will become the fire that kills your king.

She lifts a hand as if to cup the cold.

Thermodynamics, she says. Do you understand?

The man shrugs. We place the art of physics above the science, he says. But I have read the journals of your colleges.

She sits in silence, remembering those colleges: stone and cedar dwindling into the snow behind her.

What army did you lead? the man asks.

I came alone, with Death, the girl says.

How did you survive alone?

She looks at him in silence, wondering if he will take the answer she has already given.

The man looks at his trembling hands with a kind of bemusement. I need fire, he says, to melt snow for water, at the very least. Stop me if you must, but I will set one fire.

She considers him. Considers whether there is room in her for compassion—and whether what she feels is compassion after all.

There is another way, she says.

They share furs. He trembles against her, cold and scentless, skin to skin. There are small red spots at the base of every hair on his body. She has been with men before, but the memory does not stir her. There is no appetite in either of them. It is too cold.

She eats ten of her crow feathers. The warmth of summer thermals fills her like a fever and at length the man’s trembling stops. She draws away a little, worried about sweat; damp means death in the cold, another death for her debt.

The man draws breath. You’re a necromancer, he says. You have a pact with Death. That’s how you’ve survived without food or water or shelter.

She nods. He is taller; they cannot even see each other’s eyes. Somehow this troubles her, as if she is being rude.

I sought forbidden things, she says, things I thought would be necessary. I stole from my school, broke my vows, and came to kill the dragon. No one else would.

We burn necromancers in the North, he says.

Don’t you ever listen? she says. I told you: no fires.

He laughs.

After a while he sleeps.

Death circles the tent. She sees the shadow of antlers, tangled like the grove beneath her study, in the towers she betrayed.

You cannot save him, Death whispers; not forever. But perhaps you can save yourself. Is that why you nurse him with the warmth of the souls of crows? So that you may save his life, and offer it to me? Will he be the payment for your debt?

Why have you come? she asks. Is there someone here for you to claim?

Death’s shadow moves as a stag against the watercolor shadows of the aurora. It does not answer.

Then be gone, she says, until he dies. However that might be.

They follow the road toward the mountains where the dragon that is the winter lives. The cold has deepened. The girl remembers a time weeks past when it was still warm enough to snow. But the snow is gone, now scrubbed away by wind off the peaks. When the sun rises, it rises twice, once in the sky and once reflected in the glare ice.

The man eats cured meat from strips in his pack. I’ll need water, he says, sooner or later.

He’s right. She has learned not to eat ice. Melting it to water steals the body’s heat.

She considers him.

Will you last the day? she asks. I move fast. Can you keep pace?

The man nods. Distract me, he says; I’ll keep pace.

She tells him of the tower where she learned the ways of weathercraft. Of the tangled grove like Death’s antlers in the college yard below. Of the long warm winters and the olives and grapes that the students grew. Of the end of those warm winters, and the rising frost. Of the paralyzed indecision that drove her to act.

Why did you decide to break your vows? he asks. I was sent, but no one sent you.

She quirks her lips in thought. I was cold, she says.

I suppose it’s that or take up knitting, he says.

When he smiles she sees that his gums are bleeding.

But he keeps pace.

They make camp in the foothills beneath the mountains, nestled in the shelter of a pass, where the wind breaks.

I think we climb tomorrow, he says, maybe to the treeline. Maybe higher.

The girl nods. No fire, she says; not even for water. Not so close. It sleeps up there, on the peak.

I’ll die without water, he says. I’m not on speaking terms with Death. I still need to drink.

I have a way to quench your thirst without fire, she says.

She beckons for his tin cup and begins to pack it with ice.

Give me your knife, she says.

Blood is salty, you know, he says.

She cuts her palm. It will dilute, she says.

She lets a few drops spill before binding the cut.

I’ve slept without a tent for weeks, she says; I have no frostbite. The pact I made guards my blood from the cold.

Her guess is right. Her blood melts the ice.

He looks into the pink broth.

What will I be drinking? he says. The bargain you made. Can it be passed?

No. It’s just blood. Blood and water.

He looks at her in silence.

Trust me, she says. This isn’t a blood pact. This is just thermodynamics.

He drinks, his eyes closed.

That’s not your sword hand, is it? he says.

No, of course it isn’t.

Can you spare any more?

She counts her feathers before she eats. Forty-one left. Less ten tonight, if she wants to keep him from hypothermia. There is heat in the souls of crows, but she finds herself wishing for the hearts of housecats, the hide of steer left out to pasture.

He watches her in the dark as she swallows ten feathers.  How do you get those down? he asks.

I’m not eating feathers, she says. I’m eating souls. Not as dry.

He looks away. I could go without warmth tonight, he says. Think I’d be fine.

No, she says; don’t. You wouldn’t, and I wouldn’t. We’re too close to risk it.

You have a bargain with Death, he says. What would you risk?

Everything, she says.

Later, after they have fumbled towards some kind of comfort in their passionless embrace, he asks: What price did Death ask of you?

A fair one, for what I gained.

You are an unreasonable person, to play with words at a time like this.

She settles her cheek against his chest. He might take it for affection; he might understand that they have to use as much surface area as they can. She thinks it has grown colder still.

For every death that I turn away, she says, Death asks payment. For the first death the payment was small. But my debt has grown. If I do not pay, it will claim the lives of those I love. I owe it four deaths: the first by fire, the second by thirst, the third by starvation, the fourth by cold.

So it asks that you kill four people?

It asks that I satisfy it. It keeps its own accounts.

It is hard for her to say whether he stiffens in distaste or, perhaps, draws her closer. Bruises mottle his dark skin. Is he jaundiced? It is hard to see.

A necromancer, he says, in the company of a wizard of the North. We are mighty. You will not have to die again.

Later, in the troughs between dreams, she hears him ask: what about you? Does Death ask your life as well?

Of course it does, she says.

Death comes to her as her master, hair knotted high. Death kneels over their cold clutching embrace and reaches towards the man.

I would take him, it says, if you offered him. I would be satisfied.

I abjured you, she says; I cast you out. I will be obeyed. There is no place for you here.

Little thing, Death says, look around you. Look at this land. Where in this land do I not belong?

Where I will you to be gone, she says.

He will be mine soon enough, Death says. You should offer him before I claim him. Or he will be worth nothing to you at all.

The mountain roars. The girl wakes. Finds her sword, her clothes, her furs. Shrugs them on with practiced haste.

The dragon, the man says; the dragon is coming down off the mountain.

The girl steps out into the cold, Sabertooth bare in her hand. Dawn is still hatching but there is enough light to see. The mountain above calves vast, crumbling shadows. Its roar goes on and on. Building. Approaching.

Avalanche, she says; coming down the pass. Leave the tent and run. Run!

She thinks she hears Death laugh among the frozen trees.

The man comes out of the tent with a lit torch.

We can’t run, he says. We won’t make it. Get behind me.

What could you possibly do? she cries.

I am not all cold and thirst and need, he says. I am a sorcerer of the High North. If you know weathercraft, see to the wind. I need air.

They sing their logics back-to-back, his axioms high and shrill over her cant. The wind comes up out of the valley with a roar that almost matches the oncoming ice.

She wants to ask him how long they have, but her eyes and will are set on the air.

He works his torch through a looping lemniscate pattern, roars a Northern calculus, and sets the wind alight. Fire opens around them, gold and black. She can feel it eating the air, devouring the wind.

After so long in the cold, the heat feels like it may crack her open.

The ground trembles.

He cries out and then the world makes a vast, wounded sound that goes on and on. His fire has burnt away all the shadows, and only her wind keeps the steam away. Heat against kinetics, she thinks. Thermodynamics against dynamics. Can he possibly—?

Then it is over. The world falls silent.

She expects to find them surrounded by ruin, torched slag and meltwater. But the ruin is not so great. Just shattered ice, touched by the edge of passing fury.

What did you do? she says.

I brought down the pass, he says. Stopped the slide. Torched what got past. Thank you for the wind.

His face is red with burn, but he grins like a simpleton.

I’m sorry, he says. I know you said no fires.

But it comes at a cost.

He is too exhausted to climb. She feeds him blood and water and he tries to eat salted meat from his pack. She would feed him crow feathers, but for him they would be only feather.

The muscles in his arms squirm and spasm beneath the skin. His jaundice is more pronounced today.

It’s getting worse, he says. At least I think it is.

You’re sick, she says. I’ve seen your gums. What is it? How long has it been?

It started when we sailed south, months ago. It’s the sailor’s disease. I think I have a few days before the convulsions begin. Then I die.

She has read of the sailor’s disease. She has never known sailors. She tries to remember her texts. A vitamin deficiency, the physicians at the college called it.

There is no cure, he says; none that I know.

She touches his lips to silence him. Then forget it, she says; there is nothing to be done.

Do you think the dragon knows we’re here? he says. I could feel it drawing at my fire. Oh, that would be ironic, wouldn’t it? If the fire I raised to save us were the last meal it needed to go north and burn—

Again she touches his mouth. Hush, she says. Your lips are cracked and I can hardly bear to watch you talk.

If the dragon lives, I have failed, he whispers. That’s all that matters. Killing it before it flies. Or comes for us.

After a while she says: You’re right. We need to climb the mountain as soon as we can.

He tries to rise, but he cannot. I’m sorry, he says; I’m sorry I’m so weak. If I have a day to rest—

You are far from weak, she says. Rest if you can. I’m going to watch the sunrise.

Death walks with her through the frozen woods. Death is a white fox and it gambols underfoot. Death is an owl in the dawn sky.

I could make him strong enough to climb, she tells Death. I could give him blood and warmth.

Perhaps, Death says. For a time.

You would take him? she asks Death. You would ask no more of me? Not my mother, not my father, not the boy who was too shy to kiss me? Not even me?

He is a sorcerer of the High North, Death says. He lived when a thousand strong men died. He is the only living thing you know. I would take him, if you offered him, and release you from your debt.

Death is a songbird that sings from the crook of a shattered tree: the only sound but the wind. A joyful sound.

She draws Sabertooth in a flash of old steel. Cuts at the bird, hissing. The atom-sharp blade splits the tree without effort, as it would stone or steel or the bone of dragons.

But Death is gone like smoke.

She finds him standing outside the tent, fully dressed, his torch lit in his bare left hand. It trembles as he shakes.

I thought you would be gone longer, he says.

What are you doing? she says.

He turns to the tent and raises the torch. I am going to burn myself, he says.

He begins to sing.

No! she cries. She tackles him, her crampons ripping at the ice, and he falls. He struggles, cursing, beating at her with gloved fists. Let me go, he says; let me die, damn you.

She grapples for his torch and snuffs it in the ice.

They draw apart. Stagger to their feet. What are you doing? she cries. Why?

You can kill the dragon, he pants. How can you fail, when you cannot die? Save the North. Save your land. You don’t need me. And I will not make the climb—

You will make the climb!

I will not make it fast enough, he says. I will slow you down. And whether now, or with the dragon, or afterwards, I will die.

We all die, she says. Death takes us all.

Unless we give ourselves, he says, to earn something. Or to pay a debt.

The wind off the mountain picks up and draws the mist of their breath away. The lines around his eyes have gathered little marks of frost.

Not for me, she says. You will not die for me.

You meant to kill me, he says; this is more dignified.

I never meant to—

You considered it; I know you did.

He spits blood into the snow. You would have to do it soon, he says; today, maybe. I think the convulsions will start soon, and what will I be worth after that?

No, she says, no, it was nothing I’d decided on—I promise you—

Well, I’ve decided, he says. You move faster alone. And you deserve to live. So.

She closes her eyes and bites her lip until she tastes salt. Her throat closes. She tries to say: You were so brave—

Come, he says. I’m ready.

She thinks of her mother and her father and the boy who was too shy to kiss her. And of herself. She thinks of this man crossing seas to save his homeland; carrying on even after so much death and heartbreak. Weighs those lives against each other.

Understands, perhaps, why Death would see him as fair trade for all of them.

She draws Sabertooth. I cannot bury you, she says. Is that important?

No, he says. I am of the North. The ice will do.

Where? she says.

Through the heart, he says. It’s too handsome a head to lose.

I will save your kingdom, she says. I promise.

She climbs the mountain. The dragon slumbers at the peak. She can feel it suckling at her heat.

She moves quickly, scaling the rock faces above the treeline with bare hands and the teeth of her crampons. She has eaten the rest of her crow feathers and she feels as light as a hawk, as strong as a bear. She will make the ascent before sundown.

Death clings to the stone as she climbs, dangling like a bat. I am content, it says.

When I kill the dragon, she says, spring will come. Life will return. Why do you want that? Why would you help me, when you could have this land of ice?

I crave life, Death says. You know thermodynamics. All life is inefficient. All life hastens death. Entropy is the necromancer’s creed.

She kicks at a foothold, testing it. I’m not doing this for you, she says.

What matters is that you do it, Death says.

She climbs on, towards the dragon.