The city of Virelle burned gold in the dying light, its spires catching fire the way they did every evening, when the sun sank low enough to turn glass to flame. From the high terrace of the Frostmere embassy, Princess Isolde Varn watched the light die and thought, not for the first time, that she hated beautiful things. Beautiful things had a way of ending.

"You're scowling at the sunset again," said a voice behind her. "It hasn't done anything to you."

"It's setting," Isolde said, without turning. "That's enough."

Her handmaid, Wren, made a small sound of exasperation and did not press further. She knew better, after eleven years, than to ask the princess of the Frostmere why sunsets troubled her. Everyone in the Nine Courts knew the story, or thought they did: the ice-realm princess who did not feel things the way ordinary people did, whose blood ran cold enough to still a heart with a touch, who had never once been seen to cry.

They were wrong, of course. Isolde felt everything. She simply did not let it show, because in her family, showing was the same as bleeding, and bleeding was the same as dying.

Below, in the embassy courtyard, a commotion rose — hooves on stone, a herald's horn, the particular hush that fell over a crowd when someone important arrived. Isolde leaned over the balustrade, more from habit than curiosity, and saw him.

He rode a horse the color of dried blood, and he wore no crown, no circlet, nothing to mark rank — only a coat the deep red of banked coals, and a manner of sitting a horse like he owned every road it had ever walked. When he dismounted, he moved like heat rising off summer stone: unhurried, certain, faintly dangerous.

"Who," Isolde asked, "is that?"

Wren followed her gaze and went very still. "That," she said slowly, "is Kaelan Draven. Third son of the Ashwind throne. They're saying he's here to negotiate the water-rights treaty."

"They're wrong," Isolde said. She didn't know how she knew. She simply did.

She was right, though it would be three days before she learned why.

The negotiations were tedious, as negotiations about rivers and borders always were, full of men twice her age arguing about things that would outlive them all. Isolde sat at her father's right hand, silent as she had been trained to be, and watched Kaelan Draven watch everyone else.

He was good at it — better than good. He let the Ashwind delegation's chief minister do the talking about grain tariffs and grazing rights, and simply observed, his dark eyes moving from face to face like he was reading a book everyone else pretended wasn't open. Twice, Isolde caught him looking at her, and both times he did not look away, only held her gaze a moment longer than propriety allowed before returning, unhurried, to the matter at hand.

It was insolent. It was thrilling. She hated that it was thrilling.

On the third evening, she found him alone on the east terrace, uninvited, drinking wine that was not his to drink, looking out over the frost gardens that grew nowhere else in the world but here, where Frostmere magic kept the air cold enough for silver ferns and ice-roses to bloom year-round.

"You're not supposed to be here," she said.

"Neither are you, technically." He didn't turn. "Isn't this your father's private garden?"

"I am his daughter. I'm allowed."

"And I'm a guest who got lost." He finally looked at her, and there was something warm and amused in his face that made her want to simultaneously step closer and set something on fire. "Though I confess I wasn't lost. I wanted to see if the ice-roses were real. We don't have anything like them, where I'm from."

"Where you're from, I imagine, everything grows too fast and burns too bright and dies within the season."

"Now you're just guessing."

"I'm not." She came to stand beside him, close enough that she could feel the warmth radiating off him — actual warmth, not metaphor, the particular heat that Ashwind blood carried in it like banked fire. It should have made her uncomfortable. Instead, absurdly, it made her want to lean into it, the way you lean toward a hearth on a winter night. "Fire realm. Everything urgent. Everything now. Your people don't plan for winters that never come."

"And your people," he said, "plan so carefully for winter that you forget to have summers at all."

She turned to look at him properly then, and found he was already looking at her, and something in her chest did an unfamiliar, unwelcome thing — a lurch, a warmth, a crack in ice she had spent twenty-three years keeping whole.

"You're not here for the water treaty," she said.

"No," he admitted. "I'm here because my father is dying, and when he dies, the throne of Ashwind falls to me, and I intend to make sure that when it does, there is no war between our two houses. Your father has been making noises about the southern trade routes for a decade. I came to see for myself whether Frostmere actually wants peace, or only the appearance of it."

"And what have you decided?"

"I've decided," he said, "that I don't much care what Frostmere wants. I care what you want. You're the one who'll rule here one day. Not your father. Not some minister. You."

No one spoke to her like that. No one dared to see her as anything other than a piece on a board, a treaty waiting to be signed in the shape of a woman. She should have been furious. She should have called for the guards.

Instead she said, "I want the ice-roses to survive. I want my people to stop being afraid of everything that isn't cold. And I want—" She stopped herself.

"What do you want?" His voice had gone quiet, low, close.

"I want," she said, "to feel something that isn't duty, just once, before I die."

He didn't touch her. That was the strange thing she would remember later — that first night, standing so close she could count the small scar above his left eyebrow, he did not touch her at all. He only said, "Then let's start there," and somehow that was worse, and better, than any touch could have been.

He left within the week, called home by his father's failing health, and Isolde told herself it was a relief. Diplomats did not fall for foreign princes. Princesses of Frostmere did not lie awake replaying a conversation about ice-roses. She had duties, treaties, a coronation to prepare for eventually, and none of it had room in it for a man with fire under his skin and something dangerously like understanding in his eyes.

And yet.

The first letter arrived a month later, sealed in red wax stamped with a small, unofficial sigil — not the Ashwind crest, just a flame, drawn freehand, almost like a joke.

Isolde —

My father is dying slower than expected, which the physicians tell me is either good news or very bad news, depending on which day you ask them. I find myself thinking of frost gardens, which is inconvenient, since we have none here, and also of a particular argument about summers and winters that I have not managed to win in my head even once since I left.

Tell me something true. Not diplomatic. True.

She should not have answered. She told herself this while she was already writing the reply.

Kaelan —

Something true: I have never once, in my entire life, been allowed to lose an argument. My tutors let me win. My father's ministers let me win. You did not let me win, and I have thought about that more than I would like to admit.

Something else true: the ice-roses are dying earlier this year. The winters are getting shorter. No one else has noticed yet, but I have. I don't know what that means for us, but I don't like it.

— I.

The letters became a habit, then a hunger. Isolde found herself waiting for the courier's bell with an eagerness she despised in herself and could not stop. Kaelan wrote about his father's slow decline, about the weight of a crown he wasn't ready for, about a childhood spent being the spare, the third son, the one no one expected anything of — and how strange it was to suddenly matter. Isolde wrote about the loneliness of being the only daughter of a house that measured love in composure, about a mother who died when she was seven and a father who had never once asked her what she wanted.

They were not diplomatic letters. They were the truest things either of them had ever put to paper.

I think, Kaelan wrote, six months in, that I have been in love with you since the frost garden, and I have been trying very hard not to say so, because you are the crown princess of a nation that has spent three hundred years distrusting mine, and because saying it makes it real, and real things can be taken away.

I am saying it anyway. Do with it what you will.

Isolde read that letter eleven times before she allowed herself to cry — the first time in sixteen years — and then she wrote back four words:

Come back. I'm cold.

He came back in winter, which the Frostmere court found significant, since Ashwind royals did not travel in winter if they could help it — the cold did something to fire-blooded people that made them sluggish, dulled, half themselves. That he came anyway, shivering under three cloaks and looking faintly miserable and entirely unwilling to leave, told Isolde everything the letters hadn't quite dared to say outright.

"You look terrible," she told him, meeting him in the same frost garden, the ice-roses brittle and half-dead around them.

"I feel terrible," he agreed, teeth chattering slightly. "I would like it on the record that I am doing this entirely for you, and I expect to be compensated in warm rooms and possibly a fire the size of a small house."

"You could have written that you were coming."

"I wanted to see your face when I did it. Was that face worth the frostbite risk?"

She looked at him — truly looked, the way she had been forbidden to look at anything her whole life, without armor, without composure, without the careful distance that had kept her whole and untouchable and alone — and felt the last of the ice around her heart give way like a river breaking in spring.

"Yes," she said. "It was worth it."

He crossed the space between them then, slowly, giving her every chance to step back. She didn't. When he kissed her, it was not gentle — it was fire meeting frost, urgent and hungry and years overdue, his hands finding her waist like he'd been aching to for a year, hers curling into the front of his coat like she might fall without the anchor of him. She had spent her whole life being told that fire and ice could not coexist, that they consumed each other, that this — this exact collision — was a catastrophe waiting to happen.

It did not feel like a catastrophe. It felt like the first true thing she had ever done.

"I have spent a year," he murmured against her mouth, "trying to talk myself out of this."

"Did it work?"

"Not even slightly."

"Good," she said, and kissed him again, and the ice-roses around them, half-dead a moment before, opened one by one in the dark like they, too, had been waiting for permission to bloom.

It was not, of course, so simple as a kiss in a garden. Word of the Ashwind prince's midwinter visit spread through Virelle within a day, and by the week's end, half the Nine Courts had an opinion about it, most of them unkind. Isolde's father summoned her within the hour of hearing the rumor, his face carved into the particular stillness he wore when he was more furious than he would ever admit aloud.

"Three hundred years," he said, "of careful distance between our houses. Three hundred years of peace built on the understanding that fire and frost do not mix. And you would throw that away for a boy with a pretty face and no throne of his own yet?"

"I would throw nothing away," Isolde said, and was proud of how steady her voice came out. "I would build something new. A marriage between our houses could end three hundred years of careful distance, Father. It could end it in the right direction."

"Or it could end in war, if his people or mine decide the union is an insult rather than an alliance."

"Then we will make sure it isn't an insult," Isolde said. "I am not asking your permission. I am telling you what I intend to do, because I love you, and because you raised me to rule, and ruling means making the hard choice and living with it — not hiding behind three hundred years of fear."

Her father was silent a long moment. Then, quietly, in a voice she had not heard from him since her mother's funeral: "Your mother would have liked him. She always said this family kept its heart in a vault, and one day someone would need to break in."

"Does that mean you'll allow it?"

"It means," her father said, "that I am tired, and old, and that you have never once asked me for anything in your entire life until this moment, which tells me it must matter more than anything else ever has. Bring him to the winter court. Let the ministers see what I already see."

"And what do you see?"

"A girl who finally looks alive," her father said, and looked, for just a moment, unbearably sad and unbearably proud all at once.

Ashwind's court was harder to win. Kaelan's father died three weeks later, and Kaelan ascended a throne he had spent his whole life not expecting, in a kingdom whose ministers were no kinder to the idea of a frost-queen than Frostmere's had been to a fire-king. There were councils. There were threats of withdrawn support, murmurs of rebellion, an assassination attempt in the second month of his reign that left Isolde's own guards standing between her and a poisoned blade meant, they later learned, for either of them, whoever it caught first.

Neither of them wavered.

"They think we'll destroy each other," Kaelan said, one night in the weeks after the attempt, holding her too tightly, like he was still afraid the blade had found her after all. "Fire and ice. They think it's inevitable."

"Let them think it," Isolde said. "We know better."

"Do we?"

She took his hand — his warm, scarred, steady hand — and pressed it flat against her chest, over her heart, which beat fast and human and entirely unfrozen. "Does that feel like destruction to you?"

"No," he admitted, some of the fear easing out of his shoulders. "It feels like the only thing I've ever been sure of."