Notes: My first foray into this ship and I haven't written Jonathan in a while; hopefully I've made it work well enough. Based on a prompt on tumblr; I kind of left myself an open ending just in case. As always, feedback is welcome!

Nothing had worked. No arguments, no begging, no offers of better matches that would benefit the family more had helped. No matter what Jace had done, his grandmother had been adamant: he would marry into the Morgenstern family and, more importantly, he would marry Valentine Morgenstern's son. The girl wasn't good enough for him, apparently; second in line to the riches and the lands her brother would inherit and regrettably capable of getting pregnant.

It was Jace's incredulity at the mention of this as a flaw – didn't Imogen want grandchildren who could inherit their domain? – that had finally led to him accepting the plan she'd proposed.

"Valentine's power won't last forever," she'd said when he'd asked. "Either one of his subjects will kill him, or one of his children will. He's always thought that he can terrorise everyone into submission, but he's walking on thin ice and when it cracks, it'll be the perfect moment for us to step in. Might as well use the chaos to our advantage." She'd neared him and had cupped his cheek in her hand like she always did when she thought he only needed a little push. "He killed your parents and he kept you captive for a decade. Don't think I've forgotten. But you will go there and be the embodiment of peace for as long as you need to before the right time comes. You keep talking about your friends the Lightwoods, but what good would a union with them be? We already have their support. I want you to make sure that the Morgensterns will open their doors for us no matter what. Is that clear?"

Jace nodded, no longer bothering to speak. She was still the ruler of their domain and he couldn't have refused even if he'd wanted to; it seemed like a much more graceful option to leave on his own free will.

"Yes." If she was right, he would be back home soon enough, possibly still capable of finding himself a proper match. And if she wasn't... well, it wouldn't do to think so far ahead just yet.

o.O.o

The wedding was, much to Jace's dismay, one of the biggest events of the year across all three kingdoms. The Lightwoods had been invited too, just as expected, and so far, Jace had only managed to find comfort in their presence. Alec and Izzy – their older children and Jace's oldest friends – were by his side up to the moment when they had to enter the hall. Alec specifically had gone out of his way to make sure that he could still rely on them despite everything.

"You can ask for help any time you need it," he said for what had to be the thousandth time. "You're his husband, not his prisoner. If anyone here hurts you—"

"I can look after myself," Jace cut him off when he realised just how riled up his friend was getting. "Don't start a war before I'm even married, please."

"Of course I won't." Despite his reassurance, Alec gripped his shoulder as if he was afraid that Jace would somehow dissolve into thin air otherwise. "Promise me you'll write often."

The only thing that Jace wanted to promise him was that this likely wouldn't last long; that he would be back home soon enough, even if it was with the intention of starting a war. But he'd been instructed to keep it to himself and right now – before he'd even said his vows – he only owed allegiance to his grandmother, no matter how much he wished to change that. "I will," was the only thing he said instead, giving Alec a quick hug to dissipate any worries he might have had. Not that they were unfounded, really; Jace was the first to admit that he was terrified, but not out loud. That just wouldn't do. Plus, it was almost time for him to walk into the hall and face his future. Showing even a trace of fear would be unacceptable.

"Let's go," he said, pulling Alec along until they were just in front of the main entrance. He let go of him, then – he couldn't be seen accepting someone's support, not here – and headed for the hall as briskly as he could force himself to. No reason to give any onlookers and excuse to doubt him. He'd made his decision a long time ago, after all.

o.O.o

To a certain degree, Jonathan was everything Jace had expected him to be.

Despite the fact that the man was sitting right next to him, he could get a good look at him in the dimmed lightning of the main hall. He was dressed in ceremonial white just like Jace himself and – just like Jace – seemed to drown in the colour which only served to make him look paler than he already was.

The similarities ended there. After his first glimpse of him at the altar, Jace had noticed that his eyes were mismatched too – likely an after effect of Valentine's experiments as well – but it was different with him; the blue of his left eye sharply contrasted by the darkness that had taken over the right one entirely. Jace had heard enough rumours to know that Jonathan's father had practiced dark magic more than often during his upbringing and he saw the truth of those stories now. It wasn't like he'd needed to see the proof – he knew what the consequences of magic overuse were, had known for years – but it was strangely comforting to realise that he hadn't been the only one. Comforting and terrifying, if the other legends he'd heard – the ones of Jonathan's short temper and cruelty towards anyone who refused to submit – were also justified.

Jace jabbed his fork into his meal with a little more force than strictly necessary. He'd lived in this very castle for the first ten years of his life and even if his access to most of it had always been restricted, it still felt far too familiar for his liking. For ten years, Valentine had let him believe that his was his only son and that all the warlocks and magicians and faeries he brought to him were only there to help make him stronger and more powerful and more capable of facing their enemies. And Jace had listened; had went along with any mission and exercise he'd sent his way no matter how difficult or how near impossible they proved to be. And he had become better, even if it'd been a slow process, from the combination between his own efforts and his father's magic.

It had all fallen apart a month before his eleventh birthday when their carriage had been attacked and he'd been abducted by the Lightwoods's army. Or at least, that's what he'd seen it as back then, an abduction, until he'd met his grandmother and she'd explained everything to him – about his parents and their deaths and the fact that he really was the heir to the crown; it just happened to be a different one from the one he'd imagined. He hadn't met Valentine since that day and he didn't intend on changing that now; content with the several tables's worth of distance and all the people between them. It was an illusion of safety, nothing more, but it was all he could afford.

"Aren't you enjoying the food?"

And then there was Jonathan, with his unreadable eyes and the neutral smile he'd kept up since the beginning of the entire debacle. Jace had learnt all about him in the months after he'd been brought back home and while he'd imagined meeting him plenty of times, he'd never expected that it would happen like this. It had always been different scenarios – battles, usually, in an inevitable war between their two kingdoms – and he couldn't deny that he'd wanted to learn more about him, the desire only growing stronger with the far too frequent remarks from people who'd met them both who swore that there was an uncanny resemblance between them, the only thing setting them apart being Valentine's choice to use dark magic to enhance the other Jonathan's abilities.

Jace shot a look in his direction now – quick, barely noticeable, brief enough for him to not feel like he'd lost the unspoken challenge to ignore his groom as much as etiquette allowed him – and couldn't determine whether he was just making small talk or had something else in mind. He knew what Imogen would have said, but she wasn't behind his shoulder reciting his lines for him this time. It was up to him to decide, so he took the bait.

"It's fine." It felt like dust in his mouth, but Jace was sure that the cook wasn't to blame. He didn't really feel up for a conversation, even less so when he could feel everyone's eyes on them. His fellow countrymen – mainly nobility invited by the Morgensterns to celebrate the occasion – had no way of knowing that this wasn't him turning the other cheek and he could feel it every time they looked at him.

"Then what is it?" Jace suppressed a flinch at the sudden touch to his elbow. Long fingers wrapped around his arm and the squeeze that followed would have felt like sincere concern from anyone else. Anyone who actually knew him, even, and that wasn't the case here. It didn't matter what vows they'd spoken to each other just an hour ago; not when everyone knew that love wasn't what had brought them together. Pretending otherwise seemed ridiculous and Jace made sure to say so with his eyes if not with anything else. It was better that way, wasn't it? He doubted that Jonathan expected anything but hostility anyway, so he might as well be upfront about it.

"It's been a long day," he said pointedly, nudging his plate away. "I'm exhausted."

"We can leave, if you'd like." Still smiling, Jonathan got up and offered him a hand. "I'm sure no one would mind."

Plenty of people would mind – his grandmother most of all, Jace suspected – but he was past caring about that. He made to stand up too and he could feel her glaring daggers at him because he was leaving his own wedding feast too early and people would talk if he tried to evade his husband, but that wasn't what made him stand on edge. It had more to do with Jonathan's sister, sitting by her father's side, whose gaze followed him with no small amount of anxiety. She looked at her brother and then, before Jace could make sense of the wordless communication between them, she seemed to relax at least a little in her place.

Indirect or not, this was as much comfort as Jace was going to get and he pushed his chair away from the table decisively, getting to his feet before he could change his mind or pay too much attention to the countless pairs of eyes that turned in their direction.

Let them talk, Jace thought viciously. His people deserved to know that he hadn't betrayed them.

o.O.o

The walk through the corridor to their personal chambers was a quiet one. Jace could feel Jonathan's presence by his side, but he was doing his best not to acknowledge it, focusing instead on the twists and turns they'd made from the great hall to this part of the castle. He would need it in the future, he supposed, and this was as good a time as any to learn.

"Your room is on the opposite side of mine," Jonathan spoke suddenly. "So you can come to me if you need anything. Of course," he continued, "there are the servants too, but they don't know the place as well as I do."

Whether Jonathan realised it or not wasn't clear, but Jace had spent enough of his time around the staff in his own home to know that his last statement was likely a lie. The servants's job depended on knowing the castle they'd been hired in like the back of their hand and they usually knew their way around it better than even than their masters. Still, Jace appreciated the attempt at conversation for what it was and flashed a customary smile in return. "I'll keep that in mind."

"My father told me about you," Jonathan blurted out suddenly, like he'd been trying to keep the words at bay all night. "While you still lived here. I never understood what made you so special."

Jace froze in his tracks, suddenly unwilling – and unable – to continue. "He did?"

Jonathan just hummed in response, leaning again what Jace assumed was the door to his bedroom. "When he told me that it was you I was getting married to, I thought that it could be interesting. I thought that you could be a match for me. But you don't even want to be here, do you? You hate all of us."

"Of course I do." The unexpected blunt honesty on Jonathan's side was enough to bring Jace's guard down and invoke the same in him, protocol temporarily forgotten. "Valentine imprisoned me. He killed my parents. I'm just doing what needs to be done." Regardless of what that was. It was astonishing, to think that Jonathan had ever thought of him as anything but a rival, but not quite as strange to picture. The Morgensterns knew that they'd won the day Valentine had killed Stephen and Céline and not much had changed since then apart from both Jace and Jonathan reaching marriageable age. Come to think of it, Valentine was probably delighted to have both of his experiments under the same roof and had taught his son to think the same way. It wasn't difficult to imagine what he'd said to him after the years Jace had spent in the man's care. He must have convinced him that he was alone in the world and had made him agree to this with the promise that that would change with Jace's arrival. It would be so typical of him.

"Of course," Jonathan echoed. "You're still loyal to Imogen. What for? She sold you off to us." It didn't seem to be intended as an insult, but it made Jace's blood boil nevertheless.

"No one sold me off," he snapped, any pretence of patience that he'd managed to maintain so far finally starting to crack at the edges. "I wouldn't be here if I had refused to be."

It wasn't exactly a lie, but it wasn't the truth either and the pleasant surprise colouring Jonathan's features felt almost like a compliment. "So you do have a spine after all. Good to know." His smile was as contained as it had always been so far, but there was something new to it now; something unnerving in its unfamiliarity. Unnerving was good, though – it was something Jace could work with, unlike the terror that had reigned over him before he'd arrived here. "I definitely want to see what you're capable of. Meet me here tomorrow morning at sunrise. If you're to be my husband, you'll have to learn how to work with our army."

It was an order more than anything else and indignation rose up in Jace, the taste of it bitter in his mouth. "Would you mind if we postponed that? It took us three days to get here." Three overly uncomfortable days of sleeping in a carriage over the rocky roads between their kingdoms and, while Jace knew that he would still be in fighting shape tomorrow, refusing felt like a small victory. He knew that he would have to be patient, but he hadn't been instructed to take everything in stride in the meantime and he didn't intend to.

Jonathan pursed his lips, but gave him a curt nod eventually. "Take your time." He reached up, one of his hands cupping Jace's face and a smile curling his lips as he felt him stiffen at the unexpected contact. "You don't have to worry. I'm never going to touch you." Unless you ask me to. The clarification was plain in his voice, just like the faint trace of mockery that preceded it, but he didn't say anything else. Instead, he slipped a key into Jace's palm and took his own out of his dinner jacket's pocket. "Good night, Jace." Even his name was heavy with meaning Jace couldn't fully understand yet, but he didn't have time to ask: Jonathan quickly disappeared in the darkness of his room and left him to stare at the closed door, more at a loss than he'd felt all day.