Notes: Well, here it is, after approximately half a year. The supposed (not all that conclusive) conclusion of this fic. It's mostly character study, really, but that's what it started off as anyway, so I'm quite pleased with how it turned out. Hopefully it's enjoyable and I'd love to know what you guys think!

"I can't do it, I'm sorry." Sebastian schooled his expression back into his usual encouraging smile with lightning speed, but not quickly enough for Jace to miss the flash of irritation across his features. "He's too far away," he snapped, frustrated with his own inability to do what he'd meant to. "We need to be closer to each other."

"You need to be closer," Sebastian repeated, running a hand through his hair, clearly in an effort to compose himself. "Jace, you won't always be close enough to help each other in battle. And if you can't help Alec, then what's the point of any of this?"

Truth be told, even though Jace was aware that he was trying, Sebastian wasn't the most patient teacher in the Shadow world. He didn't like it when anything took too long to work and he liked having to wait without doing anything even less and, to make things even worse, he seemed to have endless energy. Or, at the very least, enough to do this for hours on end without getting bored.

Jace, on the other hand, was exhausted. He could understand the importance of their work here – better than Sebastian himself did, most likely, even if he'd been the one to initiate it – but the constant pushing was far from the best method of encouragement out there.

"Of course I want to be able to help him," he said, doing his best to keep the exasperation away from his voice. "But it's not working. Not yet, anyway."

"It will work," Sebastian said, taking Jace's hands into his own. "You just need to focus and I thought— maybe coming here wasn't a good idea."

"No," Jace hurried to protest. "It was an amazing idea. We would have never been able to do this back at the Institute."

He would have never been able to be as calm as he was here in the Institute. The possibility of being found out would be too great and there were only so many excuses that he could make before anyone who witnessed the things he and Alec were capable of would start being far too obvious.

So they'd come here. As far as Jace knew, Alec was still back at his office under the guise of working and was in fact testing his own abilities with a bit more success that Jace himself had had so far. It made sense – Alec was doing this in the safety of a place where no one would dare to question him as long as he looked focused enough, and he and Sebastian were in the middle of Central Park.

It was strange, to say the least, being here without visiting the Seelie Court or looking for a demon. They were out in broad daylight and neither of them had bothered with glamour – after all, the only people that would see something out of place in their presence could see through it anyway. As it was, Jace found himself feeling almost mundane despite the work they'd come here to do. He knew that that was what everyone around saw when they looked at them – just an ordinary couple in an ordinary afternoon – and the thought was foreign enough to distract him from their actual reason for being here once again.

"Think of it like this," Sebastian spoke again, his tone even more ambitious now. "You can feel it when Alec gets hurt, right?"

"Of course I can." The topic wasn't one he was too eager to delve in despite the fact that Sebastian was the one asking. He'd been able to feel him more easily recently and it wasn't necessarily a good thing - while it was always good to know when one's parabatai was in danger, both he and Alec had agreed that during the last few fights they'd got hurt in, the echo of the other's pain had always been intense enough to distract them from their mission. It wasn't an easy thing to admit, that the bond could be something to be wary of, but it was the truth nevertheless and it was all too easy for it to be ignored when it wasn't explicitly brought up. "As well as he can feel mine."

"Okay," Sebastian nodded, his eyes locking with Jace's with the same stubborn edge his gaze had had ever since this morning. "You know as well as I do that in times of war, not all fights happen at the same time and place. Imagine that one of you gets hurt while the other is too far away to get to him. What would you do then? You can't send him help. You can't heal him. All you can do is hope that there'll be someone else on his side there or - in case there isn't - wait for him to die. That's why we're doing this," he continued, tone pacifying as he squeezed Jace's hand, the gesture almost absent-minded. "You're stronger together than you are apart; we already know that. But if he can send you messages with his mind so that you're more effective in battle and you can heal him through your runes, you'll be unstoppable. You can't let something like that slip just because you're not sure if you can make it."

"You're right," Jace nodded. He didn't want to hear any more potential scenarios; not when he'd only managed to push the thought away from his mind for more than a minute. "Let's try again."

It wasn't just Sebastian's insistence, really. Jace had found his mind straying more and more to similar thoughts recently; the reasonable fear he'd had of losing his parabatai morphing into something much more intense. It was natural, Sebastian had told them when it had been brought up. It was yet another thing he'd read in his father's books: the closer two parabatai were, the more fixated they were on one another. He'd also assured them that it wouldn't get in the way during battle and that it would only aid them further but from where Jace was standing, it seemed more and more like a hindrance every time he decided to focus on it (which wasn't often; the thought was unpleasant enough that he'd purposefully started trying to pay no attention to it. If that was another thing to worry about, then he preferred not to dwell on it too much).

But now, here, Sebastian's smile was blinding and it was almost enough to make him forget his fears in the face of a promise of something that could hold them at bay. "Come on," he coaxed. "Close your eyes. Try to see Alec in your mind; call out to him like you do when you're trying to establish a telepathic connection. He's bound to feel it sooner or later."

Jace had never asked Sebastian where he'd learnt everything he knew about runes and he didn't plan on doing it now. The answer was rarely something pleasant and most often had to do with his father, which seemed to be the worst possible topic when it came to him. His knowledge had been nothing but useful so far, though, and he wasn't about to protest; not even when Sebastian's coaching got a little too much for him to deal with all at once.

Alec seemed to be taking it better. He'd taken to the new task with the same dedication he'd given to any of his studies during their childhood and so far, he'd been doing great with his part of the research they'd started doing on the bond. It had turned out that their ability to reach each other's mind when they wanted to wasn't affected by the distance between them and while they'd realised that the newly sharpened pain from the other's injuries had only started getting worse, they had found out something else too - the same went for the healing runes they used.

Which was what had led them to this. Jace's runes on Alec seemed to be more effective than vice versa and so he'd let himself be convinced that it was a good idea to try and activate Alec's runes through his own from an increasingly great distance. It had worked fine at first, but once they'd left the grounds of the Institute, it had stopped almost immediately and now, from the other end of the city, the task felt next to impossible.

Jace was resolute to make sure that it would work this time, though. Sebastian was right – the better he got at this, the safer both he and Alec would be and in the end, that was what they'd been aiming for from the start.

Correction - it was what he had been aiming for. He wasn't sure whether the same went for Sebastian, who seemed more eager to use it as a weapon rather than a defence regardless of what he said and it wasn't difficult to see that he had bigger plans than just New York. In fact, it had been Jace who'd proposed this place and he dreaded to think what it would have been instead if he'd let him decide. For all his good intentions, Sebastian tended to be far too ambitious.

Jace could still feel his encouraging touch on his hand as he led the stele over his true north rune. They'd picked it for the effect it had more than anything else - it was something that they were sure that Alec would feel, the sudden change of focus too intense to be ignored, and in case he did, he'd let them know immediately. It was a precarious arrangement, but they'd made it work and Jace focused all his energy into that one action, trying to picture the stele's magic flowing through their bond and into his parabatai. It certainly felt different this time around from what it had been like the other times he'd tried it – he could almost see the connection, as if his and Alec's efforts to get closer to one another had finally managed to become tangible despite the space between them and all the obstacles in their way. This was new. New and addictive in a way he couldn't quite describe but couldn't get enough of either.

When he opened his eyes, Sebastian was grinning at him victoriously. He held his phone up for Jace to see the message that Alec had sent them and Jace felt himself smiling too, the sudden burst of pride making him feel far better than he had just a minute ago. He'd done it.

"You did a great job." Sebastian got to his feet and pulled him up. Jace followed in his tracks and only stopped when his boyfriend turned around for a kiss – one that he accepted eagerly. They'd agreed to go to lunch if this worked and Jace was definitely more than ready for that, the magic necessary for the trick he'd just performed too draining for him to wait until they got back to the Institute. "I knew you could do it," Sebastian added, not without a decent amount of pride, and after linking their hands together, led him down the hill.

After all the effort of the morning, the idea of lunch sounded heavenly and the diner they'd found for that purpose didn't disappoint. Jace wolfed down the meal he'd been given while Sebastian picked at his own food on the opposite site of the table, seemingly still enthralled by the progress they had achieved just today. He hadn't stopped texting Alec since then, likely questioning him about the things he'd felt during Jace's final, successful attempt at connection.

There was a reason why he and Isabelle spent so much time together, Jace thought. They both took an interest in the body that was more scientific than anything else and, tiring as the experiments could get sometimes, Jace still found it rather endearing. There was always something new he fiddled with and he was so enthusiastic about it that even things that would have worn out Jace's patience a long time ago - like the constant questions and displays of magic that he wanted, no matter how easy they were to achieve - had turned into something that he did without a second thought.

"What does Alec think about this?" Jace asked between two mouthfuls. "Can it work in battle?"

"He thinks yes," Sebastian said, still not looking up from the screen. "He also thinks that there's something else that could work, but we haven't perfected it yet."

That was another thing - the individual work he did with both of them. He was especially secretive about those particular ideas until something actually came out of them. He insisted that the effect would be stronger if the other wasn't aware that something was going to happen and even Alec, rather averse to surprises most of the time, had agreed. It felt almost like a game sometimes - one that Jace didn't mind playing without caring where it would take them. He never knew what to expect and that made it feel even more like magic and drew him in even further; the constant awareness of how much the parabatai bond was changing and how much stronger they were becoming had swallowed up so much of his time and thoughts that it felt like the most important thing in his life. If Sebastian had been anyone else, he would have worried about him feeling left out, but as it were, he had definitely made a place for himself in their bond and Jace was more pleased with that than he had ever guessed he could be.

It was all in the little things he did to help them move further with their abilities, in the telepathic connection he could now achieve much more easily than the first time they had tried it together. In a way, Jace knew that they would have never got as far as they had if Sebastian hadn't been around to encourage it and the thought was both exciting and a little frightening; that something he and Alec had kept a secret for so long and with such painstaking care had morphed into something they shared with him like it was a given.

It was only when they had decided to leave - well after he had become wrapped up in his thoughts - that Jace noticed that something felt a little off.

"I think it would be better to ignore my own advice this time around," Sebastian started with a rather particular expression - one he usually saved for moments when he wanted to seem apologetic and also enthusiastic enough to lure one of them into whatever new scheme he'd thought of. Much to Jace's discontent, it worked without fail and Sebastian knew that, so they saw it all too often. "Because what Alec's about to do - or what I think he's about to do - goes a little further than our usual experiments."

"Did you have to do this today?" The incredulity in Jace's voice was enough to surprise him as well. He wasn't sure what this was, but he suspected that he was about to find out in the very near future. "After everything we did this morning?"

"Alec thought that it might be a good idea." Sebastian had slowed his pace and Jace followed his example all too eagerly, his body feeling more and more foreign by the second. "If he can pull this off, he'll probably only need to do it when you're exhausted already and need someone else to take over."

"Take over," Jace repeated and he suspected that the exasperation creeping into his voice had become a little more obvious as the apologetic edge to Sebastian's general presence intensified. "Why does Alec always have to agree to the worst possible—"

He trailed off as he stared at his hand with fascination mixed with horror, which then proceeded to spread to the rest of his body when his first instinct was to stop and see what was going on, only to have it still walking. It felt oddly like an invasion to see his legs move without his explicit permission, but he didn't do anything to stop it, more concerned with the mechanics of it happening at all. It stopped soon enough anyway, the foreign – new, not foreign, because he knew exactly who the source was – force withdrawing as quickly as it had appeared and leaving him breathless in its wake.

We've gone too far. He didn't say it, although it was the only logical conclusion. They had to draw a line somewhere and this seemed like the perfect moment, before they'd completely lost track of what was safe and what wasn't. But he couldn't find it in himself to protest; not when he could feel the already familiar edges of Alec's magic settling inside his body, reaching him to the very core and it should have been alarming - this wasn't supposed to happen, things like this were the reason they had been forbidden to want anything different from what they bond gave them - but it felt exhilarating instead and Jace leant against the nearest wall with whatever control he had left over his body, grateful when he felt Sebastian's arms wrap around him.

"This... this isn't like mind reading," he managed to say, closing his eyes at the maelstrom of sensation that reigned inside him.

"No, it isn't." Sebastian didn't sound properly worried yet, but it was close. "Is it too much? If you try, you can probably communicate that—"

"No, it's fine," Jace waved him off. "It's fine, just. Give me a moment." He opened his eyes again, trying to fight the sudden sensory overload – he had felt as if he was in Alec's office for a fleeting instant, and the complete silence in which his parabatai was working was in stark contrast to the streets of New York. "I can see how it can be useful. If I ever think I can't go on for whatever reason, Alec can just give me a hand. And if it's him being hurt, I can heal him with my runes. It's—" He didn't want to admit it since it was all still so strange, but he had to. "It could work. I think it's going to work. How did you—"

"I told you." Sebastian's voice was smooth as silk and there was a moment of Jace feeling completely disoriented - he was in front of him, but he also wasn't in the room at all and Jace's confusion mixed with Alec's satisfaction at his success until he could no longer tell with absolute certainty where he was. If they were going to use this in the future, they would definitely have to work hard for it and even as the thought passed through his mind, Jace knew that they most definitely would - there was no way he could know that they could have this while also ignoring that knowledge because they'd had a rocky start. "Your strength is in the runes and Alec's is his mind. This could develop beautifully if you let him - and me - in. It could save your life one day."

Jace thought about all the times in his life he had wished he could escape his life (his body) even for a little while. He thought about what was being offered to him; what they could do, both in a battle and outside of it, if he'd just let himself have this, and he felt his resolve crumble bit by bit until there was nothing left.

"Yes," he said in the end, delirious and confused and almost ecstatic. "Show me."

Sebastian had finally climbed up on the bed and was leaning on his side, a small smile playing on his lips as he watched them. It was quite a sight, Jace imagined; Alec trailing a line of fervent kisses from his jawline all the way to his stomach, his hands still wrapped securely around Jace's shoulders as he lowered himself even more. They'd both noticed that physical contact felt different now that they'd tried this and even though they hadn't repeated the experiment again today - it was far too exhausting, they had found, and it wasn't like they didn't have enough time for perfecting it in the future - Jace still couldn't quite shake off the feeling it had left in him. Everything felt sharper now, brand new and age old at the same time, and he couldn't get enough of it.

His soul had always been intertwined with Alec's, ever since they had said their vows, but this was different. He was an almost palpable presence inside Jace's body as well as his mind and it made him feel dizzy and overwhelmed and stronger than he had ever been. Each little step they made seemed to affect them differently, as Sebastian had pointed out, and Jace was inclined to agree. When it came to Alec, the changes in their bond had made him faster and more focused and, impossible as it sounded, even more efficient than he'd been before, while Jace just felt erratic - buzzing with energy and riding a constant high that made him itch for a fight at the slightest provocation. They had become far more dependent on each other than the Clave would deem advisable, too dependent, a part of Jace's mind warned him, but it was an old, memorised caution; one that he felt almost ready to let go of.

It was nothing but his father's lessons raising their ugly heads yet again, he could tell that much. The talk about how the only person you could safely depend on was yourself was a well-familiar one but definitely not applicable to the current reality of his life. This was Alec, his parabatai – he could rely on him as much as he could rely on himself, and Sebastian had done nothing but help enhance that further. Content with the thought, Jace reached out blindly to draw him near and grinned when he felt fingers wrapping around his own, a second body pressing against them as Sebastian leant in to kiss him. Any risk he could take was worth it for this. They would make it work one way or another, he was sure of it, and nothing his father had ever said would be able to take that away from him.