Notes: Written for the prompt, 'on the edge of consciousness'.

One of the endless downsides of being sent to missions at night (which wasn't a rare occurrence - most demons didn't survive on sunlight and hunting them down in warehouses was no one's idea of a good day in the field) was the fact that Jace was expected to go to bed as soon as he came back to the Institute.

Of course, the same thing applied to everyone else as well - it was just how their regimes were distributed for maximum efficiency - but Alec didn't seem to have a problem with it. Once they'd returned from their latest hunt, he'd just taken his gear off and snuck into bed, leaving Jace to his own devices.

Sleeping in Alec's bed was always a risky move, but they usually did it regardless of that. They'd got used to it altogether too easily, but it was fine as long as they were careful about it. And they were - they were painfully careful. They locked the door in any way known to mundane or shadowhunter and on most nights, Jace was too content with their arrangement to think about the danger they'd so willingly put themselves in.

The night wasn't different from any other and yet, the bed somehow felt too small this time around. The battle runes were still burning on his skin, making it even harder for him to fall asleep and soon enough, Alec picked up on that.

"Are you okay?" he asked, turning around so that they could be face to face. "I thought you said you were tired."

"I was," Jace admitted. "But now it's just- I can't sleep. Sorry," he added when he realised that if it hadn't been for him, his parabatai would have probably been asleep already, but Alec waved him off.

"It's fine, he assured him."Want me to tire you out?"

The suggestion was made in a tone so casual that Jace was almost surprised that over the last few months, Alec had gradually become so open about everything he thought. "You don't need to," he said, carefully avoiding the question. Yes would have been the honest answer, but he didn't want to be selfish.

Never one to back down, Alec nuzzled Jace's cheek affectionately. "I want to," he insisted, propping up on his elbows so that he could be close enough for a kiss.

Jace leant into it eagerly, closing his eyes as his hands made their way to Alec's shoulders. This was what he'd needed. This, or another hunt, and he definitely knew which one he preferred.

"Just lie down," Alec murmured when Jace tried to sit up. They were so close that Alec's smile was slightly distorted when Jace opened his eyes again, but it was enough for him to see the already familiar combination of fondness and mischief in his parabatai's eyes. "I know what this feels like."

Jace suspected that every Shadowhunter was familiar with the feeling of leftover effects from their Marks. It didn't happen all that often, but sometimes, if the hunt they'd gone through hadn't been intense enough for all the magic to bleed out from the runes they were left feeling restless and frantic and twitchy. Everyone had their own method for dealing with that, but Jace doubted that any of said methods could compare to the ones he and Alec had thought of so far.

Alec was different. He absorbed rune magic so easily that they never seemed to last that long, but now some of his own calm managed to get through to Jace, washing over him through their bond. He couldn't tell if it was intentional or if Alec was doing his best to help without even thinking about it, but he didn't have it in him to keep pondering the idea when he felt the weight of his parabatai's body over his own.

Alec was warm and heavy and grounding and Jace closed his eyes again, eliminating one of his senses in favour of all the others. Everything felt much more real that way; the feeling of Alec's tousled hair tickling his skin as Alec left a trail of kisses down his neck, making a pleased sound of his own when Jace's fingers found their way into the dark strands and pulled, light enough not to hurt him but sharp enough for him to feel it.

For someone who'd been nearly asleep only a minute ago, Alec was surprisingly enthusiastic. He bit down gently on Jace's shoulder and Jace's sudden intake of breath earned him a quiet, self-satisfied laugh from his parabatai. Alec loved getting him all riled up and when he was in the right mood, he could be downright cruel about it. Jace's currently hazy mind could recall a few memorable occasions in which Alec had almost reduced him to tears and he hoped that it wouldn't all boil down to that tonight. He felt like a coiled spring and every little touch fuelled the fire in him even further. Whatever Alec had planned, Jace wanted it fast and preferably now. His body had latched up onto this new promise of something pleasant, be it a fight or something far different, and Jace was more than ready to obey it.

As if Alec had read his thoughts - and maybe he had; Jace had yet to rule out the possibility given how in sync they were about almost everything these days - Alec lifted up from the bed slightly and shifted his body lower, one of his hands running down Jace's chest. Jace shivered at the cold touch but didn't flinch away; especially not when his parabatai kissed him again. His kisses were short and breathy and Jace found himself trying to reach for him every time he pulled away, too far gone to focus on anything else.

It didn't take long for him to realise that that was exactly what Alec had wanted. Alec's fingers - warmer now that he'd leeched off of Jace's body heat - wrapped around his cock without any warning whatsoever and Jace gasped into the kiss, accidentally biting on Alec's lower lip hard enough to feel the heavy taste of blood in his mouth.

"Sorry," he whispered but Alec was already shaking his head.

"It's okay," he said, leaning down for another quick peck. "I should've warned you."

"No, you shouldn't have." Jace wasn't sure if he was making any sense anymore, but he didn't particularly care. His parabatai rune was warming up in a way he'd got used to so much that he'd started to cherish it and he bucked his hips into Alec's touch, eager to get more; more of the ocean of sensations Alec somehow managed to drown him in every time.

He could feel whatever magic was left in his temporary runes finally start to sputter out, prompted by the chaos that reigned in his body and mind. The rush was the same as in any battle and Jace smiled at the thought, throwing his head back as Alec's strokes, faster by the second, brought him closer to the edge. The rush was the same, but everything else was far better.

Alec could feel it too, of course he could; the feelings passing through their bond always went in both directions, and he seemed to double his efforts. On the next upstroke, he swiped his finger over the head; a feather-light touch, but enough to get the right response from Jace's worn out body and Jace buried his head in his shoulder in a last attempt to keep quiet as he came.

His heart was still racing as he found enough energy to open his eyes, only to close them again with a groan when the first thing he saw was Alec licking off his come from his fingers. Too much. It was too much, and if he didn't know better, he'd have suspected that his parabatai was enjoying seeing him as oversensitive as he was.

Thinking of which.

"Do you want me to return the favour?" Jace offered and was only slightly disappointed when Alec shook his head.

"I'll be fine. Think you can go to sleep now?"

Jace considered the question for a moment. There was no trace left of the restlessness he'd felt before and his body felt heavy and pliant and more boneless than it had in quite a long while. It was more pleasant than he'd have expected it to be.

"I think so," he conceded. "Thank you."

"You don't need to thank me for that," Alec scoffed, but his expression softened when he reached out to ruffle Jace's hair. "Come on, you need the rest," he added as he headed for the bathroom. "I'll be back in a tick."

Jace was asleep before he heard Alec close the door.