One ShotJem/Rose with occasional glances at William, Tessa etc.

Sort of AU actually more like UA – Universal Alterations… not Alternate Universe, Yes. Thank you Tumblr for that UA suggestion use.

I really hope that you enjoy this.

Personally I love writing JEM/OC, and I've loved writing with my character Rose, and I would absolutely love it even more if you guys could review if you liked this or not. Thanks babes. x

Plot – Jem and Rose are training one day when they get a fire message at the London Institute, there are ravener demons running around the streets nearby at night. Being the only two shadowhutners currently at the institute besides a pregnant Charlotte the two set out on the mission to protect the mundane population in the surrounding area and get rid of the demons.

Rose flipped backward, and brought her wooden sword down blocking Jem's attack. The two continued to spar like this for the next fifteen minutes or so, sweat beading down the back of her shirt as they tried to block each other's advances. Jem knocked Rose's sword to the side in the end, ending the training session. Even though he beat her this time- well again; she didn't mind. In fact she loved it when he won. It showed her that he wasn't one for letting the girl always win, just to make them feel better. She was happy that he treated her like an equal. She brushed her dark hair out of her eyes, picking up the sword off the floor and placing it in its correct storage place along the wall of weapons. That was the end of their third session this week alone. Usually they'd do individual training or William and Jem would hang out in there together, teaching each other new moves and enjoying each other's company.

"That was amazing; we have to do it again sometime." She blew out with a heavy breath as Jem smiled at her. Jem had suggested to her the previous day that they should spar together sometime without having the accompaniment of William and his unwanted and inappropriate comments about their friendship. Though William's scandalous opinions of Jem and Rose's relationship had gotten her thinking about it more and more. But then she realised that it was really silly of her to go that far. Jem would never reciprocate those profound feelings she harboured for him… would he? If Rose was perfectly honest with herself she would assume that Jem was going after Tessa if anyone. She shrugged the thoughts away and then was about to fetch a cup of water to cool down with when suddenly a very pregnant Charlotte ran- more like waddled into the training room with a fire message in hand and a panicked expression upon her face.

"Rose, Jem there's been an attack." And that's all charlotte had to say before the two threw on some gear, drew their runes and were out the door ready to protect the institute and those living within the area.

"Come on this way, it'll be faster." Jem motioned for Rose to follow him through countless alleyways and abandoned buildings, leading to their destination within a matter of minutes. As they arrived Rose noticed that it was way to quiet for an attack. There was no screaming, no one in danger and most confusing of all, no ravener demons.

"Jem, are you sure we're in the right place." She asked placing a hand on his shoulder and when he turned around to tell her they were, he was suddenly pulled back into the dark alleyway. Rose's first instinct wasn't to scream or cower in fear, but run into the dark and find Jem.

"JEM." Rose screamed, and soon whipped out her bow and arrow and aimed for the dark. She saw the shadow of what seemed to be a demon and fired. Moments later Jem came stumbling out of the alleyway with black ichor staining his gear, but was fully intact. He drew his seraph blade and the two stood back to back, scanning the vicinity to make sure there weren't any more surprise attacks.

"You okay." Jem asked, as the two carefully examined the area.

"Shouldn't I be the one asking you that?" Rose said sarcastically, and just as she did a whole range of different demons emerged from the dark shadows revealing their enemy. There was a mixture of shax, ravener and shape-shifting demons before them. A total of 7 stood around the young shadowhunters, encasing them in a circle. Rose had her bow ready to attack, and Jem his two blades wielded in both hands. The two looked at each other and nodded, silently communicating before they attacked, getting the advantage.

Jem's blade swiped through the air, slicing through at least two or more demons at once, his advances mesmerizing, somehow even more so graceful than Rose shooting out multiple arrows hitting the pressure points of the demons. Though Rose wasn't fast enough, and a colossal claw struck out on the side of her stomach, slicing through her gear as though it were paper and getting deep within her skin. She hissed at the burning pain and pushed the injury to the side, focusing on just killing the damned thing, and she did just that.

Rose turned her whole body around, her senses heightened; she screamed "DUCK" and Jem did just that, his body falling to the ground in an unceremonious position whilst her arrow flew through the air, above his head and straight into the heart of the demon, leaving only ichor and a foul stench in its place. Rose looked around with slightly dizzy vision due to her injury and was thankful; they had killed all of the demons and had come out of everything safely.

She turned around in excitement to converse with Jem about their great efforts when she saw him still lying on the floor in the position he was when she screamed for him to move.

"Jem." Rose whispered, her voice slightly seeping out into the night. She quickly moved forward and was by his side in a mere few seconds, there was a stab wound in the side of his abdomen and blood was staining his previously clean black shirt. She ripped off her jacket, being quick with her movements and tightly wrapping it around his middle section, to put pressure on the wound and hopefully stop the vigorous blood loss. She whipped her stele out of her boot and drew an iratze on his arm as best as she could praying that it would help him.

"Jem, I-I need to get you help. I'm going to lift you up in a moment, just lean on me as much as you need. By the angel. It'll be ok." She tried to say reassuringly to his partly unconscious form, hoping her voice came out strong, but instead her words were as wobbly as his two feet on the ground. All Jem did was moan painfully in response to her trying to move him, she knew it hurt him but she had to get him back to the institute to get healed.

"I'm sorry Jem, just bear with me and when I pick you up, wrap your arms around me and hold on, if you can." She said quickly, picking up his seraph blade and sticking it in her belt.

She mustered up all of the strength she could and picked Jem up by the shoulders and hoped that she would be able to carry him on her back; it was a much better option than dragging him the four blocks it took to get back to the institute. With a deep breath she set off, trying to run as fast as her body would allow her too with Jem balancing on her shoulders, his arms around her neck and her arms wrapped around his legs, hoisting him up.

Eventually they arrived at the institute, but not that easily of course, Jem had slipped countless times, his arms flailing around his now unconscious body. She tried so hard not to cry and push on but the tears fell down as she carried him to the institute, his limp body barley hanging onto hers. As soon as they made it to the doorstep she screamed for help.

"HENRY. CHARLOTTE. ANYONE." Rose yelled throughout what seemed to be an empty institute, moments later she saw William run in, he must have just gotten back with Tessa and Cecily. As soon as he saw his parabatai's fragile state he ran over, quicker than she could recognise and picked him up off her shoulders. William rushed off carrying Jem in his arms towards the infirmary and shouting for someone to send a fire message to the silent brothers. Rose's vision became blurry and she couldn't tell if it was Charlotte or Tessa standing in front of her when she collapsed to the ground, her body finally giving out and shutting down and the last thing she remembered was muttering Jem's name, over and over before completely blacking out into a river of unsettling darkness.

Jem awoke first with a shaky breath. His eyes fluttered open, and he saw William sitting next to his bed, who was at Jem's side immediately, demanding how he felt and if he needed anything. Jem just shook his head, and relaxed into the pillows and soft blankets underneath him.

"What happened?" Jem asked William, his voice hoarse from all the sleep.

"You were injured on a mission with Rose, your wound was pretty bad, it was good that Rose got you here when she did." William relayed, and the words seeming to trigger something in Jem, making the events of the previous day flash through his mind in countless vivid images of the attack. Rose. His brain seemed to switch immediately to her. Where was she, was she okay.

"Where's R-" and William cut him off before he could continue by pointing to the other side of the room, about a metre away was another bed in the infirmary and laying on there was Rose, her face slightly paler than usual, her hair sprawled out underneath her.

"What happened to her?" Jem asked, trying to get up so he could move over there to see her, when the pain in his side increased more so than it had been when he was laying still.

"She saved you. She had a pretty nasty wound too, sliced half of her stomach area. She carried you on her back the whole way back here before collapsing… she's been out ever since and not responding very well to treatment." William said, straining his eyes in the other direction. Rose was a childhood friend of Cecily, and William practically treated her as family. Jem's heart clenched when William said that. He couldn't help but feel guilty, like this was his fault and that's why she was laying there in the bed, her usual charming smile wiped free from her beautiful face, replaced with a pale grimace instead.

"Is she going to be okay?" Jem whispered softly, turning his head to face William.

"I hope, Magnus is coming soon to help." William said, before leaving the room giving Jem and the unconscious Rose some space.

Jem sat up this time, biting the inside of his cheek when the pain exploded in his side, making him rethink his decision of going to sit next to Rose on the arm chair sitting next to her bed. He took in a deep breath before moving off the bed and limping towards the chair as his body cried out in pain. His breath hitched even more when he saw her, if he thought she looked sick from over there, well then she looked deathly here. He brought his long nimble fingers up, brushing the hair away from her face. He then moved his fingers gingerly down her neck, then her arms, tracing every part of her before holding her hands in his own. He brought her hand up to his mouth, kissing it and leaning it against his cheek.

"Why'd you have to go and be the hero rose." He whispered with a shaky laugh, staring at her unmoving form, which put him on edge even more. What if she didn't heal? What if she died, all because she saved his life?

"Rose. Please wake up." Jem said, running his thumb along the soft skin of her freckled cheek.

"Don't leave, not yet." Jem spoke in a brittle voice. He absentmindedly rubbed his thumb against the pale skin of her hand for the next few hours, just sitting next to her unconscious form. He nodded off later on, ending up leaning his head on the bed, his fingers intertwined with hers.

William came by an hour or so later carrying a tray with some tea and easily digestible food for Jem. William's heart was swelled when he saw his parabatai looking so drained and heartbroken over Rose. She had done the bravest thing a shadowhunter could do, she had done his job as Jem's parabatai and William owed her everything for saving Jem's life. William set down the steel tray over on Jem's side table and placed the lid over it, allowing the warmth to stay in. He wondered how long it would take til Magnus would arrive and be able to help Rose. William sighed and walked out of the room and down to the library in order to find out when Magnus would arrive, and just as he walked through the large wooden doors Magnus was there sitting in the couch and in a deep conversation with Charlotte and Henry. William cleared his throat, and his old friend made eye contact with him, though instead of the usual excited vibe, Magnus looked drained and on edge.

"Magnus, you've arrived. Shall we go upstairs now and see to Rose?" William inquired, as calmly as possible. He noticed that something was wrong. There was an unmistakably sense of fear setting within the room, most likely surrounding the treatment of Rose.

"William. I must tell you now that due to the extent of Rose's injuries, I may not even be able to help her. It's not just as simple as a flesh wound, she was poisoned, and healing her would come with great risks." Magnus warned as he walked down the hall leading to the infirmary along with William, Charlotte and Henry trailing behind the two. William stopped just before the door entrance to the infirmary where Rose lay in the bed, dying slowly. He turned to Magnus, a stern and intimidating look upon his gorgeous features.

"Magnus, Rose is practically family to me. She's saved my life countless times and she was there for Jem, my parabatai when I wasn't. She saved him. I owe her everything as does Jem." William said before pausing and then continuing on with his opinion. "There may be risks to this, but what's a greater risk than death itself?" William put out there, before trailing his blue eyes towards the hall and walking away, most likely to be in the calming company of his sister and beloved.

Magnus took a deep breath and walked into the infirmary and saw Jem sitting there with Rose. Jem was whispering calming words in mandarin, one's that Magnus picked up on. Magnus didn't even bother with acknowledging Jem through conversation; he didn't want to waste time. He stood at the end of the ruffled bed. The sheets were stained with multiple splotches of scarlet blood and it was hard to tell the difference between the white sheets and Rose's skin colour. Magnus started to mumble spell enchantments, his eyes glowing bright yellow as magic radiated off his hands and into her body, essentially trying to heal her. The spell he was using was the only one he knew would heal her. Though the side-effects did include partial paralysis from the waist down, though it wasn't permanent, probably would last longest up to three months.

Jem stepped back in awe as he witnessed the magic wrap around Rose's body like a blanket, cloaking her in the warmth of the colours of the rainbow. Colour started to show on Rose's skin, it returning to its usual soft cream colour, and a light pink staining her cheekbones, making her face look full again rather than deathly. Jem prayed to the angel that this would work and she would wake up.

Sluggishly her eyes flicked open and she felt safe. Her blue eyes immediately travelled to Jem who was by her side in seconds, making sure that she was okay. Magnus sighed relieved that she was awake; he left the room giving them time alone and went to alert the others of the success.

"Jem." Rose breathed out, relaxing finally knowing that he too was okay. The last thing she remembered before blacking out was literally dragging Jem out of that place on her back and to the institute; her body collapsing as soon as Jem was in William's arms.

"I thought you were going to die on me." Jem choked out, bringing her into a crushing hug.

"I could say the same thing about you." She chuckled, and then realised she shouldn't have; she felt the pain vibrate through her chest, and she grunted very un-lady-likely and leaned back on the pillows. Jem took her hand in his again, and this time she curled her fingers around his and squeezed his hand slightly, letting him know that she was alright.

"You saved my life." Jem began, before she interrupted.

"Is this the part where you thank me for my gallant efforts?" she joked, noticing the compassion and worry in his eyes.

"Don't you ever do it again." Jem said seriously, before hugging her again. She wrapped her arms around his neck and rubbed soothing circles on his back. "It's okay, I'm fine now." She whispered, wiping away the tears escaping his eyes.

"We're both safe now." She said, pulling back from the embrace and there was warmth in his eyes that she never noticed before. Jem moved his hand towards her cheek, tucking a strand of her hair behind her ear and caressed the side of her face as her eyes fell shut. Her body felt relaxed and she couldn't help but sigh in contentment when his soft lips touched her own a moment later. She relished and savoured every minute detail of kissing Jem and for the first time since she woke up, didn't feel any pain, but happiness. Jem pulled back, tears still slowly slipping down his cheek as hers were as well, though this time they were tears of relief and contentment with each other.

The rest of the day, they spent in each other's company in the infirmary, trying to rest but at the same time steal kisses from each other and mostly just stare at each other lovingly. By the end of the night when William came to check up on the two, he couldn't help but chuckle at the sight of the tangled blankets, toppled on top of the two, laying on one bed and Rose snuggling into Jem's sleeping form. William was happy that Jem and Rose were both alright and on their way to healing now, but he couldn't help but feel guilty remembering what Magnus had said. The side effects of this magic could lead health problems with Rose later on in her life, but the only other option was death, thinking about it more just made him feel worse, that's when he felt a hand on his shoulder. He turned around, his blue eyes meeting Tessa's.

"You made the right decision William in asking Magnus." Tessa said, knowing exactly what was on his mind. The two walked away from the infirmary and into his room. She pulled him into a hug and tried to reassure him.

"What if Magnus was right? What if it leads to something bad." William exclaimed, slouching down on his bed.

"She's alive for now, that's all that matters. If he didn't heal her, then she'd be dead." Tessa said, sitting down next to him on the edge of the bed.

"I know. I know." He mumbled.

"Then don't worry." She said, kissing his cheek.

"They did look happy while they slept." William mused, causing Tessa to laugh. Rose and Jem looked adorable and they were all glad the two were alright and together after so long. It was a nice ending to a horrible day.