A/N: This is my first attempt at FitzSimmons angst and I'm basically just really sorry. I'm working on something fluffy too by way of an apology. Please note that this story comes with a major trigger warning for a character death.

I obviously don't own AoS characters or the song by The Script. The song isn't based around the death of a love one, but I really felt it helped this story along, and if you don't know it I'd recommend having a listen while you read.

All thoughts on this are most welcome.

"And, you're a hundred percent sure about this, Agent Fitz?" Agent Weaver asked seriously, gazing at him intently from behind her hands, her long fingers domed together.

He'd never been surer of anything in his life but because his throat was sore and his eyes were threatening to let loose a tidal wave over his cheeks, he kept his reply as concise as possible.

"Yes, Agent Weaver, I am," he told her firmly, letting his tone infer that there was to be no reconsidering, no wavering and certainly no doubt surrounding his decision.

She gave a long sigh and appeared to consider her response.

"Far be it from me to try to force you to reconsider," she said, weighing each word before she spoke. "But I really would ask you to keep your options open," she suggested gently, but he shook his head immediately.

"No," he said softly. "I'm sorry Agent Weaver, I know it seems like a rash decision but it's something I need to do."

"Well, I won't pretend that this isn't something I regret immensely, but I do understand why you feel the need for a clean break," she conceded and scrawled her signature on a few documents. "I see you've already had Agent Coulson sign these, so you'll just have to wait for the Hub to send you a confirmation of severance, assuming they accept the application," she told him sadly and he nodded mutely. "I can send them off myself, if you'd like?"

"If it's not too much trouble, thank you."

"Not at all," she rose and he mirrored her, beginning to edge towards the door. "I hope, of course, to see you one more time before this all goes through," she said, looking at his face, a worried expression on her own.

"Of course, Agent Weaver, and thank you for being so understanding."

She opened the door and smiled sadly at him.

"I only wish I could have done more," she told him as he stepped into the corridor. "Take care of yourself, Agent Fitz. My door is always open," she murmured, and he gave her a smile, knowing it was probably completely hollow, and made his way through the familiar labyrinth that was the Academy's main office.

Walking along here without her just felt wrong. Walking anywhere without her by his side was alien to him by now. Even that last time, on that last mission, she had been beside him. Until she wasn't anymore.

They ran together, a few paces behind the rest but completely in step, as they always were.

Somehow though, the instant she wasn't there, he knew it. He'd turned and watched in muted horror as a Centipede soldier, no doubt acting on the instructions of someone higher up, had dragged her back into the lab they had just escaped. The one that was being consumed by flames. She'd tried to get free without success and, as she'd been about to disappear, she'd looked and up caught his eye. She knew instantly what he was about to do.

"Don't you dare!" she cried, but she must have been mad, thinking he wouldn't follow her.

He ignored Skye screaming his name, ducked Ward's outstretched arm and was back in the blazing heat, the flames roaring and consuming everything in their path, the smoke choking him and making his eyes burn.

Just thinking of the heat was enough to make him feel hot and panicked, even now. The thought of what he had left her to face alone made his heart rate quicken and his breath grow shallow as his mind raced with a hundred thoughts a second and his palms got clammy and it was all he could do to get out into the night air before the wave of anxiety broke over him.

He sat himself down on the grass and rode it all out. He'd barely had a single panic attack in all the years he'd known her but now they were back like an old friend and there was no one there anymore to hold his hand and help him through it.

Once it had subsided he got unsteadily to his feet, scuffing his shoes on the ground as he made his way to a familiar spot in the grounds of the Academy, a little corner of grass from which you could see almost all of the campus. It was the spot where he had first met Jemma. He'd been alone for his first month or so at SHIELD, had truly thought that he'd be able to make friends there with like-minded people but had only been more bitterly disillusioned when he had done nothing of the sort. She approached him one evening as the summer was beginning to draw to a close, as bold and bright as ever and even though she'd told him later that she'd been nervous, he never would have guessed at the time. She'd told him that she'd heard all about him, asked if they could talk, sitting beside him eagerly the moment he agreed. Rolling some blueprints out over knees she showed him a design she'd made, talking ten to the dozen about its biochemical elements but explaining bashfully that she wasn't much of an engineer and would be delighted if he'd maybe take a look. She'd left the designs with him, telling him she'd meet him there tomorrow.

When she was late the next day, he had thought it had all been some cruel joke to raise his hopes and then dash them, and he had been all set to leave when he saw her jogging over. She apologised for being late, but then drew two bottles of lemonade and some snacks from her bag, telling him cheerily I brought some supplies for us. Together their invention was one of the best ever produced by an Academy freshman and they'd been inseparable after those early days of planning and designing, even during the awkward, tentative stages of new friendship.

He couldn't begin to speculate how many summer days they'd spent there together after that. It wasn't a popular spot with many students, as it was too far removed from the Academy, and they were rarely interrupted as they talked about inventions and ideas, and pointed out constellations once night had fallen as they sipped tea from a flask or beer they'd snuck out of the confines of the Boiler Room.

His feet carried him there now as though he'd never been away and he thought perhaps once he got there he might find her waiting for him, already stretched out on the grass, and she'd ask him what had taken him so long and the last few months would all just melt away to nothing.

He didn't know how he knew which way they'd gone but he found himself gaining on them as he raced onwards, oblivious to the heat and the danger.

His heart had nearly jumped into his throat as the guard's foot had gone through the floor, his grip on Jemma had slackened and she jumped away on instinct as the guard immediately went tumbling out of sight. His screams barely echoed over the sound of Fitz's heart beating in his ears and he barely registered the eventual thud as he finally hit the ground. But Jemma was still there, she hadn't fallen. He could still do this. He hadn't taken the plunge to save her last time, but this time would be different. It had to be.

The guard's fall, however, had brought substantial parts of the floor down with him and it was only the fact that Fitz had been so far behind them that meant he was still alive. He watched as the whole floor seemed to fall away in slow motion, leaving a chasm between them that had to be over ten feet wide.

Dread filled him like a leaden weight as he realised that there was no way either of them was going to be able to make the jump from one side to the other and that there was no escape route on Jemma's side, everything a blazing wall of flames. He gazed around for something to help him work out a solution, coughing as smoke hit the back of his throat and ash obscured his vision.

"Fitz!" she shouted and he looked up. What brilliant, fantastic idea had she had? "Get out!" she demanded, voice high and tears in her eyes as she tried to make herself as small as possible.

What?

"Are you crazy?! I'm not going anywhere!" he replied, struggling to make himself heard.

"Yes you bloody well are! I want you to leave while you can still get out!"

"No! I'm not going without you! There's got to be a way to get you over here!" He began casting about desperately for some kind of answer. "I just need a moment to figure something out!"

"Fitz for God's sake there's no solution to this! I'm stuck and you're not and I need you to go while you still can. Sometimes there just isn't an answer Fitz!" she cried helplessly, anticipating his reply, and since when had Jemma stopped believing that everything could be solved with a little bit of thought?

"There has to be!"

"But there isn't," she shouted. "Please!" she half-shrieked, all semblance of self-control now gone. "I needyou to go Leo. I can't watch you die for nothing."

For nothing? What was she talking about? He couldn't leave her. He couldn't just turn around and walk away like that. What kind of person would that make him? Christ he'd rather die in here with her.

"Leo! Please, for me. If for nothing else just please go for me. For God's sake just get yourself out!" she was sobbing now, her eyes frantic as she watched something behind him. He couldn't care less what it was.

"Jemma I – " but he didn't know what to say. There were a million things he wanted to say, an endless number of things that he wished she could know, but she was crying and begging him to go and telling him he was her best friend and she couldn't let him die because of her, and hell this had to be a nightmare, or if not then was it surely the end of the world.

Then suddenly she was begging someone else to make him leave and there were two strong arms around him and Ward's voice in his ear telling him he was sorry over and over and he was being dragged away and the last thing he'd ever remember of her was the way she collapsed to the ground, arms around herself as she watched Ward pull him away, determined to know that Fitz would make it out alive even knowing that she would not.

Sometimes, he thought about what he'd have told her if he'd had the chance. But usually, he just thought about what he'd never said, or done. He'd never told her how beautiful she was, he'd never let her know just how much he loved her. They'd been on the precipice of something new, of a change in their relationship and he'd just allowed himself to dream of a future filled with wedding vows and curly-haired children and a house in the countryside.

He remembered like yesterday the way they had finally taken the plunge and spoken about their feelings, the way they had sat side-by-side on this bed and been frank and honest. Or, she had been. He'd been too scared he'd muck it up and say the wrong thing and so he'd just kissed her, and she had drawn him close and kissed him back and they'd suddenly found themselves tangled together on his bed in a flurry of sighs and moans.

They'd been pulled away to brief for their mission, the new something killed before it could even get started.

Fitz would never forget how his knees buckled when he saw her after. He'd seen death a hundred times working in the lab with her, had smelt death, had known how it sunk people's faces in and mottled their skin. He knew it was natural, she'd told him a million times.

But the sight that had met him wasn't natural, how could it be? Jemma smiled constantly and she moved her hands when she talked and she raised her eyebrows impossibly high when she was excited. How could it be natural that she was lying there completely still, hands resting on the thin sheet that covered most of her body. They were pink and blistered and the burns seemed to be everywhere but her face itself, deep, angry blisters in the skin of her arms, her shoulders, her chest. She had died like that, in pain. Jemma. His Jemma.

The books and movies had lied, she didn't look like she was sleeping at all.

He'd burst out of the room as quickly as he'd entered it, pushing past a tense-looking Ward and ignoring the sight of Skye sobbing into May's shoulder as they sat on stiff-looking chairs. How he got outside he didn't know, but he found himself kneeling at the side of the building, heaving up what little was in his empty stomach and shivering as he broke out in an icy sweat.

All of the team but Skye had volunteered to identify her body so he didn't have to, but he had refused. He had thought that maybe if he saw her he'd believe it, because it didn't feel real that she was gone. And it didn't matter what he had seen, what effect it had had on him. He couldn't wrap his head around the idea that she was gone, even as he eventually calmly returned to the viewing room, asked to see her again. This time he didn't run away, but held her hand and stroked her cheek and told her over and over that he was sorry until Coulson had come in and gently pulled him away, murmuring to him words that sounded like 'that's enough now Fitz, come on son,' but he couldn't be sure because he couldn't hear over someone's dry, wracking sobs. It only occurred to him later that they had been his own.

Even now, if he were honest, he'd convinced himself that she was still alive.

At first, simply to cope with the crushing weight of it all, he had told himself that she'd taken off somewhere and that she'd come back if only he waited long enough. And then the idea stuck, it grew roots and a few months later with his constant nurturing it had flowered. He had taken to playing stupid games with himself, had convinced himself that if he could only count all the seconds in an hour without missing one, if he could disassemble and service a machine in a certain time, or if he recite could the entire periodic table correctly then he could bring her back to life. He knew how stupid it was, but he couldn't stop.

Sometimes he forgot himself and referred to her in the present tense, or otherwise made clear the little game he was playing with himself and the worried, pitying looks he received made him feel sick to his stomach. Even knowing that this was all because people cared about him didn't make a difference. His mother called him constantly, begging him to come home for a while and it was all he could do not to snap at her and hang up the call, and for weeks he'd noticed that he almost always had a chaperone in the form of a team member. Skye would join him in the lab when all he wanted was to be alone there and to feel Jemma's presence in the room's very walls, but was too scared to hurt Skye's feelings by telling her to get out. Ward had taken to sitting in the common area whenever Fitz did and May or Coulson would often bring a little of what they cooked to his room because he frequently forgot to eat or often he simply felt simultaneously too empty without her and too full of the longing to have her back to even want to consider adding food to the nausea-inducing equation.

So worried was Coulson, that when Fitz told him he wanted to leave, he had initially refused his request. It occurred to Fitz that Coulson would rather have him on the Bus, utterly useless in the lab and not even stable enough to go out on missions, than send him back off into the world because at least on the Bus someone was there to keep an eye on him. But Fitz had been insistent. He had to go. The field had always been her dream, not his and when he thought about SHIELD at all, he thought of her. He would have left whether Coulson had signed the damn papers or not.

And now as he waited out his remaining time at the Academy, he wondered if he sat here on this grassy corner forever, maybe she'd come and find him. And if that was all it would take, an eternity in the rain and sun and snow in the place where some of his happiest moments had taken place, then he would do it without a second thought.

He had a fleeting vision of becoming a local news story as he waited. Of people trying to move him on and of news crews interviewing the man who wouldn't be moved. Maybe, wherever she was, she'd see the news reports and come and find him.

She was buried in a normal, non-descript cemetery in her local town and it seemed like half the people who lived there had known her in one capacity or another. It was little comfort, but SHIELD had paid for everything.

Her parents and the eldest of her younger sisters had cried solidly during the service and had barely been able to stand as the coffin was lowered into the ground. It was her youngest sister, barely even a teenager, who bit her lip and squared her shoulders and refused to let herself break down. As he didn't bother to wipe away his own tears, he admired her strength and was reminded painfully of his beautiful, resilient best friend. Ellie had always been older than her years, and had doted upon Jemma like no one else. Bright and inquisitive, she had sought out her sister's opinion on almost everything. He wondered who she would ask now when she wanted a genuine opinion on how in scale her drawings and sketches were.

And all around were murmurs that this should never have happened to someone so young.

He stood and sat alone throughout the funeral, and was glad to keep to himself. Barely anyone had known him, these were all people from her past life, from her life before SHIELD, and the Simmons family was too wrapped up in their own grief to offer any comfort to the Scottish boy whose suit was a size too big.

He had promised her mother that he would always protect her, had assured her that he'd bring her home. But he'd never meant for it to be like this. He didn't deserve their support, didn't want it.

"Who's there?" came a sudden voice and he hastily wiped his cheeks dry, looking around and finding a janitor making his way across the grounds, ready to clean up a day's worth of mess and rubbish from the Academy.

"Sorry," he mumbled, introducing himself and handing over his badge.

A strange look passed across the older man's face, but Fitz supposed everyone knew who he was by now, and no longer because he was one of the two smartest Academy graduates. The only one, now.

Jemma's name had gone up on the Wall of Valour and the story had been told a million times and probably wildly exaggerated by now. Everywhere he went, not that he often left the room the Academy had temporarily put him up in, people would suddenly stop talking and stare. A few offered him condolences, but mostly they didn't know what to say. Even in that first, friendless month at the Academy, he hadn't been as alone as this and that solitude marked him out more than his intelligence ever would. His posture was more hunched and he looked at his shoes whenever he walked anywhere because looking up only reminded him that he walked alone.

"You know you can't really be here at this time?" the caretaker told him gently and Fitz half-nodded.

"I'm sorry, it's just…I'm waiting for someone," he said, his voice cracking and his throat sore and he looked away because the man nodded and walked off with that look of pity on his face and he thought he might tear his own hair out if he saw that look one more time.

He knew what it was to feel sorry for him. He did it enough for himself, lying awake at night begging for a sleep that wouldn't come as his mind replayed images of how he imagined her last moments would have been spent. And when the insomnia got too much and he lost the last of his self-control he would punch his fist into his pillow and wish pathetically that she was still alive, or that the fire had taken him instead because if this was the pain he would have to bear for the rest of his life then it was not worth the sad, empty future he envisaged. It was not until she was gone that he realised that every scenario he had mapped out for himself, for his future, involved her too.

Now what could he do? What was he good for without her? He wished again that he could sit there forever, just waiting for her to remember him and realise that she missed him like he missed her and start searching for him. Because this spot here, their little corner of happiness, would surely be the first place she would look, so how could he risk leaving? People might try and make him leave, sure but stubbornness was built into his very being, fused to his bones.

He stretched his legs out and looked at his feet, tapping the toes of his battered trainers together absently.

If that was what it took then that was what he would do, he'd be the man who can't be moved.