AN: So the lovely blanania on tumblr has given me permission to write a fic about her wonderful Gajeel/Levy humanoid-robot!AU, and this is the result! This will be a fic in two parts, and I'm coordinating my writing with Grace's illustrations so you should all check them out first.

The setting is this: "Centuries into the future, when humanoids are used for many purposes, including war, Kurogane – a warrior humanoid from Phantom Lord – lost a fight and was abandoned, buried in layers of snow and ready to rust. However, Levy McGarden – a humanoid professor and mechanic working for Fairy Tail Inc. – found him and named him "Gajeel". A new life for Gajeel began, but also new dangers as the former army are coming for him and his saviour."

Disclaimer: Fairy Tail and its characters belong to Hiro Mashima; I own absolutely nothing. This AU idea and the artwork this story is based on, as well as the cover image, belongs to Grace (tumblr's blanania); I'm just playing around in her sandbox.

Wrought Iron Heart

by Miss Mungoe

part 1: saviour

Gajeel knew war.

He knew it in the marrow of his artificial bones – knew it like an organic being knew how to move and laugh and breathe. It resonated in every metal-wrought arch and joint, like the sing of blood in coils like veins – the very essence of his being. He'd been created by it, moulded by it, and he'd lived by it. As much as a humanoid could really live, anyway.

Then she'd dug him out of that snow bank, and living had been given a whole new meaning. It was her calloused mechanic's hands that had put him back together, and her laughter was a command unlike any he'd ever known, not ordering but compelling him to mimic the quirk of her expressive mouth. Hers was the will that had brought him back from the brink, and hers the kindness that had seen more in his empty shell than a machine whose sole purpose was war and mindless destruction. His Creator had given him a form, a drive and a purpose in the form of warfare, but the mechanic – Levy – had given him life.

And for her sake, he'd give it up in a beat of his mechanical heart.

"If we keep going down this way, we'll be backing ourselves into a corner – there's no way out." Levy ran a hand through her hair as she paced, but the cramped space of the corridor granted little room for her anxious steps. She'd lost her tool belt somewhere along the way and her hands twitched at her sides, restless without a weapon to hold. She wasn't a fighter to begin with, but even a mechanic would feel empty-handed going up against a group of enemy mechs the size of the one hot on their trail.

"She's right," Lily agreed, calm as always, but Gajeel could pick out the erratic leap of his pulse, and the rigid lines of his flesh shoulder that betrayed his composed demeanour. "And if we linger here, they'll catch up."

Gajeel rifled through his memory for ideas, but found instead a rather impressive dictionary of cuss words. He didn't feel panic – he wasn't programmed to, and for all the adjustments shortstack had made she hadn't tampered with that. But though he didn't feel it, that didn't mean he didn't understand the severity of the situation. If he'd still had his old combat function, he could have cut his way through the solid concrete walls boxing them in, or even taken on the group heading towards them, but he had none of his old weapons, and they couldn't take on a small army of enemy mechs bare-handed.

Regret, too, was a feeling he hadn't been programmed to recognize, but he could not stop thinking about what would have happened if they hadn't left for the dig in the first place – if they'd just stayed in Magnolia, cooped up in Levy's workshop. But the logical part of his mind pointed out that there was no way they could have known there would be an army of Phantom Lord humanoids waiting for them at the dig site. The abandoned mech factory had suddenly swarmed with Phantoms, but they'd managed to escape, although by the looks of things they'd been successfully herded into a trap; there was no breaking through the walls by any means they had at their disposal.

Levy looked at him then, eyes wide and pleading for a plan he didn't have, and he was reminded of the first time he'd seen her, though her eyes had been full of excitement then, on a day her dig had been successful, and death hadn't been hot on their heels.

"Gajeel?" There was a tremble in her voice, one he wasn't used to, and he'd heard and catalogued every pitch and lilt from the moment he'd first heard it.

"...this wire..."

"...if I attach it...the power circuit..."

He registered the touch – the warmth of human hands, a persistent tug at his circuitry that sent a jolt through his system and his eyes flew open–

"Holy sh–"

"Levy, get back!"

His vision was shrouded in darkness, and whatever had woken him was out of his line of sight, although he could pick out their heat signatures, and feel their movements on the air. Three people, by his estimation, though he didn't fully trust how operational his system was. From the temperature they were inside somewhere – the echo indicated a cramped space, sound-proofed walls, cement floors. But his eyes, though open, were unseeing.

"Wait – no, wait, Jet, let me just–"

Something connected, he could feel the jolt, and then there was light – light and something very bright and very blue, and when his vision adjusted he could make out a pair of wide, curious eyes – human eyes not humanoid, living and vivid and bright with life not the cold unsympathetic gaze of the enemy looking down the glare of a blaster ray–

"Hello?"

A warm palm against the side of his face and he couldn't move, rooted to his seat by something other than the power cables attached to his interface, but there was no fear in her eyes, only curiosity, and excitement brimming along the edges. He vaguely made note of two shapes lingering at her back, unease vivid in their rigid stances, but he couldn't draw his gaze from the human girl crouched before him.

"Can you understand me?" she asked then. "Do you understand Common?"

Kurogane nodded, the command racing easily through his system. They must have fixed him, because the last thing he remembered before waking up was not being able to move.

Eager pleasure lit up over her face at his sign of understanding. "We dug you out of a snow bank – you were frozen, but you're all thawed now and I did some work on your circuitry and your coils, and I removed and fixed some functions, replaced them with new ones–oh, I'm so sorry! My name is Levy. Levy McGarden, I'm a mechanic, you see, and we found you on a dig. What's your name?"

Her enthusiastic speech had left her cheeks flushed, but her eyes glittered and she was so close he could feel the heat from her hands. But her words left him baffled. "Name?"

She frowned. "Yes, your name. What are you called?"

He realized what she was asking for, but didn't point out that names were for humans – his kind were only given numbers, or titles if they pleased their Creator.

"Kurogane," he said then, after a pause, and watched as her brows furrowed.

"That's...not much of a name."

"Humanoids aren't given names."

Her frown deepened at that. "Maybe not where you're from, but ours are."

He glanced around him then, wondering for the first time where he was, and who she worked for. The facilities were too nice for her to be a freelancer, unless she was rich. "Ours?" he said instead, as he looked back at her.

She grinned. "Fairy Tail Inc. You must have heard of us – I recognized your...signature." She fumbled over the words, and he wondered at her wince. She should have just called it what it was – his Creator's mark, the claim of ownership. "You were part of Phantom Lord."

He wanted to point out that 'part of' was a bit of a stretch, and that it was closer to 'belonged to', but she was operating with a whole new set of terms he wasn't familiar with, and it threw him off. She'd said their humanoids had names, for one, although considering who she worked for, that probably wasn't much of a surprise.

"Fairy Tail?" He knew the name, of course – everyone did, humanoid or not. A soft bunch, the rumours went. They treated their mechs like partners and not like weapons. It was ridiculous, and bordering on insulting. He certainly wasn't human.

She nodded. "We're a bit...different. I hope that's not a problem?"

There was a sarcastic remark at the back of his mind – a particular idiosyncrasy he'd picked up from his former owner. Did she just insinuate he had a choice, even if he objected? She'd reprogrammed him, he could feel it – like a missing lib, she'd deactivated his combat function. He was a shell now, useless in battle. A glorified, massive metal paperweight. Or a hatstand if she so pleased. And if she was a mechanic worth her salt, she'd had a function built in to shut him down in a heartbeat if he so much as lifted a hand against her.

"No, 's no problem."

She beamed, happily ignorant of his inability to protest even if he'd wanted to. But she didn't seem a bad sort, and being a hatstand was probably better than being buried beneath the snow, anyway.

"Great!"

Then she grabbed hold of his hand, cheerfully ignoring his entire body jerking in surprise as she pulled it towards her. There was a pen in her other hand – the kind used to engrave a Creator's signature on their creations, but she didn't do that. Instead she scribbled something else across the back of his hand.

"Kurogane doesn't suit you," she explained, eyes focused so intently on what she was writing. "Let's call you 'Gajeel'."

"Gajeel?"

She nodded, and drew back to admire her handiwork with a pleased smile. When he pulled his hand back, he lifted it to look at what she'd written. And sure enough, there it was, in neat letters across the metal.

"Not gonna put your own signature?" he asked, glancing back up, only to find her smiling still.

"It's not mine to give," she said with a shrug of her shoulders. "We don't claim ownership here. But we do offer partnership."

Then she held out her hand, tiny and smeared with oil, with grime under her blunt fingernails. He stared at it, uncomprehending, and when he looked up to meet her gaze there was a question there, like she genuinely believed he did have a choice in the matter.

"Will you be my partner, Gajeel?"

"Gajeel?"

He looked at them then, the both of them – odd companions who'd made space for themselves in his mind and his memory, who'd given him a name and a place in their own, quite despite the fact that he wasn't of their kind. An old ragged army commander, half man and half machine, and a mechanic with enough affection in her reckless human heart to give life to a humanoid weapon. They were everything in his meagre existence, and looking at them, their fragile human lives teetering on the edge and with the enemy just around the corner, Gajeel knew what to do.

He looked at Lily then. "Take her."

The old commander's frown deepened, but he didn't waste time arguing, though Gajeel didn't doubt he wanted to. Instead he simply nodded, and without a word went to pick up the mechanic. "Wh– Lily what are you doing–" she squeaked as he hoisted her up, but didn't offer any protests, only wiggled around in his grip until she could meet Gajeel's eyes. Confusion was evident in the furrow between her brows, and he wondered suddenly if she'd ever forgive him for what he was about to do.

"Gajeel? What's going on?"

Gajeel didn't drop her gaze. "The wall is thick, but it's not impenetrable. A good explosion should make a hole big enough for an escape."

She rolled her eyes at that. "I know, but we don't have any explosives or we would have–" she stopped herself, and he watched the confusion melt away to understanding.

And then horror. "No–!"

Lily held her in place as she thrashed, clawing at his arms and kicking her legs, but she'd always been such a small thing and her resistance made little difference. "You can't–you said you wouldn't go back to being a weapon! You–"

"I'm not."

He smiled then – made his artificial muscles obey the memory of her patient tutoring, the fond roll of her eyes as she'd explained the human practice of showing humour and contentment, the curve and quirk of a mouth that could mean so many different things. And she'd showed him even when she hadn't been actively teaching him – fond smiles and excited ones reserved for brand new pieces of mech she could take apart; patient smiles and smiles reserved only for him. He'd catalogued them all, and aside from the colour of her eyes it was the one predominant memory he had of her, stored away where war and battle had once taken up so much space in his mind.

The breath went out of her. "You– you're smiling."

He shrugged – another gesture he'd picked up, but this mostly from Lily, who did an excessive amount of it in defence of his gossipmongering and general meddling nature. "I'm not a weapon," he said then. "Not anymore."

She shook her head, ready to protest, but he held up a hand to halt the words on her tongue. His gaze lingered a moment at the name she'd carved into the metal, and the one he'd engraved himself beneath it. Her name, like a Creator's signature, but different. He was hers, but by his own decision. He hadn't showed it to her yet, but there wasn't any time for that now.

"This ain't an action that's been programmed into me," he said then, hoping she'd understand. "It's a choice. You told me to make my own decisions, that that's why you reprogrammed me."

His changed the curve of his mouth – a smirk she'd called that, and her textbook definition had been 'the kind of smile that follows a wry comment, or suggests self-satisfaction or smugness'. It wasn't a very self-satisfied moment, but had the setting been different he imagined he could have felt a little smug at his own reasoning. It went to show how much she'd taught him.

Sounds of the approaching humanoids from Phantom Lord broke the stunned silence that had settled between them, and Gajeel nodded at Lily, a silent order, but despite his assurance she called after him to stop, come back don't leave me don't you dare leave me don't you dare–

Her voice grew faint as he put distance between them, enough to make them clear of the blast radius. He'd always known about the inner explosive mechanism – the kind built into all Phantom Lord units to ensure their secrets died with their humanoids, to keep the enemy from gathering the parts and the memory discs. There'd be no putting him back together after this, Gajeel knew – knew it like a truth embedded deep into his circuitry. It was designed specifically to destroy the part of him that made him operational, and the part that made him who he was. If humanoids had souls, or their equivalent of, triggering the explosive would eradicate it.

The steady thrum of the approaching group of mechs shuddered through him, a steady drum drum drum of drones against the hard ground underfoot, but he drew his attention away from it, letting his mind focus on the thought of her – the concentrated wrinkle between her brows as she worked on her projects, and the sound of her laughter loud like a bell and shrieking when he hoisted her up unexpectedly to help her reach the top shelves in her workshop. He let his mind settle on that sound, to drown out the desperate calls for him to come back don't leave, as his hands skimmed over the wall. The blast would do it – it would have to; they had no other escape. Lily would get her to safety, he knew, but this – this was his job. Gajeel's job, not Kurogane's. He'd left the title behind, and he was taking the new one to whatever afterlife awaited his kind.

Sorry, Shorty.

The mechanism was activated with a thought, and then all he could see was light. Light, blinding, burning, searing, scorching light. And in his mind as it tore apart, the blue of her hair and the endless dark of her grinning eyes.

AN: Make sure you all check out Grace's art! Part 2 will be posted in correspondence with her next round of illustrations, so stay tuned.