Aaron

The days passed in a blur of training and preparation for the upcoming expedition. The old castle that served as the Survey Corps' base was a hive of activity, soldiers bustling about with a sense of purpose that bordered on frenetic. Amidst this controlled chaos, Aaron Mustang's squad found themselves engaged in the more mundane tasks of maintaining their equipment and the castle grounds.

On a particularly crisp autumn morning, the courtyard was alive with the sounds of work and the occasional grumble of complaint. Aaron stood near the stables, his attention focused on the magnificent black stallion before him. His hands moved in practiced motions as he brushed the horse's coat, the repetitive action almost meditative in its familiarity.

Nearby, Jean Kirstein was engaged in a far less pleasant task. Armed with a shovel and a wheelbarrow, he was tasked with cleaning up the horse droppings that littered the courtyard. His face was set in a perpetual scowl, muttered curses punctuating each scoop of manure.

"This is ridiculous," Jean grumbled, loud enough for Aaron to hear. "I didn't join the Survey Corps to shovel shit."

Aaron glanced up from his grooming, a smirk playing at the corners of his mouth. "Come now, Kirstein," he called out, his voice laced with mock sympathy. "With that long face of yours, I thought you'd feel right at home among the horses."

Jean's scowl deepened, his grip on the shovel tightening. "You bas-" he began, before catching himself. Instead, he settled for a string of muffled insults, just loud enough for Aaron to hear but not quite clear enough to warrant punishment.

Across the courtyard, Gus and Dino were occupied with cleaning and oiling the squad's saddles. Gus nudged Dino, nodding towards Jean. "Would you look at that," he whispered, a note of awe in his voice. "The rookie's got guts, talking back to the Captain like that."

Dino snorted, shaking his head. "If that was one of us, we'd be running laps until our legs fell off," he replied, his voice equally low. "The Captain's going soft in his old age."

Their conversation was interrupted by the arrival of Nanaba. She approached Aaron with purpose, a steaming metal mug held carefully in her hands. The rich aroma of freshly brewed coffee wafted through the air, drawing appreciative glances from the other squad members.

"Here you go, Captain," Nanaba said, offering the mug to Aaron. "I thought you might need this."

Aaron's face lit up at the sight of the coffee. He set down his brush, accepting the mug with a grateful nod. "Nanaba, you're a lifesaver," he said, taking a long sip. "This is exactly what I needed. Thanks for always being so thoughtful."

Nanaba's cheeks colored slightly at the praise, a small smile tugging at her lips. "It's my pleasure, Captain," she replied, her voice warm.

From her position near the edge of the courtyard, where she was busy sweeping fallen leaves, Christa couldn't help but notice the interaction. A small frown creased her brow as she watched Aaron and Nanaba chatting amiably over the steaming mug of coffee.

Gus, ever observant, caught Christa's expression. He leaned towards her, his voice low and teasing. "Better watch out, little rookie," he said with a wink. "Looks like Nanaba's trying to steal your Captain away."

Christa's face flushed a deep red, her hands tightening on the broom handle. "I-It's not like that," she stammered. "The Captain and I are just friends."

Before Gus could respond, Jean's voice cut through the courtyard. "Oi, Mustang!"

Aaron lowered his coffee mug, fixing Jean with a stern look. "That's Captain Mustang to you, Kirstein," he corrected, his tone leaving no room for argument.

Jean's face contorted into a forced smile, the effect more grimace than grin. "Right, Captain Mustang," he said, the words dripping with sarcasm. "What's the plan for tomorrow? More shit shoveling, or are we actually going to do some real training?"

Aaron took another long sip of his coffee before answering, his expression unreadable. "No idea," he said finally, his tone nonchalant. "And frankly, I don't care."

Jean's forced smile faltered, replaced by a look of confusion. "What do you mean?"

"My vacation starts tomorrow," Aaron explained, a hint of satisfaction in his voice. "Nanaba will be in charge of the squad while I'm gone."

Jean's jaw dropped in disbelief. "But the expedition is right around the corner!" he protested. "How can you just take off now?"

Aaron shrugged, seemingly unperturbed by Jean's outburst. "Turns out I won't be needed on this one," he said, taking another sip of coffee. "So I might as well take some time off."

"Unbelievable," Jean muttered, shaking his head. "You're nothing but a lazy good-for-nothing."

Aaron's only response was another nonchalant shrug. "Think what you want, Kirstein. Now get back to work. Those horse apples aren't going to shovel themselves."

As Jean grudgingly returned to his task, Nanaba stepped closer to Aaron. "How's the coffee, Captain?" she asked, a note of hopefulness in her voice.

Aaron's face softened as he turned to her. "Delicious as always, Nanaba," he said warmly. "You know I've always loved your coffee."

From her position across the courtyard, Christa couldn't help but overhear the exchange. She felt an unexpected twinge in her chest at Aaron's words, her grip on the broom tightening unconsciously.

Dino, noticing Christa's reaction, leaned in with a conspiratorial whisper. "Looks like the competition's going to be fierce," he teased. "Better step up your game, rookie."

Christa shook her head vigorously, her cheeks burning. "It's not like that," she insisted, though her voice lacked conviction. "There's no competition. The Captain and I are just... just..."

But as she watched Aaron and Nanaba chatting easily, sharing smiles over the steaming mug of coffee, Christa found herself unable to finish the sentence. Instead, she threw herself back into her sweeping with renewed vigor, trying to ignore the confusing mix of emotions swirling in her chest.

---

The next morning dawned clear and crisp, the first hints of sunlight just beginning to peek over the horizon. In the quiet stillness of the early hour, Christa found herself wide awake, her mind refusing to let her rest. The image of Nanaba handing Aaron that cup of coffee played on repeat in her mind, each replay sending a fresh wave of... something... through her.

With a frustrated sigh, Christa pushed herself out of bed. If sleep was going to elude her, she might as well make use of the early hour. She padded quietly through the silent hallways of the castle, making her way towards the kitchen.

The kitchen was dark and quiet, the only sound the soft scuff of Christa's feet against the stone floor. She moved with purpose, gathering ingredients and utensils with a determined air. If Nanaba could win Aaron over with coffee, then Christa would... well, she wasn't entirely sure what she was doing, but she knew she had to do something.

As she began chopping vegetables, the rhythmic sound of knife against cutting board filling the kitchen, Christa tried to sort through her jumbled thoughts. Why did it bother her so much to see Aaron and Nanaba together? They were comrades, friends even. It was natural for them to be close. And yet...

Her musings were interrupted by the sound of footsteps approaching. Christa tensed, her knife pausing mid-chop as she waited to see who would appear.

"Christa?" Ymir's familiar voice called out, tinged with surprise and a hint of suspicion. "What are you doing up so early?"

Christa relaxed slightly at the sound of her friend's voice, though a hint of guilt colored her reply. "Oh, Ymir. I'm just... making a light breakfast."

Ymir's eyes narrowed as she took in the array of ingredients spread across the counter. Her gaze lingered on the pile of chopped vegetables – far more than Christa would normally eat, especially given her known dislike for most greens.

"A light breakfast, huh?" Ymir said, her tone making it clear she wasn't buying it. "You hate vegetables. Who's all this really for?"

Christa felt heat rise to her cheeks, her hands fidgeting with the hem of her shirt. "It's... it's for Aaron," she admitted softly, unable to meet Ymir's gaze.

Ymir's expression darkened, a mix of concern and frustration crossing her features. "Christa," she said, her voice uncharacteristically gentle, "that guy is nothing but trouble. You know that, right?"

Christa's head snapped up, a flash of defiance in her blue eyes. "That's not true," she insisted. "Aaron is kind and always puts others first. He's a good person, Ymir."

Ymir's eyebrows shot up in surprise at Christa's vehement defense. "Oh? Is that so?" she said, her voice dripping with sarcasm. "Well, good luck with that then."

As Ymir turned to leave, her shoulders tense with barely suppressed anger, Christa called out after her. "I hope so," she said softly, more to herself than to Ymir.

The sound of Ymir's retreating footsteps echoed through the kitchen, leaving Christa alone once more. She let out a heavy sigh, her earlier determination wavering in the face of Ymir's disapproval.

But as she looked down at the half-prepared breakfast, Christa felt a renewed sense of purpose. Maybe Ymir was right, maybe this was a foolish endeavor. But Christa had seen a side of Aaron that others seemed to miss – the gentleness beneath his gruff exterior, the selflessness hidden behind his apparent nonchalance.

Christa's heart pounded in her chest as she ascended the winding stone staircase, the tray of carefully prepared breakfast balanced precariously in her hands. Each step seemed to echo loudly in the early morning quiet, matching the rhythm of her racing thoughts.

As she climbed, Christa found her mind wandering to Aaron. Despite his reputation for laziness, she knew there was more to him than met the eye. Few people realized just how integral Aaron was to the day-to-day operations of the Survey Corps. While others saw only his apparent nonchalance, Christa had glimpsed the dedication that drove him to work tirelessly behind the scenes.

She knew that at this hour, Aaron was likely already hard at work. The administrative tasks that kept the Survey Corps running smoothly often fell to him – drafting reports, correcting his comrades' paperwork, managing inventories, and strategic planning. Captain Levi might call him a slacker, but even he couldn't deny Aaron's invaluable contributions.

As Christa reached the landing where Aaron's office was located, she took a moment to collect herself. She adjusted her grip on the tray, took a deep breath, and approached the heavy wooden door. Without hesitation, she pushed it open, forgoing the customary knock. Aaron had mentioned more than once how much he hated the sound of knocking, preferring people to simply enter.

The scene that greeted her as she stepped into the office, however, was far from the quiet, industrious atmosphere she had expected. Instead, she walked into a maelstrom of raised voices and palpable tension.

"DON'T SCREW WITH ME, ERWIN!" Aaron's voice boomed, his face flushed with anger as he glared at the imposing figure of Commander Erwin Smith. "WE HAD AN AGREEMENT ABOUT MY VACATION!"

Erwin stood his ground, his calm demeanor a stark contrast to Aaron's fury. "I understand, Aaron, but circumstances have changed. We need you for this expedition."

Aaron's hands clenched into fists at his sides, his whole body radiating frustration. "Fine, I get it. No vacation. But I need tomorrow off. It's Rosy's birthday, and I promised I'd be there."

Erwin's expression softened slightly at the mention of Aaron's sister, but his voice remained firm. "I know, Aaron, and I'm sorry. But it's crucial that you're here for these final days before the expedition."

"No," Aaron's voice dropped to a dangerous growl. "Rosy is more important."

From his position leaning against the wall, Captain Levi spoke up, his tone sharp and challenging. "So you're saying your sister's birthday is more important than humanity?"

Aaron's head snapped towards Levi, his green eyes blazing. "YES! I'VE SAID IT BEFORE AND I'LL SAY IT AGAIN – IF I HAD TO SACRIFICE ALL OF HUMANITY FOR ROSY, I'D DO IT IN A HEARTBEAT!"

A heavy silence fell over the room following Aaron's declaration. Erwin's brow furrowed as he regarded Aaron with a mixture of concern and calculation. "Even knowing that Christa is part of that humanity?" he asked quietly.

For a fraction of a second, Aaron hesitated. His eyes flickered with an emotion Christa couldn't quite identify before his face hardened once more. "YES, I'D SACRIFICE HER TOO, WITHOUT HESITATION!"

Christa felt as though she'd been struck. The breakfast tray suddenly felt impossibly heavy in her hands as she struggled to process Aaron's words.

Erwin sighed heavily, pinching the bridge of his nose. "Aaron, I didn't want to tell you this yet, but I've been seriously considering you as the next commander of the Survey Corps. My successor."

Aaron's laugh was harsh and bitter. "I don't care. I won't be here tomorrow. In fact, I'll be gone for several days. If you want to expel me, go ahead. The other military branches are dying to have me in their ranks."

With that, Aaron spun on his heel and stormed towards the door. As he yanked it open, his eyes met Christa's. For a moment, surprise flickered across his face, quickly replaced by a mask of indifference. Without a word, he brushed past her and disappeared down the hallway.

Christa stood frozen in the doorway, the breakfast tray trembling slightly in her grasp. She felt numb, Aaron's words echoing in her mind.

Erwin's voice, gentler now, broke through her daze. "Did you hear all of that, Christa?"

She nodded mutely, unable to find her voice.

Erwin's blue eyes were filled with sympathy as he regarded her. "Try not to take it to heart. You know how Mustang can be when he loses his temper."

Levi scoffed, pushing himself off the wall. "He's still the same brat who does whatever he wants."

Christa shook her head, finally finding her voice. "No, it's... it's okay. I was just caught off guard."

Erwin sighed heavily, running a hand through his hair. "Honestly, I half expected him to throw the desk out the window... again."

"That was when you made him a squad leader," Levi reminded him, a hint of amusement in his voice.

Christa's eyes widened in surprise. "Really? But isn't being a squad leader a good thing?"

Erwin's lips quirked in a wry smile. "Mustang has never been fond of responsibility."

"It's because he wasn't born for it," Levi interjected. "When I first saw him in the Underground, I thought he had potential to be a decent soldier. It was Erwin who kept giving him more responsibilities."

Erwin nodded, his expression thoughtful. "He has good leadership skills when he's calm, and he's excellent with paperwork. I thought I could groom him to be the next commander, but..." he trailed off, shaking his head.

"What will happen to him now?" Christa asked, unable to keep the concern from her voice.

Erwin's face softened slightly at her obvious worry. "He'll be back, I'm sure of it. I just hope it's before the expedition."

Levi's eyes narrowed. "You need to punish him for this, Erwin."

"And will you be the one to throw him in a cell?" Erwin asked, raising an eyebrow. "The last time someone tried, he tossed Mike out a window."

Levi clicked his tongue in annoyance. "What is it with him and defenestration?"

As the two men continued their discussion, Christa found her mind wandering. The breakfast she had so carefully prepared now seemed insignificant in the face of the drama that had unfolded. She thought back to Aaron's words, his declaration that he would sacrifice her – sacrifice anyone – for his sister's sake.

Part of her wanted to be hurt, to be angry at his callous statement. But as she reflected on it, she realized that his words, harsh as they were, revealed a fundamental truth about Aaron Mustang. His love for his sister, his willingness to go to any lengths for her, was at the core of who he was. It was that same fierce loyalty and protectiveness that made him such an asset to the Survey Corps, even if he chafed under the weight of responsibility.

"Christa?" Erwin's voice broke through her reverie. "Are you alright?"

She blinked, realizing she had been lost in thought. "Yes, sir. I'm fine. I just... I think I understand Aaron a little better now."

Erwin's eyebrows rose in surprise. "Oh? How so?"

Christa took a deep breath, organizing her thoughts. "He's not really the type to blindly follow orders or accept responsibility he doesn't want. But when he cares about something – or someone – he's willing to do anything. Maybe... maybe instead of trying to force him into a role he doesn't want, we should focus on giving him reasons to want to protect humanity."

A slow smile spread across Erwin's face. "That's quite an insightful observation, Christa. Perhaps you understand our troublesome captain better than any of us."

Levi snorted, but there was a glimmer of respect in his eyes as he looked at Christa. "Not bad, kid. Maybe you can talk some sense into that idiot when he comes back."

Christa felt her cheeks warm at their praise. "I'll do my best, sir."

As she turned to leave, still holding the now-cold breakfast tray, Erwin called out to her. "Christa? Thank you for caring about him. Mustang needs people like you in his life."

.....

The stone corridors of the castle echoed with the sound of Aaron Mustang's furious footsteps as he stormed away from is office. His mind was a whirlwind of anger and frustration, his green eyes blazing with barely contained rage. The other soldiers he passed in the hallway pressed themselves against the walls, giving him a wide berth. The reputation of Aaron's temper preceded him, and no one was eager to be caught in its path.

As he rounded a corner, lost in his tumultuous thoughts, Aaron collided hard with another body. The impact nearly sent him stumbling, but he caught himself, his scowl deepening as he recognized the person he'd run into.

"Move it, Kirstein," Aaron growled, attempting to push past Jean.

Jean, however, stood his ground, his eyes narrowing as he took in Aaron's agitated state. "What's going on, Mustang?" he asked, a mix of concern and wariness in his voice.

Aaron's only response was to shove Jean roughly, trying to force his way past. But Jean, having grown both in strength and confidence over the past three years, didn't budge.

"I can't believe you're still the same brat throwing tantrums," Jean said, his voice tinged with disappointment. "I thought these three years might have changed you."

Aaron whirled around, his hands clenching into fists at his sides. The corridor suddenly felt too small, the air thick with tension.

Jean's eyes flickered to Aaron's fists, a bitter smile twisting his lips. "What are you going to do, hit me? That's your solution to everything, isn't it? Even poor Armin wasn't safe from your fists."

The mention of Armin sent a pang of guilt through Aaron, momentarily cutting through his anger. But he pushed it aside, clinging to his rage like a shield. "You don't understand," he spat.

"Understand what?" Jean shot back, his own temper rising to meet Aaron's. "That everyone here has lost something? That we're all sacrificing something? And yet here you are, disrespecting everyone because of what? Another one of your childish tantrums? Some leader you turned out to be."

With that, Jean turned on his heel and strode away, leaving Aaron standing alone in the corridor, his anger slowly giving way to a creeping sense of shame.

For a long moment, Aaron stood there, Jean's words echoing in his mind. As much as he wanted to dismiss them, to cling to his righteous anger, he couldn't shake the truth in what Jean had said. Everyone in the Survey Corps had suffered losses, had made sacrifices. What made his pain more important than theirs?

With a heavy sigh, Aaron ran a hand through his hair, mussing it further. The fight drained out of him, leaving him feeling hollow and slightly ridiculous. Swallowing his pride, he turned and made his way back to Erwin's office.

Standing before the heavy wooden door, Aaron took a deep breath, steeling himself. Then, with uncharacteristic hesitation, he pushed it open and stepped inside.

Erwin looked up from his desk, surprise evident on his face as he saw Aaron. Levi, still leaning against the wall, raised an eyebrow but said nothing.

"Um," Aaron began, a blush creeping up his neck as he struggled to find the right words. "I... I'm sorry. About earlier."

Erwin's eyebrows shot up, genuine shock replacing his usual composed expression. "Did Christa talk to you?" he asked, clearly trying to make sense of Aaron's sudden change of heart.

Aaron shook his head, the blush deepening. "No, it was... it was Jean, actually."

A small smile tugged at the corners of Erwin's mouth. "I see," he said, his voice warm with approval. "Well, you should probably talk to the girls as well."

Aaron nodded, relief washing over him as he realized Erwin wasn't going to make this more difficult than it needed to be. "I will," he promised.

Erwin's smile widened slightly. "By the way, you can go today. But I want you back here bright and early tomorrow morning."

Aaron's face lit up, a grin spreading across his features. "Thank you, sir!" he said, his voice filled with genuine gratitude.

As Aaron turned to leave, he caught sight of Levi rolling his eyes. "You coddle him too much," the captain muttered to Erwin.

Erwin chuckled, shaking his head. "Don't look at me. You're the one responsible for him. You brought him here, after all."

Levi clicked his tongue in annoyance, but Aaron could have sworn he saw a flicker of fondness in the captain's eyes.

With a lightness in his step that had been absent earlier, Aaron made his way out of the office and towards the stables. He had one more apology to make, and this one, he knew, would be the hardest.

The smell of hay and horses grew stronger as Aaron approached the stables. The large wooden doors stood open, allowing the warm morning sunlight to spill inside. As he stepped into the shadowy interior, his eyes adjusting to the dimmer light, he caught sight of a familiar figure.

Christa stood near one of the stalls, her golden hair catching the sunlight that streamed through the high windows. She was running a brush along the flank of a chestnut mare, her movements gentle and soothing. For a moment, Aaron simply watched her, struck by the peace of the scene and the grace of her movements.

Then, gathering his courage, he stepped forward. "Christa?" he called softly, not wanting to startle her.

She turned at the sound of his voice, her blue eyes widening in surprise. "Aaron," she said, her voice carefully neutral. "I didn't expect to see you here."

Aaron felt a twinge of guilt at the guarded look in her eyes. He knew he was the cause of it, and the knowledge sat heavy in his chest. "I... I came to apologize," he said, the words coming out in a rush. "For what I said earlier. About sacrificing you. I didn't mean it."

Christa's expression softened slightly, but she remained silent, waiting for him to continue.

Aaron took a deep breath, struggling to find the right words. "The truth is," he said, his voice low and intense, "I wouldn't sacrifice you. If anything, I'd sacrifice the world for you and Rosy."

The moment the words left his mouth, Aaron felt heat rush to his face as he realized the implications of what he'd just said. Christa's cheeks turned a deep shade of pink, her eyes wide with surprise and something else – something that made Aaron's heart race.

The silence that fell between them was charged with unspoken emotions, the air suddenly thick with tension of a very different kind than earlier. Aaron opened his mouth, though he had no idea what he was going to say, when a sudden movement caught his eye.

There, in the stall next to where Christa stood, was Eren. He was frozen in the act of brushing a horse, his eyes wide as he stared at Aaron and Christa. It was clear from his expression that he had heard every word of their exchange.

For a moment, the three of them stood in tableau – Aaron and Christa blushing furiously, Eren looking like he desperately wished he could disappear. Then, with a groan, Aaron broke the silence.

"I'm going to have to kill him," he muttered, only half-joking.

Eren's eyes widened even further, if that was possible. "I... I didn't hear anything!" he stammered, backing away slowly. "I was just... the horses... I'm going now!"

With that, Eren bolted from the stables, leaving Aaron and Christa alone once more.

Aaron ran a hand over his face, embarrassment warring with amusement. "Well," he said, a wry smile tugging at his lips, "that's one way to spread gossip through the corps."

Christa let out a soft laugh, the sound breaking the tension that had built between them. "I suppose we should be grateful it wasn't Connie or Sasha," she said, her eyes twinkling with mirth. "The whole castle would know by lunchtime."

Aaron chuckled, marveling at how Christa could so easily lift his spirits. The anger and frustration that had consumed him earlier seemed distant now, like a storm that had passed leaving clear skies in its wake.

"Christa," he said, his voice soft but serious. "I really am sorry about earlier. You didn't deserve to hear that, even if I didn't mean it."

Christa's smile softened, her eyes warm as she looked up at him. "I know, Aaron. And I forgive you. I understand how important Rosy is to you."

Aaron felt a wave of gratitude wash over him. How had he gotten lucky enough to have someone like Christa in his life? Someone who could see past his prickly exterior and understand the heart of him?

"Thank you," he said simply, pouring all his sincerity into those two words.

For a moment, they stood in comfortable silence, the sounds of the stable – the soft nickering of horses, the rustle of hay – creating a peaceful backdrop. Aaron found himself wishing he could freeze this moment, hold onto this feeling of understanding and connection.

But reality intruded, as it always did. The upcoming expedition, the responsibilities waiting for him, the complications of his feelings for Christa – it all hovered at the edges of his mind, demanding attention.

"I should go," Aaron said reluctantly. "I need to prepare for my trip to see Rosy."

Christa nodded, understanding in her eyes. "Of course. Give her my best wishes, won't you?"

"I will," Aaron promised. He hesitated for a moment, then added, "When I get back... maybe we could talk more? There's a lot I'd like to say."

A soft smile spread across Christa's face, lighting up her eyes. "I'd like that," she said softly.

As Aaron turned to leave the stables, a sudden impulse seized him. He paused mid-step, his heart racing as he considered the idea that had just flashed through his mind. Before he could overthink it, he spun back around to face Christa, who was watching him with a mixture of curiosity and concern.

"Christa," he said, his voice carrying a hint of nervous energy, "would you... would you like to come with me? To see Rosy, I mean."

Christa's eyes widened in surprise, a faint blush coloring her cheeks. "To see your sister?" she asked, as if unsure she had heard him correctly.

Aaron nodded, running a hand through his hair in a gesture of uncharacteristic shyness. "Yeah. I mean, if you want to. No pressure or anything. I just thought... well, she's always asking about my friends, and..." he trailed off, suddenly feeling foolish.

But Christa's face broke into a radiant smile, dispelling Aaron's doubts. "I'd love to," she said warmly. "If you're sure you want me there."

"I'm sure," Aaron said, a smile of his own spreading across his face. "Let's go before I change my mind and decide to be responsible for once."

Christa laughed, the sound light and musical in the quiet of the stables. "We can't have that, can we? Let me just finish up here and I'll meet you at the gates."

As Aaron waited by the castle gates, his mind raced with a mixture of excitement and nervousness. He had never brought anyone to meet Rosy before. His sister had always been a part of his life that he kept separate from his duties as a soldier. But somehow, the idea of Christa meeting Rosy felt right.

When Christa appeared, her hair glowing golden in the morning sunlight, Aaron felt his breath catch in his throat. She had changed into civilian clothes – a simple blue dress that brought out the color of her eyes. For a moment, he could almost forget they were soldiers, could almost imagine they were just two young people setting out on an adventure.

"Ready?" Christa asked, her smile tinged with a hint of nervousness that matched Aaron's own.

He nodded, helping her mount her horse before swinging up onto his own. "Let's ride," he said, and with a gentle nudge of his heels, they set off.

The journey to the capital was long, but it passed quickly in Christa's company. They talked and laughed, sharing stories of their training days and speculating about their comrades. Aaron found himself opening up more than he had in years, telling Christa about his childhood in the Underground, about the day he met Levi, about his dreams for Rosy's future.

As they approached the towering walls of the capital, Aaron felt a familiar mix of awe and resentment. The opulence of the inner city always struck him as obscene compared to the poverty he had grown up in and the constant danger faced by those in the outer walls.

"It's beautiful," Christa murmured as they rode through the bustling streets, her eyes wide as she took in the grand buildings and well-dressed citizens.

Aaron grunted noncommittally. "It's something, alright," he said, unable to keep the bitterness entirely out of his voice.

Christa glanced at him, understanding dawning in her eyes. "It must be strange for you," she said softly. "Coming from the Underground to... this."

Aaron nodded, grateful for her perceptiveness. "Every time I come here, I think about how different Rosy's life could have been if we'd been born up here instead of down there."

They fell into a contemplative silence as they made their way to the hospital where Rosy lived. It was a grand building, all white stone and gleaming windows. Aaron had to admit, if Rosy had to be confined somewhere, at least it was here, where she could receive the best care available within the walls.

As they dismounted and made their way inside, Aaron felt a flutter of nerves in his stomach. He glanced at Christa, who gave him an encouraging smile. Taking a deep breath, he led the way to Rosy's room.

The door was open, sunlight streaming in through large windows. And there, propped up in bed surrounded by books and drawings, was Rosy. At twelve years old, she was still small for her age, her body frail from years of illness. But her eyes, the same vibrant green as Aaron's, were bright and alert as she looked up at their entrance.

"Big brother!" she cried out, her face lighting up with joy. Then her gaze fell on Christa, and curiosity overtook her features. "Who's this?"

Aaron stepped into the room, Christa following close behind. "Hey, squirt," he said, his voice softening as it always did around Rosy. "This is Christa. She's... she's a friend from the Survey Corps."

Rosy's eyes widened, darting between Aaron and Christa with growing excitement. "A friend? Is she your girlfriend? Are you going to get married?"

Aaron felt heat rush to his face, glancing at Christa to see her cheeks had turned pink as well. "It's not like that," he stammered. "We're just... we work together."

But Rosy was not so easily deterred. "But she's so pretty!" she insisted. "And you've never brought a girl to meet me before. She must be special."

Christa stepped forward, saving Aaron from his floundering attempts at explanation. "It's lovely to meet you, Rosy," she said warmly. "Your brother has told me so much about you. I hope we can be friends too."

Rosy beamed at Christa, immediately won over by her kindness. "I'd like that," she said. Then, with the bluntness of youth, she added, "Even if you're not marrying my brother yet."

Aaron groaned, burying his face in his hands as Christa laughed. But despite his embarrassment, he couldn't help but feel a warmth in his chest at the easy way Christa interacted with Rosy.

As the afternoon wore on, the three of them fell into easy conversation. Rosy peppered them with questions about life in the Survey Corps, her eyes shining with excitement as they recounted (heavily edited) versions of their adventures beyond the walls.

"I'm so proud of you, big brother," Rosy said at one point, her voice filled with admiration. "I can't even leave this room, but you get to go outside the walls and fight for humanity."

Aaron felt a lump form in his throat at her words. He reached out and took her small hand in his, marveling at how fragile it felt. "I do it for you, squirt," he said softly. "Everything I do out there is to make the world safer for you."

Rosy squeezed his hand, her eyes shining with unshed tears. "I know," she whispered. "And one day, when I'm better, I want to see that world with you."

The moment was interrupted by a nurse entering to check on Rosy. As she fussed over her patient, Aaron and Christa excused themselves, stepping out into the hallway to give Rosy some privacy.

Once outside, Aaron leaned against the wall, letting out a heavy sigh. "Thank you for coming," he said, turning to Christa. "It means a lot to me. And to Rosy."

Christa smiled, reaching out to place a comforting hand on his arm. "Thank you for bringing me," she said. "Rosy is wonderful. I can see why you fight so hard for her."

Aaron nodded, feeling a swell of emotions he couldn't quite name. "She's all I have," he said softly. "Or... she was."

The words hung between them, heavy with implication. Christa's hand tightened slightly on his arm, her blue eyes meeting his green ones with an intensity that made his heart race.

"Aaron," she began, but whatever she was going to say was cut off by the nurse exiting Rosy's room.

"You can go back in now," the nurse said with a smile. "But not for too long. She needs her rest."

They spent another hour with Rosy, laughing and talking until the young girl's eyelids began to droop. As they said their goodbyes, Rosy pulled Christa close and whispered something in her ear that made the older girl blush and laugh.

The ride back to the Survey Corps headquarters was quieter than the journey there, both Aaron and Christa lost in their own thoughts. As the sun began to set, painting the sky in brilliant oranges and pinks, Aaron found himself stealing glances at Christa, marveling at how the fading light turned her hair to spun gold.

When they finally arrived back at the castle, dismounting their horses in the quiet courtyard, Aaron felt a reluctance to let the day end.

"Christa," he said, as they led their horses to the stables. "Thank you again for today. It... it meant a lot to me."

Christa smiled up at him, her eyes soft in the twilight. "I'm glad I could be there," she said. "Rosy is amazing. I can see why you love her so much."

Aaron nodded, feeling a lump form in his throat. "Yeah, she is," he agreed. Then, gathering his courage, he added, "But she's not the only amazing person in my life."

Christa's eyes widened slightly, a blush creeping across her cheeks. For a moment, they stood there in silence, the air between them charged with unspoken emotions.

Finally, Aaron cleared his throat. "We should probably get some rest," he said reluctantly. "Early start tomorrow and all that."

Christa nodded, though she made no move to leave. "Aaron," she said softly. "I... I'm glad you let me in. Let me see this part of your life."

Aaron felt a warmth spread through his chest at her words. "Me too," he said, his voice barely above a whisper.

As they parted ways, each heading to their own quarters, Aaron found himself filled with a sense of possibility he hadn't felt in years. The challenges ahead were still daunting – the upcoming expedition, the constant threat of the Titans, the weight of his responsibilities. But for the first time in a long time, he felt like he had something to fight for beyond just survival.

.....

The sun hung high in the cloudless sky, its relentless heat beating down on the long formation of Survey Corps soldiers as they rode across the vast, open terrain beyond Wall Maria. The rhythmic thunder of hooves against packed earth filled the air, punctuated occasionally by the sharp crack of a signal flare or the distant, haunting roar of a Titan.

At the center of the formation, Captain Aaron Mustang sat astride his black stallion, his eyes heavy-lidded and unfocused. A jaw-cracking yawn escaped him, drawing an exasperated look from Nanaba, who rode beside him.

"For heaven's sake, Captain," Nanaba chided, her voice tinged with concern. "Didn't you get any sleep these past few days?"

Aaron shrugged, rolling his shoulders to work out the stiffness that had settled there during the long ride. "Slept fine," he mumbled, stifling another yawn. "Just bored out of my mind."

Nanaba's eyes narrowed, clearly not buying his nonchalant act. "This isn't some leisurely ride through the countryside, sir. We're in Titan territory. You need to be alert."

"I'm always alert," Aaron retorted, though the effect was somewhat ruined by yet another yawn.

The truth was, Aaron's mind was far from the monotonous expanse of land they were traversing. His thoughts kept drifting back to the day he'd spent with Christa, visiting Rosy. The memory of Christa's smile, the way she'd connected so easily with his sister, the unspoken tension that had hummed between them on the ride back – it all swirled in his mind, a pleasant distraction from the grim reality of their current mission.

But Nanaba was right, of course. This was no time for daydreaming. They were deep in enemy territory, surrounded by dangers both seen and unseen. Aaron straightened in his saddle, forcing himself to focus on their surroundings.

As if on cue, a soldier from the right flank of the formation rode up alongside them, his face etched with worry. "Captain Mustang," he called out, his voice tight with tension. "We've lost contact with several squads on the outer edges of the formation."

Aaron felt a chill run down his spine, instantly alert. Lost contact could mean any number of things, none of them good. "How many?" he asked, his voice sharp.

"At least three squads, sir," the soldier replied. "No response to signal flares, no messengers."

Aaron's mind raced, calculating possibilities. A group of Titans could have broken through their defenses, picking off the outer squads. Or perhaps they'd encountered some kind of abnormal that their standard tactics weren't prepared for. Whatever the case, they needed to react quickly.

"Nanaba," Aaron began, turning to his second-in-command, but his words died in his throat as something caught his eye.

In the distance, moving with a speed that defied belief, was a Titan unlike any Aaron had ever seen. Its body was lean and muscular, distinctly feminine in form, with short blonde hair that gleamed in the sunlight. But it was the way it moved that truly set it apart – not the lumbering gait of a normal Titan, but a purposeful run that spoke of intelligence and intent.

"What in the walls is that?" the messenger soldier gasped, his eyes wide with fear and disbelief.

Aaron's mind whirled, pieces falling into place with terrifying clarity. The lost squads, the abnormal behavior, the human-like purposefulness of its movements – it all pointed to one impossible conclusion.

"It's like Eren," Aaron breathed, his voice barely above a whisper. "A human who can transform into a Titan."

The implications of this realization were staggering. If there were other humans who could become Titans, who were they? Where did they come from? And most pressingly, what were they after?

Before Aaron could voice any of these questions, the messenger soldier spurred his horse forward. "I'll take care of it!" he called out, determination overriding his earlier fear.

"Wait!" Aaron shouted, but it was too late. The soldier was already engaging his ODM gear, the hiss of releasing gas cutting through the air as he launched himself towards the Female Titan.

Time seemed to slow as Aaron watched the scene unfold. The soldier, brave but hopelessly outmatched, swung around the Titan's body, aiming for the nape of its neck. For a moment, it looked as though he might succeed – his blades flashed in the sunlight, poised to strike the Titan's weak point.

But then, in a display of agility that no normal Titan could hope to match, the Female Titan reached out and grabbed the soldier's cable mid-swing. With a casual flick of its wrist, it sent the man flying, his scream of terror cut short as his body impacted against a distant tree with a sickening crunch.

"Holy shit," Nanaba breathed, her usual composure cracking in the face of this unprecedented threat.

Aaron's mind was already racing, formulating strategies and discarding them just as quickly. This was no ordinary Titan – their usual tactics would be worse than useless against an opponent with human-level intelligence and the raw power of a Titan.

"Nanaba," Aaron said, his voice low and intense. "Send up a black flare. We need to warn the rest of the formation."

As Nanaba complied, loading the flare gun with practiced efficiency, Aaron's eyes never left the Female Titan. It had paused in its advance, its unnaturally human eyes scanning the horizon. Looking for something – or someone.

"What's the plan, Captain?" Nanaba asked as the black smoke of the warning flare curled into the sky above them.

Aaron's jaw clenched, his hand moving almost unconsciously to the handles of his ODM gear. "We need to slow it down," he said, calculation and determination warring in his voice. "Buy time for the rest of the corps to regroup and come up with a plan to capture it."

Nanaba's eyes widened. "Capture it? Sir, with all due respect, that thing just swatted one of our best soldiers like a fly. How do you propose we—"

But Aaron was already moving, swinging himself off his horse with fluid grace. "Keep the horses nearby," he ordered. "We might need a quick escape. And Nanaba?" He paused, meeting her worried gaze. "If this goes south, your priority is to get back to the main group and warn Erwin. Understood?"

Nanaba looked like she wanted to argue, but years of working under Aaron had taught her when his mind was made up. She nodded sharply, though the concern never left her eyes. "Understood, Captain. Be careful out there."

Aaron allowed himself a grim smile. "Careful isn't really my style, Nanaba. You know that."

With that, he engaged his ODM gear, the familiar rush of gas propelling him into the air. As he soared towards the Female Titan, wind whipping through his hair and adrenaline surging through his veins, Aaron felt a clarity he hadn't experienced in years.

This, right here, was what he was made for. Not the paperwork, not the responsibilities of leadership, but this – the thrill of facing an impossible opponent, the knife-edge balance between life and death. In this moment, with danger looming large and the lives of his comrades hanging in the balance, Aaron Mustang was truly alive.

As he neared the Female Titan, its ice-blue eyes locked onto him with unnerving focus. Aaron could almost imagine he saw recognition in those too-human eyes, a flicker of something that went beyond mere bestial hunger.

"Alright, you blonde bitch," Aaron muttered under his breath, his hands tightening on his blade handles. "Let's dance."