A/N: I confess, I'm struggling slightly with writing my multi-chapter story, Forbidden Magic. The storyline's in my head, it's just getting difficult to word everything correctly.
So, as you do, I decided to focus on this one-shot instead. I really liked writing it, and I'm hoping my writer's block will disappear soon enough.
Warning: contains major spoilers if you're not caught up with the Manga.
Also, I finished writing this at 2 in the morning, so expect spelling errors.

Disclaimer: I own nothing but the storyline and the original character of Maximillion Acre.

Enjoy!

"You can't smell them at all?" I asked, looking over at a frustrated Natsu.
"It's like in Edolas – everything smells different in the west. There's too much going on." Natsu whined, holding his nose as if he was consoling it for its failure.

"Do you think there are exceeds in the west?" Happy flew down to us, abandoning his post as a bird-eye view. I assumed he hadn't spotted the rest of our group either.
"We can always go searching for one, buddy!" Natsu grinned at his blue companion.

"No, we can't. This is an infiltration mission, remember? The only person we're searching for is Makarov." I sighed. As much as I hated to darken the upbeat mood Natsu and Happy were attempting to create, I couldn't let them get off-track.

But I couldn't find it in myself to let my stress get to me when I saw their faces fall.
"Okay, fine, we can look for exceeds. But only if we happen to find one during our task to find the master. Sound good?" I caved, allowing myself a small smile when Natsu hugged me in gratitude. Happy was whizzing around in the air with excitement, and it occurred to me that he didn't really get to converse regularly with much of his own species.

Nevertheless, the fools were over-reacting in their effort to lighten the tension of being split up from the others. If they didn't quieten down soon, they were bound to draw attention-

"My my, I thought Lady Brandish wiped all you Fiore wizards out at Caracolle Island?" an unfamiliar voice drawled from behind us.
My first reaction was to spin around and assess the situation.
Natsu's first reaction was (surprise, surprise) to fly towards the intruder fist first, without even a glance.

I couldn't blame him, to be honest. Getting the upper hand with these foreign wizards was key, it seemed. And this guy was definitely a wizard – I could feel the magical pressure from where I stood.
I smirked when Natsu's fiery fist connected to the man's face; the latter's purple eyes opening wide in surprise as his lanky body was thrown several metres away.

That guy definitely didn't look like a fighter…
Logically, I knew that it was best to just knock him unconscious and continue with our mission. We shouldn't underestimate the wizards here.
But I couldn't help feeling guilty at the fact that I was about to fight someone who wouldn't fight back.

But that magic pressure I felt?
If it wasn't put into physical strength, then this battle would definitely not be suited for Natsu. We had to knock this guy out before he was able to use his magic.

Coming to my conclusion, I turned to Natsu. His expression was torn as he looked at the wizard he had just attacked, and I assumed his trail of thought was similar to mine.
"Knock him out, quick. I think that's the only way-"

I trailed off when Natsu's eyes locked with mine, his head turning so fast I barely registered the movement.
The look in his eyes was one I had seen many times since I met him. His face was darkened, his eyes reminding me of headlights capable of stunning people, making them freeze on the spot. I could see veins bulging angrily on his forehead, as he gave me a full view of his dangerous looking canines.

But he wasn't smiling.
This was the look I had seen directed at Natsu's enemies. Only the ones that really pissed him off. Future Rogue. Raven tail at the grand magic games. And now, me.

Every instinct in my body was telling me to run. I was used to ignoring it, but this sudden change in events had me debating whether it would be best for me to listen to it for now.
No, Natsu would never hurt me. Maybe there was another enemy behind me? Yeah, that had to be it.

"Natsu?" Happy sounded cautious as he flew towards his oldest companion.
The dragon slayer's cold eyes darted towards the blue cat, his expression unchanging. However, his battle stance became more ready as the distance between the boy and his exceed reduced.

The hair on the back of my neck was standing up. Before I could shout out to warn Happy, the space he was formerly occupying was replaced by fire. I could barely comprehend what I had just seen.

Natsu just attacked his best friend. As I watched the scene in horror, I saw Natsu smirking in my peripheral vision.
"Filthy animal" the words sounded foreign coming out of his mouth.

Something was wrong.
Something was very wrong.
This was a nightmare. Why was this happening?

Happy…
"HAPPY!" I screeched, finally able to move. The fire was now gone; Happy had been thrown against a tree after being propelled backwards. I sprinted towards the cat, registering as I approached that his eyes were open. He looked slightly burnt, but he was alive, at least.

His wide eyes, formerly fixed on Natsu, landed on me tentatively as I approached.
"Lushy, why's Natsu evil now?" He asked, near tears.
I simply shook my head at him before turning back around to check on our pink-haired companion.

He had approached the foreign wizard while I ran to Happy, and was now helping him up.
"Thank you… Natsu I presume? I'm Maximillion Acre, Member of the Alvarez imperial army. Pleased to meet your acquaintance" his sickeningly polite tone gave me shivers.

I was baffled by the carefree smile Natsu gave to our enemy.
Then it clicked.
Natsu's sudden change in behaviour… it had something to do with Acre's magic. I was sure of it.

"What did you do to him?" I demanded, standing up defiantly.
"Whatever do you mean, girl?" the lanky man smirked while Natsu growled at my outburst. "I simply changed his perspective a little. I figure he'd be a fine recruit to our army, do you not think?" he continued, glancing at Natsu's anger towards me with pride.

"He'll never join your army!" I cried. Okay, so he'd altered Natsu's memories or something. But what was all of this about perspective, though?
Natsu was treating me and Happy, his friends, like his enemies.
He smiled at Acre like he wasn't a threat.

Perspective…

Acre's deadly chuckle interrupted my thoughts.
"Oh, but he will. I get the feeling this boy's opinions on several things may have… switched." And with that, the foreign wizard gave Natsu a light push in my direction.

His opinions have switched?
I watched in dismay as my best friend stalked towards me, fire engulfing his limbs.
If I was formerly his friend… then it seemed that Acre had now made him my enemy.

I'd always been truly terrified for the people who ended up unleashing this side of Natsu.

"It's always more fun only using my magic on one member of a team, and then sitting back to watch them destroy their own friends." the foreign wizard's polite tone was now dripping with insane malice as it became background noise to the turmoil in my head.

The truth is that I'd been raring for a spar with Natsu ever since he left me for that one year. I'd thought of ways I could actually beat him, knowing I'd be able to rely on strategy and my newfound star-dress powers rather than physical strength.

But in the scenarios I'd thought up, Natsu was always smiling. He would praise me when I overpowered him and he would tease me when I slipped up. Then we'd laugh and start again.

I didn't want to fight Natsu. Not like this. Not when he was aiming to kill rather than have fun. Not when Happy was defenceless behind me, too injured to move.

It was Tartaros all over again. I was left alone with the immense responsibility of protecting both Happy and myself. I had to remember that Natsu was a victim here even though he was the attacker; he would never be able to forgive himself if he killed us.
I had to do this.

But I was frozen.

Time seemed to slow down as I saw my best friend lift one of his flame-coated arms, a crazy gleam in his eyes. I felt the temperature rise dramatically as an inferno extended from him, aiming to encase me in fire.

And just like back when I was facing Jackal, I felt Aquarius' magic surrounding me like a warm hug.

"Even though I hate you,-"
My eyes widened under the spirit's protective water as it shielded me from Natsu's flames. It was her voice. She sounded so far away…

"-I can't stop these emotions"
I looked around frantically for any sign of her, but all I could see was fire. It was engulfing me, and I could feel Aquarius' protection steaming from the contact.

Although the warmth was bearable, I realised after a few seconds that breathing wasn't an option. The flames were using up all the oxygen in the air, leaving me with none.

I just had to hold on for a few more seconds. It was the least I could do since my oldest spirit was shielding me. Mavis knows how she was doing it, but if I could, I would be crying tears of joy.

"I've missed you too, Aquarius" I whispered.

"NATSU, STOP! SHE'S DYING, NATSU! YOU'RE KILLING LUCY!" I could hear Happy screaming from outside the flames as they died down slightly.

Okay, Aquarius. If you're going to defy odds by protecting me yet again, I'm sure I can defy the odds by subduing Natsu. No more whimpering. I need to do this.
And on that thought, I felt my legs moving me out of the ball of fire. After a few moments, I found myself able to breathe again.

"Happy, go find the others. I can deal with this." My voice was steady and laced with determination. I couldn't see just yet because my eyes were adjusting back to the normal lighting, but I assumed the dependable exceed had found his strength and was able to fly.

"Lushy… How…" Happy asked; his voice a mix of relief, confusion and fear. I would have to answer his questions later.
"Trust me." I requested, smiling. I could see his vague outline now, still refusing to budge.
Did he not realise that I was the only person present who could handle Natsu right now? Did he not believe in me? I was about to shout at him to just go, but it was in that moment that the blue blur, now rapidly becoming more focused, finally moved.

"Don't die, Lucy!" he yelled as he flew away. And as my sight returned to normal, I saw that two of the fingers on his paw were up.
The signature Fairy Tail salute only gave me more confidence.

Taking a deep breath, I turned back to Natsu.
To my surprise, his expression was not full of hatred for me. Instead, he was clutching his head, his fingernails digging into his scalp. His eyes were focused on where he had trapped me in the flames; the fire was now just a fraction of what the initial attack had been.

The insane anger was still there, but I could see that several new emotions were now going through his mind. His posture suggested guilt. The shape of his eyes suggested… agony.
This was him… this was my Natsu. He was fighting whatever Acre had done to him.

"Natsu… Natsu, it's okay." I said quietly, approaching him like I would approach a cornered animal. "It's Lucy. I'm okay. You didn't hurt me."

If he heard me, then he didn't have it in him to acknowledge me right now. However, I could see the veins on his forehead sinking back to normal as he breathed deeply.

I slowly walked closer to him, my aim being to hug him. Reinforce the idea that I'm his friend, not his enemy. Maybe that would be all it took to resolve his internal conflict?

When he finally decided I look at me, that's when I knew. I was being naïve.
My realisation came too late. I watched his fist sink into my abdomen as he punched me; feeling my back hit the floor several metres away before I felt the excruciating pain in my ribs.

I coughed up blood, and thoughts of 'what would Natsu do in my situation?' came into my head. He would get up. He would keep fighting. It didn't matter if the person I took that advice from was the person attacking me.

Grabbing Loke's key, I quickly summoned both him and the accompanying star dress. Feeling the celestial magic fill me as my clothes changed, I was rejuvenated by a familiar strength. The pain in my ribs was still there, but I focused on ignoring it as I stood up next to the lion spirit.

Immediately sensing the tension, he looked at me worriedly.
"It's Natsu… he's-"
"FIRE DRAGON'S ROAR!" the dragon slayer bellowed, forcing Loke and I to dodge in different directions.

Upon landing, I lunged directly for Natsu, feet first. He turned to me and smirked mockingly, reaching for my ankle.
But he'd already used that trick on me before when I tried to Lucy-kick him in my apartment. Plus, this star dress increased my agility exponentially.

Using my left leg to kick away his approaching hand, I felt right foot connect directly with his face. A ball of Regulus' gold light exploded from my body, sending the dragon slayer flying.
I figured this would give me enough time to catch Loke up.

"Natsu's under some sort of spell. He thinks his friends are his enemies and vice versa-"
"Princess!" Loke shouted, rocketing into me, sending me a few metres to the side. It took me a few moments to realise that Natsu had recovered faster than I expected him to. Flames engulfed the area I had been standing just two seconds ago.

I mentally facepalmed when I realised just how naïve I'd been again.

"Tsk. Trash." Natsu taunted as Loke and I adopted combat positions again.
It was the first thing Natsu said to me since the spell was put on him. And it hurt. Because right now, a small part of me believed him.

"Snap out of it, Natsu!" Loke shouted, only to receive a direct attack from the dragon slayer. It was dodged, and in that moment my eyes connected with the spirit's dark ones. We knew what to do.
"DUAL REGULUS IMPACT!" we roared simultaneously, punching Natsu in a way that made him spin on the spot, disorientating him.

What we didn't anticipate was Natsu unleashing a spiral of fire as he spun, causing both me and Loke to jump back a safe distance from him.
Better strategy and structure. That's what I needed to end this quickly with minimal damage to Natsu. I just needed a way to knock him out until I figured out a way to undo the spell.

"Open, gate of Capricorn!" I called, reminding myself that there was no time for explanations. I trusted the intelligent spirit to gather what was happening by himself.

Natsu had meanwhile stopped his spinning and fire spewing, and since he looked mildly sick, I knew now would be the best time to attack.
Leaving Capricorn to assess the situation, I leaped towards Natsu, attacking him at every opening I could find whilst blocking his fiery punches. Loke was attacking him too, and eventually Capricorn joined the fight, making it three-on-one.

One would think he'd be overpowered by these odds, but there were times when neither I nor my spirits could get close to him due to his insane temperature. Aquarius's magic had long since worn off. He could burn me now.

His hits were having a significant effect on me; his reaction time being impeccable as always. I was fast, yes, but I needed more strength if I was to withstand all the attacks I failed to block.
Retreating slightly to allow Capricorn and Loke to occupy him for a few seconds, I closed my eyes and assessed my magic reserves.

I hadn't bought out three spirits since Tartaros. It seems that I had enough to do it again. I had no choice. Happy left Natsu in my hands. I would not fail his trust.
Here goes nothing.

"Open, gate of Taurus!" I recited, also replacing Leo's star dress with Taurus'. My magic reserves dropped significantly and I was feeling the strain, but I could keep going. For a few minutes, at least.

I jumped back into the fight, no longer able to produce explosions from my fists, but now able to take more damage from Natsu.
But no matter how many times I tried to attack his openings; no matter how strategically Capricorn arranged our fighting; no matter how devastatingly hard Taurus swung his axe; no matter how damaging Loke's punches were… Natsu was able to fight us all, his focus only increasing as I added my spirits into the battle.

This had to stop. I was running out of magic, fast.
Everything pointed to that one spell. The last resort for a celestial mage.
If I called back all of my spirits now, I would probably have enough magic left to cast Urano Metria with Gemini, and knock Natsu out. I shivered when I thought of the last time I used that spell.

I now knew it had the power to kill. I didn't regret killing that demon, but just knowing I had that sort of power made me uncomfortable.

No time to think about that, Lucy. Just cast the spell. You don't have near enough magic left to kill him anyway.
On that thought, I called back Loke, Taurus and Capricorn, undoing my star dress as well. Natsu was breathing heavily from the fight, and seemed to be watching me almost curiously.

I know I had little time before he took advantage of this opening.
I called out Gemini, my legs wobbling from the strain on my magic. I just had to hold out for a bit longer…

I grabbed Gemini's hands and the spirit seemed to read my mind; a replica of me appeared almost immediately. We started chanting.

"Survey the Heavens, Open the Heavens...
All the stars, far and wide...
Show me thy appearance...
With such shine.
Oh Tetrabiblos... "

Natsu's eyes widened as our scenery changed into a colourful representation of space with orbs surrounding us.
I had to focus on my magic now… I'm sorry, Natsu. I hope we find a way to break the spell after this.

"I am the ruler of the stars...
Aspect become complete...
Open thy malevolent gate.
Oh 88 Stars-"

"Okay, okay! I give up, Luce, this space thingy is giving me the chills!"

I stopped dead in my chanting, barely noticing as my surroundings shattered back into the woods we'd been fighting in.
Natsu had his hands up, surrendering, with a huge grin overtaking his face.

Gemini, sensing the lack of danger, took their leave with a cheery goodbye that I vaguely registered.
All I could do was gawk at the pinkette in front of me. Was this a ruse? No, I'm sure that neither version of Natsu would be that good an actor.

The only other alternative is…
"Damn flame brain, calling it off before it got to the good part!" Gray whined to the left of me, making me jump.
"Three spirits at a time is impressive, I believe? You've certainly improved, Lucy." Erza put her hand on my right shoulder, and I prayed she wouldn't bring me in for a hug. I'd had enough head trauma for today.

That was when I noticed Happy approaching us, carrying an unconscious body in his arms. The majority of my questions were answered simultaneously by this sight alone.
"How long has Acre been unconscious?" I asked, reassured that the spell on Natsu had been broken.

"A few minutes." Happy answered, sounding every bit as relieved as I felt.
"Anyway, Happy told us all about the parts of your fight that we missed." Gray sounded casual, but there was a questioning undertone in his voice.

I laughed awkwardly. They probably wanted to know why I was fire-proof all of the sudden.

"Yeah, you must've done a number on me, Luce. I can't even remember how the spar started! You and Loke and that goat man were suddenly just fighting me and I was like, hell yeah, I haven't had a good fight in ages!" Natsu laughed.
So that's why he was acting so carefree… he didn't remember.

"You must tell us all about it after we find Master- I mean Makarov." Erza's eyes darted to Natsu cautiously as she said this and I received her unspoken message; it would probably best if we didn't tell Natsu he'd tried to kill me and Happy.
There's no telling how he'd handle that sort of news.

"Wait… when did you guys show up? We've been looking for you for ages!" Natsu questioned his two team mates, who face-palmed at their friend's short attention span.
"We've been watching you guys spar for at least 5 minutes, numbskull! Pay attention to your surroundings!" Gray shouted.
"Why don't you pay attention to your clothes, stripper!" Natsu retorted, earning a gasp from his rival as he noticed that the dragon slayer actually had a point.

As Erza went through the usual routine of scaring the boys senseless, I sighed to myself. Happy perched next to me and we shared a look of understanding.
"I'm so glad he's back to normal." I said, holding back my tears.

I hoped that my forgiving nature would allow me to overcome the fear that I had faced today at the hands of my best friend.

oOoOoOoOoOoOoOoOo

"Luuuuuuuuce wake up. Luuuuuuuuuu-"
"There are ways to wake me up other than poking my face, you know." I yawned, sitting up to face Natsu.

I subconsciously checked his expression for any sign of ill intent, feeling relieved when there was none. Of course there wouldn't be any. The spell was broken. I'd never have to face angry Natsu again.

I've felt compelled to repeat those words a lot to myself for the last few hours.

"I'll tape fish to your nose next time. That always wakes Happy up." Natsu joked, and I slapped him lightly on the arm, giggling.
"So why did you interrupt my beauty sleep?" I asked, still slightly irked that he'd woken me up before sunrise.
"It's about earlier on today – the spar."

I sighed. "For the last time, if you want a rematch then you're going to have to wait-"
"No, it's not about that" he interrupted, his voice cold.

I waited for him to continue.

"I remember something. I think happy was screaming. Something about me… killing you." He was shaking. "I didn't know what was happening. Everything was dark. What happened, Luce?"

I sat up, taking a deep breath before I took his hand.
"It wasn't your fault, Natsu. Nobody blames you. That Acre wizard – the one that Mest took away for questioning – he put a spell on you. It's over now."

The boy looked at me, guilt written all over his features.
"And he made me attack you? And Happy as well?" he asked delicately.

"You thought we were your enemies."

Silence.

"It turned out okay though, didn't it? Nobody got hurt and-"
"I heard Wendy mention you had broken a rib." Natsu interrupted sternly.

"What do you want me to say, Natsu? You know I don't blame you." I retorted.
"I want you to not keep me in the dark, weirdo. Plus, you've had a strange look in your eyes ever since our spar. You can't just pretend things are okay when they're not." He argued grumpily.

"I'm sorry, Natsu. I'm just a bit cautious that the next time I see you, it's not going to be you. You'll see me as your enemy again." I admitted.

I squealed in shock when he grabbed my cheeks in his hands, bringing them closer to his face so that all I could see were his eyes. They were warm; staring intently into my eyes almost passionately.
I felt my cheeks warming up; the cause not being Natsu's hands.

"I promise I will never see you as an enemy. We'll always be best friends, no matter what." he said, and I felt every hidden pocket of distrust in my mind slowly emptying. I believed him.
"I promise that too. And a celestial wizard never breaks her promise." I smiled.

We stayed like that for a few seconds until I realised just how close we were to each other. Blushing and coughing, I pushed his hands away, increasing the space between us.
"Sorry about keeping you in the dark as well. We sort of thought you'd go on a rampage or something. We needed that Acre guy for questioning before you killed him." I joked, trying to erase the previous tension between us.

The sound of Natsu hitting his flame-engulfed fists together made me jump.
"So that means he's mine once Mest is through with him?" He asked excitedly, the terrifying side of him becoming more blatant the longer he sat there, possibly thinking of ways to beat the western wizard up.

Sweat-dropping at the hot head's sudden change in behaviour, I lay back into my makeshift bed. I was content that Natsu's anger wasn't focused on me.