Summary: Spoilers for Chapter 470, Natsu and Zeref hold off their final battle in order to fulfil an ancient alliance. My theory on what could happen next.

Pairings: Implied Dragon Slayer friendships, brotherly Zeref/Natsu, implied Natsu/Lucy, implied parental Igneel/Natsu, and if you squint, some implied Igneel/Zeref/Anna friendship.

Author's Note: Thank you all so much for giving me over NINETY THREE HUNDRED reviews!

Wendy's scream had pierced through the air.

It was expected, as horrible as it was, because they were in a war, but Damnit! They had been in a war with Zeref not Acnologia! The fearsome monster had attacked Sting and Rogue while they were fighting on the front, without a second thought, from the moment he heard, Natsu had leaped out of bed and made Happy fly him here. Gajeel and Wendy had been hot on their tail, and he was momentarily surprised when Laxus and Cobra also turned up when things started to look back.

Momentarily, in the end it didn't surprise him at all. They were all, after all, Dragon Slayers and this was the Dragon they were destined to kill.

And then it all went to shit.

Nothing, nothing, they did seem to have a lasting effect on Acnologia. Whatever advantage they gained was taken back in an instant. Cobra was now virtually out cold, his eye lids twitching was the only sign he was even alive, Laxus was panting against the gravel as he fought just to stand, Sting and Rogue were coughing up blood, and Gajeel only moved in time to catch Wendy as Acnologia threw her body in the air as if she was nothing but a ragdoll, which only caused him to rip open a barely healed wound.

And then Natsu….Natsu could barely breathe, his chest ached, his limbs felt heavy, his head was killing him, and he could taste the copper tang of blood in his mouth. He could barely see because he had so much blood smeared over his face.

He groaned and tried to get up, for a moment he almost succeeded but he then promptly collapsed again, and was only just able to catch himself on his elbows as he gasped for breath.

Acnologia laughed.

It was a cold, evil, cackle straight out from a fairy tale story and it sent shivers down Natsu's spine. "This was far too easy," Acnologia gloated as he walked casually about in his human form, "how did I even think you could be a threat when all you are is children." He kicked Sting hard, and the boy cried out in agony. "Little babies," Acnologia cooed sadistically, "don't worry, I'll put you out of your misery."

He raised his arm to strike at Sting and Natsu immediately took the opening to shoot out an attack…..it failed.

It failed miserably.

Acnologia stared at him with cold, empty, eyes, and Natsu fought back the urge to shudder. He wasn't going to show weakness right now, this was a battle of wills as well as fire power, he was not going to give this monster what he so obviously wanted.

"You!" Acnologia hissed. "You always were an impertinent brat, Natsu Dragneel," he growled furiously. "You do not wish to go last? Then I shall grant you, your wish," he strides across the barren wasteland they have made together with such ease that it looked as if he was flying, his arm is stretched out, ready to strike, "Good night sweet Prince," he said mockingly, "may hell keep you this time round."

And then his arm lashed out.

Natsu closed his eyes as he thought about everyone, his friends, his family, Igneel, Happy, and Lucy – Oh God! He choked at the thought, he will never have that future he hinted at, the one she cautioned him to not brag about, I am so sorry Luce – and accepted his fate with dread….and then waited….and waited some more…..and then….

Natsu opened his eyes to find Acnologia was frozen above him. The Dragon's eyes were wide with horror as his body stiffened against the gold binding that were fiercely digging into his tanned skin. Acnologia made such tiny whimpers that for a moment Natsu almost thought he was human…..and then his face twisted in the most hideous and ugliest looks of unadulterated hatred and fury.

"I know this magic!" Acnologia snarled. "It has been years since I've tasted it but I would know it anywhere." He let out an animalistic roar that made the world shudder. "HEARTFILLA!"

"L-L-Lucy," Natsu stammered as he struggled onto his knees, "Lucy…..how?"

She was here.

She was here and she was the one holding Acnologia captive. Her feet dug into the ground, her muscles were straining, she grunted and whimpered, and her eyes flashed fiercely, as she pulled with all her might to keep Acnologia stuck in the golden net she had casted.

How did she even get here?!

"I brought her," a soft voice said to his right, "teleportation is a small matter for the likes of me."

Natsu jerked as he met the dark eyes of Zeref.

He really, really, wishes he could say they were just as empty and cold and monstrous as Acnologia's but they weren't, and that's what made it a billion times worse.

Zeref titled his head and smiled gently. "You always know how to get into the worst of trouble," he said fondly, "luckily for you that someone has always been there to catch you."

Natsu shook at that. He didn't need another reminder of how fucked up his life is right now. He didn't want to remember that this was his brother. "Why?!" he grounded out.

Why was he here? Why was he helping them? Why did he put Lucy's life in such terrible danger?

Zeref didn't answer him as Acnologia chose that very moment to transform into a dragon once more. His wings broke the golden binding and sent Lucy flying into a tree. Natsu jumped to catch her on sheer instinct.

"LUCY!"

He never got near her as Zeref grabbed his arm and pulled him back against him, his other arm shielded Natsu from the violent gusts of wind that Acnologia's wings were causing. "Don't," he whispered in Natsu's ears, "Lucy can take care of herself, little brother. You will only cause more trouble if you jump in without a second thought.

At this point Lucy had transformed into her Taurus star dress and was already on the offence against Acnologia.

Natsu struggled all the more against Zeref's arms. "How do you know?!" he spat out. "You don't know her!"

Zeref stared at him with dry amusement. "I think you will find that I know her better than you think," he said calmly, "she is a Heartfilla. There has never, not once, been a Heartfilla that Acnologia could outwit."

Natsu's head spun at that. It was all too confusing. Lucy, Acnologia, the whole thing with the Dragons and the time travel, the fact the most evil man in all of history was his brother, and that he was acting like he was the good guy right now….

Natsu really just wanted to go back to sleep and find out this was all a dream.

"I thought you wanted to destroy the world," Natsu said numbly, "so why are you here?"

Something terrifying flashed in Zeref's eyes. "Acnologia stole something beloved from me," he said, his hand patted Natsu's cheek momentarily and Natsu flinched at the gentleness of such a creepily familiar touch. "I will put aside my own plans to see him destroyed. I am not so petty Natsu that I will leave you to fight this monster alone."

Natsu didn't know what to say…..he didn't quite believe it.

Zeref sighed. "Natsu," he said solemnly, "I made an oath to a Celestial Mage and the Fire Dragon King that I would do everything in my power to end Acnologia. It is not something I can break. You don't break promises to Celestial Mages."

That, Natsu could almost trust, after all….Celestial Mages don't break their promises either.

"I made an alliance with Igneel, the Fire Dragon King, and Anna Heartfilla, to kill Acnologia," Zeref's dark eyes bore into him," don't make me break my word. Don't break Igneel's word. Stand up, take my hand," he held out his long, pale, slim hand, "and together let's join forces with Lucy Heartfilla and finish this for good." Natsu stared at the hand waiting for it to do slap him or summon some dark magic or anything. He didn't trust this. He didn't believe this…. "Natsu!" Zeref snapped impatiently. "This won't work if it is just one or two of us, all three of us need to do this, are you not going to follow your father's footsteps in order to save the world?"

What was the point in saving the world if Zeref was going to annihilate it anyway? But then…but…..if Zeref was being good now, could there be some sort of hope?

Natsu's head really hurts now.

He took Zeref's hand. "For Igneel!" he choked out. "And for Lucy, but never for you!" he added with a snarl.

Zeref pulled him to his feet and into an awkward, one-armed, hug. There was a flash and suddenly Natsu felt better, stronger, and more powerful than ever before. The little snap of that hateful book of Zeref's was enough to tell Natsu what exactly healed him.

"I don't expect anything less," Zeref said sadly, "and I hope you know that once Acnologia is nothing but ash and dust, I will go back to my plans to annihilate the world."

"I don't expect anything less," Natsu mocked him.

Zeref's lips twitched ever so slightly. "Now then, little brother," he said in a very dangerously soft voice, "let's help your beautiful lady in slaying this Dragon. Prove to me that your education was not entirely wasted."

Natsu smirked. "I'm all fired up!"

And together they ran into battle as brother in arms, side by side, in a united front….

Pity it won't last forever.