The room was so silent you could hear a pin drop as Lucy processed what Mavis had said. Her heart raced as tried to imagine the two boys she knew as brothers. In her mind they wouldn't fit together and she immediately discarded the idea. It had to be a different Natsu, obviously. She felt stupid for even thinking that it could be the same Natsu that she knew, but kept quiet about it, not wanting Mavis to know that she had assumed the small blonde had meant her Natsu. It was impossible. Wasn't it?

"Not our Natsu," Lucy finally managed to whisper.

Mavis looked up at her, shrugging, "I never saw the boy that Zeref called his brother, so I couldn't be sure, to be honest, but it's possible."

Lucy shook her head, "How?"

"No one really knows Natsu past and even he's admitted that the only parent he's ever known is Igneel. It could be that Zeref managed to revive the boy and somehow he ended up in Igneel's care, never knowing who he was or where he came from," Mavis suggested. "But then this is all conjecture and it could be that Natsu just lost his parents at some point when he was small and Igneel adopted him, who knows?"

Lucy thanked Mavis and the small master left, leaving Lucy to ponder the situation. If Zeref would go that far for his brother, how far would he go for the girl he loved? She shuddered at the idea, her heart clenching as she began to understand the war that was waging inside of him. How easy it must feel to fall back into his old ways and obsessively look for a way to keep her alive. She prayed that he wouldn't; he'd taken that path once and it had led him to darkness. This time she hoped that he would leave it alone and allow things to progress as they did naturally.

Zeref peaked his head in as Mavis left, studying his girlfriend carefully. She seemed so peaceful as she rested, but he still wondered how much longer she had left if she kept things up. The idea of losing her terrified him and he struggled with himself, wondering if he should try to find a way to keep her alive. He wouldn't use the R-system again, that had proven to be his undoing before, but maybe there was a way to keep her from even dying in the first place. Thoughts raced through his head as he sat beside her again, slowly piecing together what little information he knew about Lucy and her newfound magic.

"There has to be a way," He whispered, staring at the blonde he had fallen for. "I can't lose you, too."

Lucy opened one eye, looking at him curiously, "Zeref?"

He looked up, holding her hand in his, "Hey, Lucy."

"Don't you be thinking what I think you're thinking," She warned.

"I can't lose you, Lucy."

She shrugged, struggling to sit up even though it exhausted her to do even that little bit.

"Eventually you will have to, whether it be now, ten years from now, or a hundred years from now, everyone dies," She said softly.

"Not me," Zeref answered sadly. "I just keep on going even when everyone I've ever known or loved is gone, I still keep going."

Lucy smiled sadly at him, "Well, one day you'll have to quit. You can't go on forever after all."

He chuckled bitterly, "Why not? It's been four hundred years and I'm still here."

She took his hand in her own, "But I'm here now."

He smiled down at her, "Yes you are, which is why I cannot lose you."

She sighed and shook her head, wondering what she was going to have to do to convince him not to go down this road again. Before she could say a word his eyes widened and with a kiss and a promise that he would be back as soon as looked something up, he was gone. Lucy watched him go with an ache in her heart and a twist in her gut. Zeref had thought of something, she was sure. She just wasn't sure that he should be looking up whatever it was that he had thought of.

Zeref hurried toward the library, his thoughts racing. He knew that what he was thinking of doing could be construed as immoral if not illegal. He didn't care if it meant that he could save Lucy. Once he had created the R-System to revive his little brother and if he could create that then he could keep Lucy alive, right? His brain shifted into high gear as he entered the library, heading for the rare book section.

Hours later, Zeref was buried in a pile of books, scratching away on a notepad he'd dug out of the pack he had unknowingly carried with him. His hair was a mess from constantly running his fingers through it while he pondered what he scribbled on his notepad. Any time he finished a book he set it aside, carefully marking each section he needed with a small bookmark before closing it, just incase he needed to pull it out later to reference it once more.

"Zeref?" Levy appeared from around the corner, possibly carrying her weight in books.

"Hey Levy," He said with a distracted wave.

The small blunette giggled, wondering if that was how she appeared when she was doing research herself. Silently she set her books on a table not far from the mage before approaching him once more.

"Here," She handed him a pair of her Gale-Force reading glasses. "These help you read faster, so that you can absorb more."

Zeref hesitantly took them, "Don't you need them?"

She grinned, "I have an extra pair. No worries."

He smiled as he gratefully accepted them and hesitated once more before asking, "If I'm not finished when the library closes, is it possible to hold certain books?"

She nodded, grinning brightly, "Just ask the librarian to keep them on reserve for you. If you want I can reserve them with my own. I have a special relationship with this place and normally when I reserve books they'll just leave the books where I left off so that I can come back the next day and continue on without having to search for the books again."

He smiled gratefully at her, "I would appreciate that."

She grinned before waving his thanks away.

"Anyone who cares about Lu-Chan is a friend of mine," She answered.

Lucy slept as she waited for Zeref to return, slowly but steadily recovering her strength. When she finally opened her eyes again the sun was just starting to set and still there was no sign of Zeref. She sighed before turning to look at the person that was sitting beside her, giggling softly when she saw that Natsu had fallen asleep waiting for her to wake up.

"Natsu," She whispered. "What on earth would I do without you?"

He opened one eye, peering down at her, "Probably disappear."

She flushed, looking away, "Whatever."

He smiled down at her, "But I'm here, so you'll never have to worry about that. I won't let any harm come to you, Luce."

She smiled up at her best friend, warmth flooding through her.

"Thanks, Natsu."

He smiled down at her, wishing more than ever that she'd never met Zeref.