A/N: Devil Dogger is a large species of fierce Canines that humans have bred for transportation purposes due to their ability to run quickly for long distances, much like the horse. They're intelligent but stubborn and have been known to occasionally attack their riders. Humans put up with this behaviour because, much like a hound, the Doggers can be trained to follow smells. Their primary use is criminal apprehension, though some nobles have been known to breed and ride the beasts.

^^^ so nerdy, I know; also, totally not belonging to the FT universe. Sorry!

He didn't expect to think about her after she was gone from his sight. Nor did he expect the way his fingertips burned and his tongue seared and the way his mind kept conjuring the scene again. At first he thought she haunted him because she had been so innocent and pure, especially for a human, but then she had taken his mark and worn it so effortlessly and he knew that it was something else entirely. He couldn't stop thinking about her not for what she was, but for what she was willing to become. He too had made a similar sacrifice for the brother he loved. When he looked into Lucy Heartfilia's now onyx eyes, he saw a kindred spirit. It was because of that he longed to see her again.

The longing was that of the painful kind.

The need to see her was such a strong sensation that he denied himself that pleasure. Besides, didn't she at least deserve a chance to try to pull away from the darkness? With him by her side, she certainly wouldn't; already she wanted to be his. A lamb to the slaughter. The best part of it all was that if he let her, she'd revel in it right up until the moment she breathed her last. She would walk away from everything she had ever known or fought so hard to protect so she could sit beside a dark king, if only he asked.

He tasted her on his lips again and nearly gave in to his desire. What should he care if he took her from her life? He was Zeref, the black wizard. People whispered his name beside the words terror and suffering. When it was done, no one, except perhaps Natsu, would be foolish enough to come after her. And if he succeeded? But by then, she wouldn't want to go back to the way things were, nor would she be able to.

Desperate to outpace those alluring thoughts, he hurried his steps. I made a promise, and that should mean something. There was still honour available to him, wasn't there? His existence hadn't become quite as wretched as that. Yet, it was difficult to escape the part of himself that yearned to break such bright and beautiful things. It was his curse.

Tearing into the canyon, Natsu found her limp form immediately. Face down on the too-warm and too-hard ground, her skirt was twisted around her legs and her shirt was bunched to expose a small expanse of her lower back. The visible skin looked ashen, as if she didn't have enough oxygen. She looked dead. Her horse certainly was—no living beast ever lay so still, and the air was thick with its blood. Terror lanced through the dragon slayer.

Before the Devil Dogger he'd wrangled from a breeder came to a full stop, he abandoned its back, choosing his feet to carry him to her side instead. In his carelessness, the dog-like creature snapped its fanged maw at his elbow, grazing the skin there. It didn't draw blood—that might have been a bad thing, for Doggers were known to fall into blood frenzies at the slightest provocation, though it hurt like a sonofabitch. Ignoring that and the danger he'd narrowly avoided, he scrambled to Lucy's side.

Though he did his best to keep himself calm while he turned her over, he was less gentle than he could have been, too nervous by half for niceties. Rolled onto her back, she was completely lifeless, blonde locks, so dusted with grit and grime, falling over her closed eyes. Hands shaking, Natsu pushed back her hair so he could see her face. Her lips were blue and the faint veins around the corners of her eyes were dark.

"Lucy?" Her name came out of his mouth like a squeak. She didn't respond so he shook her. With that motion, her lips parted and Natsu was hit with a smell: Zeref. Barely thinking, he clenched his hands into fists so tight that his bones creaked. Flames leapt to his palms, hot and familiar. Lifting his gaze from Lucy's prone body, he searched the area for the intruder.

There was no one there.

A sharp intake of breath had him turning back to Lucy. Before his eyes, the colour returned to her skin, the darkness around her eyes fading. Something strong pulsed through the air. Dark, coiling magic. It was gone before he could rightly place its source. Then Lucy opened her tawny-coloured eyes and he forgot to care. The fire coating his hands faded; his fingers itched in its absence.

"Natsu?" Her voice was weak, uncertain.

Natsu had a strong and sudden urge to hug her. He refrained. She obviously hadn't been dead, so he shouldn't be such a baby, right? "Lucy! Are you okay?"

"Yeah... I… I guess. What are you doing here?" She rubbed her forehead, confused.

The urge to throttle her was less easy to ignore. "What were you thinking, coming out here on your own?"

She lifted her eyes to his, her expression suddenly intense. "Did it work?"

Something dark skirted behind her eyes quickly; Natsu dismissed it as a trick of the light. "Did what work?"

She didn't bother explaining, she only had to look to the sky to see that it was gradually losing its violent hue. Shadow Father was dead, the world was going back to the way it had been, and for now she was Lucy Heartfilia, though she felt her other self waiting patiently inside. She knew that if she wanted, she could call her out. It would be an easy thing and it would feel good.

"Lucy?"

What would Natsu think of the new Lucy Heartfilia? Opening her mouth, she had every intention of telling him about Shadow Father. Then she snapped it closed again. Would Natsu, loyal and unwavering Natsu, see the gray between the black and white? Would he understand why she had to do what she did? No, she didn't think so. He wouldn't understand why she had to go to Zeref, and he wouldn't understand why the black wizard had agreed to help her; she didn't fully understand herself, that was something birthed between her mother and Zeref many years before.

"Lucy," Natsu pushed again. "What happened? I saw Loke in your apartment—someone attacked him. He was hurt pretty bad. Bad enough he had to go back into the spirit world."

Lucy considered Natsu's words. Imagine that Loke had returned to Earthland so soon? He was definitely her most powerful spirit; she'd underestimated him.

Natsu kept on talking. "Before he left, he told me you made some kind of deal and were coming here to kill Shadow Father." The words tumbled out. He was nervous.

"Yes."

Natsu's heart beat faster. "Where is he?"

"He's dead."

Natsu felt the blood leaving his face. "Who killed him?"

For a moment, Lucy was insulted. Was it so unbelievable that she could do it? It was hard to swallow, but she choked back that pride; pride wrought darkness and she needed to be wary if she were to keep her secret; the magic in her body was hungry for any scrap of gloom she'd throw it.

When Natsu glared at her impatiently, she reminded herself that she needed to answer his question. "Z-Zeref." That wasn't a complete lie. All the best ones were told with hints of truth; the more truthful, the better the lie. Zeref had given her the means to kill the beast, even if he hadn't performed the task himself.

Natsu's fists were flaming again, Loke forgotten, at least for the time being. "I thought I smelled him here. Where is the bastard now?"

Lucy thanked her good fortune Natsu was so scatter brained sometimes. "He's gone. He left when the demon died." Or shortly thereafter. Semantics.

He eyed her suspiciously. "He just left?"

She nodded.

Natsu scowled. "You're lying to me." He could smell her discomfort.

Lucy's neck heated. Was she caught?

"If he just left, then why did I find you passed out on the ground?" His eyes got fierce. "Did he attack you?"

That's what he thinks I'm lying about? She almost laughed. ...Maybe he wasn't as keen as she thought he was. She lied again, more adept than she ever thought possible. "When—when Shadow Father died there was a—a miasma or something." That was believable, wasn't it? "It knocked me out." She waited for Natsu to disprove her words.

Natsu considered her carefully. Of course, there was no reason not to trust her, Lucy had never lied to him before, but there was an uneasiness about her that was slowly leeching into him, too.

"Come on, I just want to get out of here," Lucy said to distract him. "This place gives me the creeps." That was something her old self would say, right? In truth, this place made her feel strong, full as it was with so many dark secrets. There were shadows here that wanted to wrap around her tight as a lover. She pulled that feeling in close to her heart and held it there, wanting to remember the way the power felt when she let it loose. It was absolute, that magic. Nothing could stand in her way when she wielded it. To use it again… she'd do almost anything. It throbbed under her skin like a heartbeat. All she had to do was let go.

No. You'll hurt Natsu if you do, and he's your best friend. You can't. She wrestled the power back into place.

Again, Natsu studied her closely. She looked different, almost vibrant, but not. He couldn't place it. Unwittingly drawn in by an unknown force, he leaned into her and closed his eyes. Her scent had changed, became dark and rich, utterly different, though not unpleasant.

"Natsu?"

"Mmhm?"

"What do you think you're doing?"

Opening his eyes, he saw that he was just inches from her jawline, snuffing her like some kind of animal. He startled back, skin crawling. When he wasn't so near, that clandestine richness seemed to seep from her body and Lucy was Lucy once more. Or maybe it had never been there at all.

Lucy, feeling anxious, rose unsteadily to her feet. "I thought we were going home, not sniffing me." Did he smell Zeref on her skin? Who knew, with that nose?

He at least had the decency to flush with shame. "Sorry."

"Alright, that's fine—you're weird, I get it," she said with forced lightness. "But really, this place freaks me out." It was too easy to want to call up that blackness here. If she wanted to go back to the way things were, or at least try to, she had to resist the urge to use Zeref's magic or to think about him in any way. The best way to do that was to gain some distance.

"Alright." Natsu's neck still felt hot. He turned his gaze towards the horse and that brought him back to reality. "We'll send someone back for that."

Lucy looked over to where the beast had died of fright. She didn't feel the pang of sadness she expected, just a hint of numbness.

"What happened to it?" Natsu asked, then wondered if maybe he shouldn't have. Maybe she didn't want to talk about it.

Lucy shrugged serenely. "I don't remember."

Distance didn't make it easier. Her very blood itched, and the longer she was away from Zeref, the worse it became.

Two full days passed, both of which she'd spent locked inside her apartment. On the first, Natsu tried to come over, thinking maybe she'd want some company. She'd yelled louder than ever and sent him on his way. After that, the dragon slayer and cat duo left her to her own devices, thinking maybe she just needed some time. Then the third day came and went, and Natsu had enough.

Shamelessly, he climbed up her wall and slid into her window. It was as dark inside as it was out. On her coffee table, only a single candle burned, its flame dancing and throwing the apartment's interior into flickering shadow.

Natsu waited and waited for the yelling to begin. When he heard nothing, he let some of the tension drop out of his shoulders and searched for her.

By the pale candlelight, he noted her bedroom was tidier than it had been the last time he was there, though it was still a mess by Lucy standards. Clothes were thrown over the backs of chairs, and papers were still everywhere, only now they were in scattered piles, not haphazard clumps.

Eyes coming to rest on an armchair in the center of the room, he found Lucy. Wearing an expression that was both prickly and bored—something it seemed only she could master—she was sprawled over the over-stuffed fabric, arms and legs spread widely. On her body she wore only a matching bra and underwear set. It was light blue.

Seeing her like that, Natsu's mouth dried up. Don't be a flake. Raising his brows, he tried for unaffected lightness. "Too good for clothes now?" He expected her to be bashful. When she didn't flush and stammer, just met his eyes evenly, like she wanted him to see her like this, he became suddenly uncomfortable and kept his gaze trained firmly on her face.

Lucy finally spoke. "Everything is too..." She motioned vaguely to her body and didn't bother finishing. Everything felt too tight on her hot skin. She didn't have enough space to breathe.

"Alright." Natsu let out a breath he didn't know he was holding, glad that she was at least talking. Trying for some more normalcy, he asked, "Aren't you going to yell at me for breaking into your room?"

Lucy looked at him in exasperation. "If you already know you've done something wrong, why do you need me to say it?"

He flinched. She was always tetchy when he invaded her privacy, but there were rules to their relationship. He was supposed to sneak in, she was supposed to yell at him, then he and Happy were supposed to laugh it off; Lucy would cool down and forgive them. Then they'd do it all again. But now Lucy was just sitting stone-faced and serious, her replies gouging him to the bone.

Seeing his discomfort, Lucy made her expression soften. "Sorry, Natsu, I've just been..."

When she didn't finish, Natsu asked gently, "What's wrong with you, Lucy? You haven't been acting like yourself since—"

She cut him off, unable to talk about it without thinking about him and that would only make her borrowed magic all that more irritable. "I'm fine. I just needed some time to rest. Loke's been healing, you know, and it's used a lot of my magic energy, and I'm tired—"

"Alright," he cut in. "You're right. I'm sorry."

She felt the tiniest pang of guilt but not enough to take back her words. "Thanks for checking up on me. I was just about to go to bed."

"Oh." He didn't know what to think; Lucy was throwing him totally off kilter. "I guess I'll just..."

Her eyes gleamed darkly in the candlelight, twin onyx stones. There was an expression on her face Natsu didn't understand, however, it made his chest tighten with nerves. "What is it?" He was afraid of her answer.

"You can stay, if you want." The words came out on their own accord; though once they were put forward, she had to admit that it would be good to gain some distraction from Zeref; Natsu could provide that, definitely. She knew for certain because, until very recently, Natsu had occupied every single one of her thoughts. If she gave him a chance, he could once again.

You shouldn't. it's not fair. Not fair to Natsu, not fair to herself.

She waited for him to decline. He'd say no, the moment would pass, and everything would go back to as it was.

"Okay," he said instead.

Lucy's heart sank. She wasn't strong enough to turn him away.