STA: It was already written by the time I posted the last chapter, and I promised on tumblr that I'd get this one up fast, so here you go.

-x-

"It's chronic."

"Like time magic?"

Porlyusica shook her head. "A chronic illness. It doesn't go away."

Natsu scowled at her. "I'm not sick though. I don't have a fever. It's just that I get tired. Ever since that time I was hit in the head, I've gotten tired easy."

"Is that when it started?" she asked. "I've never heard of a case of Suraci's Disease starting so late in life, but from what I've read, children who don't exhibit symptoms at birth usually have them come on gradually. Your injury was less than three weeks ago. The accounts I've found describe it as taking months between when patients notice anything and then the first attack hits. Sometimes as much as a year."

"I was fine before then," Natsu insisted. "It's only since the injury that I get tired easily. What do you mean it doesn't go away? I can still fight, right?"

Ignoring the questions, Porlyusica asked, "Was it the injury that caused your fatigue, or did fatigue lead to the injury?"

"I didn't get hurt because I was tired. I got a headache, and that monster took advantage of it to attack me."

"A headache like the one that knocked you out yesterday?"

"W-well… yeah." Natsu looked away. "But I can still fight, right?"

Porlyusica hesitated before saying "The disease is usually apparent at birth, and infants can't survive more than a few weeks with it. Older children developing it is rare—unheard of, at your age—and there haven't been many effort to make a drug for it, but treatments exist. There are other options that people have found. Herbal remedies that help keep up one's energy, and exercises. Therapy that can slow the disease's progression. Maybe even reverse some of the damage."

"I don't have a temperature," Natsu insisted. "I'm not any warmer than normal. And I haven't been around any sick people either."

"It's genetic," Porlyusica told him. "You were born with it. It's not a matter of catching it from anyone. You've always had Suraci's, and it was just a matter of time before it took effect. It's strange for you to develop it so late. I wonder what stalled it? Or maybe the gene responsible for the condition was inactive, and something triggered it?"

Natsu scowled at that. Obviously he had no idea why he'd developed the disease now, much less why the it didn't kill him as a baby, but Porlyusica had said that not everyone developed it then, so that didn't really matter. And regardless of how or why this problem had emerged when it did…

"What remedies am I supposed to use to cure it?"

"It's chronic. You can't cure… Oh, forget it. I'll write up a recipe for you. The herbs are easy to purchase over the counter, and it doesn't take much effort to brew them into a tea. You'll want to take it first thing in the morning. If you feel weak at any other point throughout the day, have another cup. Don't take any after dinner. It's important that those with Suraci's Disease be well rested, and the brew can disturb your sleep schedule if you have it too late in the day."

"And if I take this tea, I'll get better?"

Porlyusica sighed. "In a sense, yes. So long as you properly maintain the condition, you can reverse some of the damage done by Suraci's. But Natsu, when you have an attack like the one you suffered yesterday, the disease advances. You need to pay close attention to your symptoms. I know you've always pushed yourself well beyond your limit before, but attempting that now will only make you weaker."

Natsu didn't respond, so she folded her arms and leaned back, watching him, waiting for some acknowledgement. It was an important enough point that she refused to leave until she had confirmation that he'd heard.

It took a few minutes of waiting in silence before Natsu turned back to face her and, after another minute, met her eye. "Don't push myself," he repeated.

"Because of the attack yesterday, you might feel weaker for the next few days. The tea will help. I'll brew some for you in a minute. And I'll give you a set of exercises to do that will help you maintain a reasonable level of physical ability without exhausting yourself. Don't resist help. The last thing we want is for you to suffer another attack attempting something that a friend could have done for you. Understand?"

Natsu clenched his fists, imagining himself sitting obediently while Gray or Gajeel or Laxus did something simple for him, laughing about how easy it was. Or worse, pretending it was no big deal that they had to do it for him when it really was easy.

But then he imagined himself sitting around the guild forever while everyone else was able to run off on jobs and help in fights. He could suffer through a little acting helpless if it meant he could get back to work after.

"Understood."

-o-

Porlyusica set to brewing tea in the guild's kitchen, and while she waited for the tea to finish, wrote down her instructions and recipe for Natsu.

Most of the ingredients were cheap, but one of the spices cost a bit more. It occurred to her as she estimated the cost of the tea she was recommending him that fighting was how he made his living, and that it was highly unlikely he would be fighting again before the years end. Not if he was serious about managing his condition, at least. Maybe never, depending on the severity of the previous day's attack. Probably never, and certainly not at the level he used to.

She was straining the tea when Makarov stepped into the kitchen, and waited for him to shoo Mira away and shut the door.

"He isn't dying, if that's what you're about to ask."

Makarov's shoulders sagged in relief. "So it's nothing to worry about."

"I never said that." She hadn't realized she brewed so much tea at once, and began searching the cabinets for a jar to store the excess in. It would be good to have some on hand at the guild. "I would advise you take him off active duty, and make sure his team knows he isn't to take jobs with them. Not unless I say he's fit for work again. If he needs money, have him work here. Give him something simple. Record keeping, perhaps."

She paused after saying that, and they both looked at one another in disbelief, knowing that there was hardly a worse task for Natsu to be in charge of.

"How serious is this?"

"It's Suraci's Disease. It causes deterioration of one's strength and senses. If he isn't mindful of his condition, he'll get weaker. And an attack like yesterday's can permanently damage his sight or hearing, if he has a particularly bad one. I've never heard of anyone with the disease managing to learn magic before they fall ill, but I would expect it hinders that as well. In advanced cases, patients become too weak to take care of themselves. Can't support themselves well enough to stand. I've even heard of incidents where senses begin to shut down completely. So take the idiot boy off active duty before he triggers another attack."

Makarov grimaced. More than anyone else in the guild, Natsu loved to be in on the action. To fight. A condition that sidelined him permanently would be heart breaking. "You can't do anything to cure it? Suppress it?"

Porlyusica sighed and shook her head. "If caught early enough, before the first attack, it can be managed with little difficulty. There are records of people diagnosed with it who go their whole lives without any inconvenience from their condition beyond that they need to keep up treatment."

She'd shaken her head, but Makarov held on to hope. "Did we catch it in time?"

"No." She scowled at him, knowing that he knew Natsu had suffered an attack only the day before. "By his account, it sounds like this was the second attack he's suffered, which means we're starting treatment for him later than most. We didn't notice the first because he took an injury in battle immediately after."

She found the jar she was looking for, and slammed it down onto the counter. The glass base cracked from the force, and she stared stupidly at it a moment before resuming her search.

"Then I'm surprised anyone can discover this in time to treat it," Makarov muttered.

"It's not hard. Not if the patient reports it when they feel something off. Natsu likely noticed something, but dismissed it. He didn't tell us about the first attack, after all. That's no fault of his own, really. The ones who catch the disease in time have the luxury of knowing their family's medical history."

Behind an old, rusting Dutch oven, she found another suitable jar. It was collecting dust, so she turned the sink faucet on and grabbed soap to wash with.

Makarov watched her clear the jar, then pour a sharp scented tea into it. It was rare for Porylusica to make any of her remedies on site, and to see her do so now made the hairs on the back of his neck stand up. But she said Natsu wasn't dying. What other urgent reason could she have for making something for him then and there, rather than returning to the comfort of her own, nearby home to do her work?

He didn't need to ask. She grabbed one last ingredient to add to the tea that wasn't being stored, and handed Makarov a mug of her brew. "Keep an eye on that boy. He worries me. I don't trust him to take his condition seriously. And make sure he drinks all of that. It will help him feel better, and reduce the likelihood of another attack while he recovers from this last one. I would like to give him something stronger, but Suraci's isn't a common condition by any means. Nothing in my books mention a more effective mixture, and I haven't heard of any groups developing a medicine that treats the symptoms more efficiently. He'll have to make do with this."

"The concoction you put in the fridge… Should he always have that around noon?"

"If he asks for it, bring him some. And make sure to warm it first," It didn't need to be served warm, but Natsu would likely learn fast that it tasted better that way. And the less incentive he had to use his magic, the better. "I suppose I should make a copy of the recipe for you as well?"

She looked to the papers. She'd already written down a fair amount, and she wanted to get back to her home already.

Makarov followed her gaze, and reached up onto the counter to grab the instructions. "I'll have Erza copy the recipe. Thank you for coming out as soon as he woke up."

"You say that as if I was here fast enough."

He had no good reply to that, and rather than acknowledge that they hadn't acted in time, focused his attention on the papers she'd written up. There were exercises, he noticed. Things Natsu was supposed to do to help keep recover strength he might have lost without wearing himself down. Good. That would give him some goal to work towards. Although… Natsu would have the good sense to only do as much as instructed, right? Makarov worried that given the chance, Natsu might do more than Porlusica's instructions said, thinking that doing twice the work each day might halve his recovery time.

Porlyusica must have glared the rest of the guild into submission and avoided questions as she left, because when Makarov stepped out of the kitchen, a barrage of questions exploded from everyone in the room. Was Natsu going to be okay? What sort of virus did he have? When would they be able to go on jobs with him again? How serious was the situation?

Makarov shut his eyes and tried to tune the noise out. He couldn't blame them for worrying. It had alarmed them all when Natsu's team had burst into the guild hall the evening before, Gray caring an unresponsive Natsu in his arms. By the ice mage's account, he'd collapsed without warning, despite no one having struck him. Makarov inspected him for curses, and Wendy had checked for any diseases. She found that something she was completely unfamiliar with was wrong, but what exactly it was and how to fix it had been beyond her.

Porlyusica had been summoned then and there, but until Natsu woke, she said, she couldn't tell any more than Wendy had.

He opened his eyes and searched the crowd for Erza, spotting her in a back corner of the room. As the one who'd told Natsu to separate from her and fight while he was in less than perfect condition, she had taken the blame for his collapsing on herself. Considering that Natsu had apparently been hiding his health issues for some time, Makarov hoped she could realize sooner or later that she'd done nothing wrong with what knowledge she had.

"Erza." She looked up at him, and he held the papers above his head so she could see them. "Copy these. Give the recipe to Mira. Keep the exercises on your…" Erza might encourage Natsu to work more than he should. "Give the exercises to Gray."

He couldn't think of anyone closer who would not only definitely tell Natsu when enough was enough, but also force him to stop if need be.

"Yes, Master."

The crowd parted for her without needing to be told, and she took the papers from him.

"How is Natsu?" She asked before turning away.

"Sick," Makarov responded. "He'll have to go off active duty for some time."

"I see."

Mercifully, she left it at that. The questions from the rest of the guild resumed, but a sharp glare from her silenced them.

Thanking her mentally, Makarov made his way across the room to the infirmary.

Inside, he found Natsu staring at his hand, flexing and relaxing his fingers, then stretching them back slowly. The dragon slayer didn't so much as glance up when the guild master entered.

"Is your hand bothering you?"

"There's been a few times lately where I thought I threw a good punch, and no one even flinched," Natsu told him. "Is that the tea the old lady mentioned? It smells nice."

It was a moldy color between green and brown, and the scent was too sharp for Makarov's tastes, but it was good if Natsu liked it. He would be drinking it often, and for a long time.

He offered the tea up for Natsu, who took it and drank with no further prompting. He set the glass by his feet when done, then stood slowly, sat, and rose to his feet faster.

"There." He grinned. "The way the old lady was talking, she had me scared."

Porlyusica had been right to worry about how he'd handle his condition.

Clearing his throat, Makarov said, "Natsu, I've decided to take you off active duty."

"Oh…" He blinked. "Well… alright. Last time my head started hurting I didn't feel like I could work for a little while after anyway. When do I go back on?"

"When you've finished recovering." If, technically, but Makarov didn't want to say anything to illicit protest.

"Gotcha." Natsu glanced down at his hand, flexing it again, then turned to face the bed he'd been sitting on. Crouching down, he slid an arm under the mattress and attempted to lift it. It barely budged, and the effort made him gasp.

"Stop that!" Makarov snapped. "What are you doing?"

"Just checking," Natsu muttered. He needed to know how badly he'd been effected this time, didn't he? He didn't have that feeling that something was wrong yet, so there hadn't been any danger of triggering another attack. Why was Makarov so short with him?

They were all going to be like this, he realized. He had collapsed without warning, and now he apparently had some permanent disease that had put him in danger twice while on the job. Gray and Gajeel would probably be waiting outside the infirmary again, telling him that they could either let them walk him home, or drag him to the hospital. Wendy would constantly check up on him. Lucy wouldn't just tell him not to break things. She would tell him not to do anything.

He paled. If he'd known this would happen, he'd have let them take him to the hospital after the first attack. They were going to fret over him either way. Why had no one warned him that he might end up with some weird sickness?

"Sorry."

"For what?"

"I should have said something sooner."

"You're the one suffering for it. You don't need to apologize to me. Are you alright standing? You don't feel tired?"

"I'm fine." His stomach twisted thinking of how many times he's said that in the past month without being fine at all. But he really wasn't tired. "How many people are here right now? In the guild hall?"

"Everyone who's in town. They're worried about you."

That's what he'd been afraid of. "Can I go out the window?"

Makarov looked at the window to the infirmary. It wasn't too high off the ground, but…

"Best not. We don't want you to hurt yourself. Are you unable to face your own comrades, Natsu?"

He'd meant the words to be challenging. To rile Natsu up and make him storm out into the main guild hall, face everyone, and prove he wasn't afraid to look them in the eye. Instead, Natsu reacted by refusing to meet Makarov's eye, gaze going down to his feet.

"Natsu?"

"I could hear them just fine from here. Can you answer their questions for me?" Natsu asked.

"Are you—"

"I'm fine." The words came out more forcefully than he'd meant them too. "I don't want to answer their questions. And I don't want them telling me how not to hurt myself either. I'm staying here. I'll go home when everyone's gone."

The urge to smack Natsu and tell him to face everyone was strong, but Makarov fought it down. Facing things without hesitation was par for the course with Natsu, and if he wasn't jumping at the chance to do so, something was wrong. Of course something was wrong. He'd just been told he had a chronic illness and might not be able to fight again.

"Alright. I'll have Gray stay and walk you back."

"I don't need Gray escorting me."

"It's only temporary, Natsu. Once we're sure the walk isn't too much for you, you can come and go on your own."

-o-

Despite Makarov's words and the incessant worried whispers that Natsu had heard through the infirmary door, he still hoped he wasn't going to handled so delicately that he wouldn't be allowed to walk home on his own. He'd even sent Happy on ahead with the excuse that someone needed to get dinner started and Gray would be there to look after him.

It wasn't fair to be upset with them for worrying about his wellbeing. He tried not to look too disappointed when he finally left the infirmary after regular guild hours and found Gray was indeed waiting at the bar for him.

"How are you feeling?" Gray asked.

"They didn't kick you out before locking the place up?"

Gray held up a key. "I'm handling that tonight. I've gotta give these back to Mira tonight if I don't want to come bright and early to open the guild up for everyone too, so let's get this over with quick—Ah. I mean… let me know if we're going too fast."

He watched Natsu carefully as he attempted to repocket the keys, then, to Natsu's relief, had to look away to find where his pants had gone so he could access their pockets. Even though Gray was the one wearing absolutely nothing, Natsu felt naked under that gaze.

"You're well rested, I take it?"

"Yeah."

"Alright then." Gray stood, buckling his pants. "Let's go."

He was still missing his shirt, but he would be able to get it when he came back in the morning.

Natsu had half expected Gray to interrogate him on how he felt on the walk home, and was relieved when Gray didn't do anything more than to instruct him to speak up immediately if he felt less than perfect. Since he wasn't being grilled on a diagnosis he didn't fully understand himself, he decided to risk skirting the edge of the subject and asked a question that had been nagging at him since he woke to Porlyusica hovering over him earlier that day.

"What happened after I collapsed?"

"I carried you out of there," Gray told him. "I couldn't leave you unconscious in enemy territory. Happy told the girls what happened, and I left ahead of them. They caught up before I made it back to the guild. Not sure if they finished off our target or not." He shrugged. "I guess Erza and I might need to head back out and take care of that. Can't leave a job half done."

"And Lucy?"

"She could stay with you. Someone ought to. At least while we adjust to… this."

"I don't need people staying with me. If she wants to go out on a job, she should."

Gray paused a moment, assessing Natsu. He didn't look tired. Makarov had gone over what Porlyusica had said with him in such a way as to stress that Gray was to be on alert for even the slightest hint that Natsu wasn't feeling his best, but so far he seemed alright. Leaving him in Magnolia alone while the rest of his team resumed work felt mean, but Natsu would be off active duty for some time to come, and they couldn't skip out on jobs forever.

"We don't know what your condition is after what happened yesterday. Gramps asked me to see how well you handle the walk home," Gray decided to tell him. "If I think there's some concern with you making the trip on your own, then his orders are for one of us to stay and help until you've recovered."

Natsu growled. "Do I look like I can't walk? I'm not an invalid!"

Gray gave him a level stare, and in an obnoxiously even voice, replied, "And we'd like to keep it that way."

Huffing in indignation, Natsu stormed past him.

Gray considered telling Natsu to slow down and not wear himself out, but that might make Natsu angrier, and angry Natsu would fight him. Even if Natsu wasn't able to put up a physical fight, which Gray didn't know for sure was the case, he could resist warning to handle his condition cautiously. If Natsu felt the need, then he ought to slow down. Gray hoped.

As it was, Natsu did slow down. While it disgusted him to admit it, he felt his legs getting tired, and couldn't keep up his pace without giving away that he was wearing himself down over so little. Porlyusica had told him his strength and energy would drop thanks to his disease, but he hadn't realized she meant walking fast would take so much out of him. His legs felt like lead, and they were only half way to his place.

That was ridiculous. He spent the whole day in bed. There was no good reason for such a short walk to be tiring.

He slowed, trying to make it look less like he could no longer move fast, and more like he was giving Gray a chance to catch up. When Gray did catch up to Natsu, he slowed as well, falling in step with the roset as subtly as he could so it wouldn't be obvious that he was letting Natsu take it easy.

Natsu's house was a fifteen minute walk from the guild. It took them over half an hour to get back. When they did, Natsu let himself in, and didn't bother to invite Gray or tell him to leave. Instead, he walked straight to his couch and flopped over on it, giving his tired legs a rest.

"Finally."

Gray didn't want to bring the subject up again, but Makarov had given him a job. "Was the walk hard on you?"

It shouldn't have been, and Natsu blushed. "I don't feel weird like right before I got those headaches, so I'll be fine to go to the guild on my own and back."

"Then why the 'finally'?"

Natsu glared at him.

"I only ask because you swore you were fine last time."

That made Natsu flinch, and he looked away.

"Natsu."

"My legs are a little tired," he admitted. "I really don't feel bad. That was just…" A lot of walking. He wanted to say it was a lot of walking, but it wasn't. He walked that much every day. There was no reason for his legs to be tired. "I don't think I'm going to collapse again, walking that distance. It should be fine."

"I'm going to get sick of the word 'fine' real fast, aren't I?" Gray sighed. "I can't even tell if it has any meaning when you say it."

"Well, since I'm fine now, you can leave," Natsu growled. This was exactly what he'd wanted to avoid by leaving the guild once everyone had gone home.

"Fine. But I'll be back in the morning. If you're tired from walking that little, I don't want you going out on your own."

"I don't need an escort, Gray."

Gray scoffed and grabbed the door. Before slamming it behind him, he shot Natsu a cold, hard look and said, "Don't be a brat. We're worried for you."

-x-

STA: Technically, chronic doesn't mean life long. It just means long term. I think the specific definition is lasting more than six months. Chronic illness has a nicer ring to it than lifelong illness though, in my opinion, and many chronic conditions are lifelong, so it's not inaccurate, just imprecise.

I came up with the details of the disease prior to learning Zeref's backstory, then set the story aside in favor of another project. By the time it caught my interest again, the story behind E.N.D. was known. Originally, Natsu was only supposed to be about five or six years past the normal age of onset, with Igneel being the reason he didn't get sick earlier. After that reveal, I preferred the idea of the disease being why he died when he was little, and Zeref's tampering being what held it off for so long. Of course, since Natsu doesn't know that, it's never going to be explicitly stated. There was just some room for anyone who knew about his having died to figure out this fic's explanation for why.

Spoilers for you anime only peasants, by the way.

Daygon Yuuki: Since I reply to reviews at the end of chapters this is a little late, but yes.

Defendedclone: Ah. That's a relief. As for the Nalu thing... it isn't happening. It was intended originally, but it was swapped out in favor of Gratsu. (In this chapter, actually. At the point where Makarov asks Erza to give those papers to Gray.) The plan is to slowly give that more focus.