A/N at the end of the chapter.

Warnings: Glorious debauchery of the slash nature.

Summary: Yukio is at the end of his rope after Rin nearly kills himself in a mission, and while Rin battles with his demon blood, Yukio finds he has his own demons to deal with. Okumura Yukio x Okumura Rin. Slash content, incest, work in progress.

"Heart of Darkness"

"Rin…" Rin thought he didn't dream anymore. And it was true in a sense; he didn't see or hear or smell in his sleep, couldn't taste or feel. This was precisely the reason why he was almost stunned to tears when his father's voice pierced the black veil of sleep. It was surreal. The voice was merely a murmur at first, growing clearer and louder as he moved towards its direction. Finally, the sound became too much to simply ignore. "Rin!"

"Father!" The black exploded, expanding until everything was white and out of focus. What he saw when his vision came back was the plain gray paneling of the infirmary ward; a sleepy breeze blew in through the slightly cracked window and what he recognized as the first light of dawn, streaming in through the glass and pouring over the tile floor and his clean linen sheets. A well of panic surged in him: Kurikara! Where was it? He struggled to get up, but the intense pain that radiated from his achy chest demanded that he cease and lay down.

"Relax, brother. It's right here," Yukio tapped the sheathed sword in his lap, as though he could read thoughts. He smiled slightly as his brother visibly calmed, though he couldn't say the same for himself. Rin was so reckless and one of these days he would either get himself or someone else killed; it angered him, of course, but he also tried to understand his brother. Sometimes he blamed himself for not keeping a watchful eye on Rin, sometimes he blamed his father for spoiling him as a child, sometimes he attributed Rin's terrible attitude to Satan, but he could see now it wasn't an issue of blame. It was, simply enough, Rin that was the problem. Yukio was on the last straw; he truly didn't know how to make his brother understand the responsibilities and burdens of being an Exorcist and that he couldn't just go around charging into demons like he had last night. He sighed, placing Kurikara on the bed, "Rin, when you get better, we need to talk, alright?"

"I feel alright now…" He winced and tried to sit up, before Yukio gently pressed his shoulders back into the sheets.

"You're not alright, you lost a lot of blood last night," Yukio said as calmly as possible, his clenched fists hidden behind his back.

Predictably, Rin snorted and inched himself upright again, "I said I was fine! I heal fast and all that…" His voice trailed off when his noticed Yukio's face, "Is something wrong?"

"Yes," he replied, his quiet, conserved answer betrayed the irritation that flickered briefly upon his features, "Which is why I'll talk to you later. Just stay in bed for now." Yukio ignored the ensuring protests, closing the infirmary door behind him. The ward was quiet at this time of day, the patients and nurses alike slept. He glanced down at his watch. Five 'o clock already… with a grim face, he realized he had been up all day yesterday on the mission with Rin and then all night watching and tending to his wounds. Massaging his eyes, he slumped down on a bench, feeling drained and exhausted. Sleep, he thought dreamily, curling up in his seat.

He didn't know how long it had been, but judging by the fact the hall was brightly lit and the ward nurses were scurrying back and forth, he guessed it must have been seven or eight 'o clock in the morning now.

"Mreow," Kuro whined, nipping at the hand that dangled over the edge of the bench. It purred contentedly when Yukio scratched it behind the ears, preening and stretching delightfully at the fingers.

At least the cat appreciated him. Willing himself up, Yukio worked out the kinks in his back before standing to knock on Rin's door. Kuro followed at his heels curiously. "Rin, are you up yet?"

"Uh, yeah. Come in," Rin's voice was muffled. Yukio took a deep breath, opened the door, and peered in. The room was still bright, although the blinds had been partially closed, and a tray of food lay discarded by the end of the bed. Good, at least Rin at eaten. Yukio thought he was going to go crazy when his gaze finally landed on Rin, who seemed to be gingerly putting his clothes on. It was obvious to anyone that the demon boy was hurt, his countenance screwing up in pain every time his hand brushed a tender spot. But despite that, Rin kept trying to tug his t-shirt on, struggling futilely with the sleeves.

"Rin," he said sharply, "I said you needed to stay in bed. You'll rip your stitches like that." He closed the door behind him and moved to where his brother's face was still obscured by the clothing. Yukio ripped the shirt away from him, eyes hard, "Why won't you just listen to me? I'm telling you this because I care."

Rin blinked at him, confused, "I can't stay like this knowing the bastard ghoul that did this to me is – "

"Listen to me," Yukio hissed and snatched the pair of pants that Rin was reaching for, "Demon or not, your lungs almost collapsed. If you exert yourself, you are going to die. Do you understand, Rin?"

"Don't talk to me like I'm a child!"

"Then quit acting like one."

"I'm not - don't tell me what I am!"

"Rin," he sighed, "even you don't know what you are. Half the time, you don't even know what to do with simple class assignments. So please, just lay down for a bit!"

"Don't tell me what to do, you're not my father!" Rin snapped heatedly, but he immediately regretted his words. Yukio stared at him, his gaze cold and his jaw set stiff. Kuro cowered, slinking away to the window. He was just so angry; his brother always treated him like he was stupid or simple, like he was a child to be watched over even though he was the older of the two. Sometimes he wished it were the old days when it was him protecting Yukio and not the other way around. But it was also wrong of him to bring up their father. Rin knew it was an especially sore spot for Yukio, not to mention for himself, "Sorry, look, I just – "

"No, it's fine," Yukio calmly folded the slacks and put them neatly on the drawer by the bed, "You're right. I'm not our father, because our father isn't here anymore. And you know what? He would be rolling over in his grave right now if he knew you were throwing yourself idiotically into danger all the time. Do you know…" he said, aggravated, "… exactly the lengths he went to just to protect you?"

The regret turned into blinding anger instantly. How dare Yukio try to guilt him? "Then go away! I never asked you to help me, Yukio. I know he protected me, but he's gone now, so I have to protect myself. If you feel like it's a burden, then just stop – I don't need you!"

Smack, the resounding slap echoed off the empty walls. Yukio stood over his brother, shaking with fury. Rin stared at him, features glazed with shock; slowly, he reached a hand up to cradle his cheek. Tears threatened to spill, and he looked away ashamedly. This was the first time in his life that Yukio had hit him. For as long as he had lived, his younger brother was always mild-tempered and kind, but he seemed like a completely different person at the moment.

"Who said it was about me?" He said lowly, "Or even you, brother?" Yukio grasped his chin in a deceptively gentle hold, "It's about dad, who gave almost his entire life, to raise you as a human so that you could be safe. Yet you denied him his dying wish and unsealed Kurikara, then you wanted to be an Exorcist," he jerked Rin closer, "and now you can't even take care of the life that he sacrificed his own to keep alive. You are a burden, Rin – but not to me… to father."

Rin withdrew himself from the touch hastily, silent with uneasiness.

"Oh, Rin? Your bandages need changing. Are you going to do that by yourself too?" Yukio pointed to the wrappings; some had come undone and others were beginning to soak through with blood. Rin clenched his jaw in determination. If his brother thought he was a burden, he would just carry himself. Yukio's voice breached his thoughts a second time, "Then again, I always did this, right? You would just go out and get yourself hurt, and I'd do all the cleaning up. Here…" Yukio reached over to peel away a piece of gauze.

Rin pushed away his hands with ease, "I'll do it myself," he muttered. Yukio only watched smugly as Rin struggled with the cloth, awkwardly trying to pull them off without taking some skin off where the blood had dried the bandage and flesh together. He hissed in pain as he removed a strip of gauze from a particularly tender area. Rin sighed, conceding defeat. "Fine," he said and let his arms rest at his side while his feet dangled awkwardly off the ground.

Yukio crouched by the bed to survey the wounds. "Some salve will help the bandages come off," he murmured, reaching into the bedside drawer. Rin watched his brother uncap the tin with wary eyes and said nothing when his arms were moved out of the way.

"Maybe I do need him," Rin sulked. He wanted to become an Exorcist so he could shoulder his own burden, but now he was only creating a burden for Yukio. Had he been a burden to his father as well? The demon shivered as Yukio brushed a slippery finger across his nipples. He glanced down at his brother guiltily, but Yukio hadn't noticed anything, so he quickly looked away towards the window to keep his blush shadowed. The younger twin continued smoothing salve onto heated skin; Yukio had known since childhood that his brother was attractive. And it was true that if Rin had a better attitude, he would be plenty popular with girls. As for himself, he never truly felt jealous of his brother, but rather he coveted Rin's beauty. It would be him who would protect his older brother – no one else.

"Rin, I'm sorry… about hitting you," Yukio cupped his cheek gently, "I was just really angry and I don't know what came over me. Will you forgive me?"

Rin regarded Yukio silently before pulling him into a warm embrace and grumbled, "Bastard, of course I will. Brothers don't fight brothers. They're family." Yukio smiled; this was how it should be. The demon brother quickly pried himself out of the hug; Yukio was confused and opened his mouth to ask what was wrong, but Rin cut him off stiffly, "So yeah, just wrap me up so I can go," he turned his face away from Yukio. The younger brother raised an eyebrow in exasperation, but did as he was told. Rin let out the shaky sigh he was holding; it was a bad idea to hug Yukio… his brother's warm breath on his bare shoulders, the way he was pressed up to Rin's belly sent heat to his groin (and the rest basically went to his face). What the hell am I? A sick freak? A sick incestuous freak, his mind concluded unhelpfully. It was definitely something taboo in his household, even if he and Fujimoto played a little fast and loose with Catholicism, and especially taboo because they never spoke about it. He concluded there had to be a reason why it was never brought up, even in his religious studies.

Relax, he told himself. It was probably a biological thing; everything at this age was supposed to give him a hard-on at the drop of a pin, right? Rin gaped as Yukio moved almost on top of him to reach the roll of bandages on the bed behind him. Crap, please don't feel that. Please do not feel – his mind reeled in panic as Yukio froze against him.

"Ah, got it," Yukio withdrew cheerfully, holding up the gauze. Rin blinked, relief flooding his tensed muscles. He dodged the bullet on that one.

With the bandages secured tightly around his chest, he could finally breathe again. It drove him crazy every time his brother touched his skin, and he didn't even know when this feeling started. "Thanks," he said, smiling softly.

"That's what brothers are for, right? Look, about the ghoul, I promise you that as soon as you're better, we'll track him down," Yukio patted him on the head, "And then you can 'kick his ass', alright? Until you're better, please don't strain yourself."

"Yeah, yeah - I got it," Rin slid the covers away, "But when can I leave this place? Gives me the fucking creeps."

Yukio paused at the door, "You could come back to our dorm room now," he looked at the watch on his wrist, "If you want, I can help you there now, but we need to hurry. I have classes soon."

"Sure," he began to push the covers back but realized the thin cotton infirmary pants he was wearing would most definitely make an erection obvious, especially now that he would be upright and walking, "Er…"

"What's wrong, brother?" he asked impatiently. Oh, Yukio knew what was wrong. He knew exactly what was wrong, and he had known it for a while. He had his doubts at first, but it all made sense when he thought about it. Rin didn't have many other friends, and except for the few that accepted him here, Yukio was his brother's only true friend, so to speak. Yukio loved his brother and wanted to protect him, but sometimes Rin drove him crazy… and while at first he rejected the thought, it didn't seem like such a bad idea after his outburst. There were, the thoughts went, certainly other ways Yukio could 'punish' him for misbehavior without ever having to lay a hand on him again. It was sort of satisfying, as haltingly as he would admit it, to see his regularly stubborn older brother squirm uncomfortably, but he didn't want to be schadenfreude about the whole deal either. Wrath was one of the seven deadly sins, he reminded himself. Then again, hadn't Rin already fallen to lust? He watched with carefully concealed amusement; Rin tried to get up with the blanket in his lap and his face was completely flushed as he grabbed Kurikara.

"I mean it. Thanks," Rin said quietly, almost too quiet to hear. Yukio hummed in approval held out a steady hand, which he took gratefully. Besides the huge gash across his chest, the rest of him was littered with small (but painful) scratches and bruises from the tumble he took through some brush after the ghoul had flung him back. It wasn't a long trek from the infirmary to their rooms, thankfully enough, and though it was almost time for classes to begin, the quad was relatively quiet save for the twittering of some birds.

Yukio helped his brother to his bunk, "If you need anything, just call me," he handed Rin his phone, which had miraculously survived their mountain trip and the ghoul attack. He turned to put the lights out, scanning the bed with a sense of finality. At last, he could finally rest easy. As he closed the door to their dorm room, a loud 'ahem' brought his attention to the slender woman leaning by the frame.

"Yukio, is he…?" she trailed off. Besides the worrying glint in her eyes, she seemed to be exactly as she was before they'd left.

"He's fine for now. Thank you for your concern," he answered amiably, though within, he felt tired and irritated – he just wanted to start class on some bookwork and perhaps slip away for a bit to nap. Speaking of classes… "Don't you have class now, Professor Shura?" He enunciated the title for extra measure.

"Huh… yeah, yer right," she scratched her head sheepishly, "I just wanted to pop in on Rin really quick…"

"Shall I walk you then?"

Shura shrugged, "Yeah, sure."

Their conversation died down as they reached the quiet sanctuary that was True Cross Academy, whose halls were devoid of any students, as they most probably would've waited in their classroom seats. Shura stopped in front of an ornate heavy oak door, which Yukio observed must be her class. She ruffled his hair lightly, without the usual energy, "Remember what I said about hiding your true feelings? Bottling them up will just hurt you, so if you need to talk…"

"I know," he said flatly, "Trust me, I know." She looked at him mournfully again before slipping inside. Yukio started class without incident, the students apparently not involved enough to ask about Rin, but throughout the day, he couldn't help but keep a hand over his heart like somehow his hand would keep the darkness away.

Most people didn't know or remember how a demon possessed them, because demons, like darkness crept up on humans like a shadow, absorbing space in the heart until finally it had the strength to take the entire body. It was nearly impossible to predict that a demon was planning to possess, and the only indication would be darkness, a blanket word for human feelings like regret or hate or sorrow that allowed demons to come to Assiah. The more introverted, the more morose, the more a person holds themselves back, the more those feelings dig into their soul, leaving deep gouges for darkness to fill in. And Yukio knew this. He knew this better than anyone, because he struggled with it more than anyone.

"I hit Rin," he admitted bitterly, "But far worse than that? I almost planned to exploit his… feelings for me." He sunk into his seat, smiling pleasantly at the class, but in his head, he could only chant, "God save me…"

A/N: I'd really love to see this series flourish more than anything! I think Yukio is really good at hiding his emotions, so the reason why he seemed so nice to Rin after their fight was really just him covering up his frustration. (Wouldn't you be frustrated too with a stubborn brother like Rin?) It's rated mature because things will escalate in later chapters; I just feel that to keep the two as in-character as possible, there's some building to do... as much as I love PWPs. What I'm feeling with this story right now is something more Yukio-centric; the "Heart of Darkness" title is a reference to him. Anyways, reviews are truly encouraging, so please don't hesitant to critique or comment.