Fictober Day 10: "Listen, I can't explain it, you'll have to trust me."

Yukio was acting weird.

As usual, he was up before Rin. But what was unusual was that Yukio had almost forgotten his breakfast. Just walked right by the table, and then when Rin asked him about it, he'd only eaten a little bit before heading off to the academy. Then Rin had to bolt after him before he got too far because he'd left his lunch in the fridge.

"Oh," Yukio muttered distractedly when Rin's fingers curled around his wrist. "Right. Sorry."

Rin frowned as he immediately turned and fished in his pocket for his magic key. It was so unlike Yukio to forget things. Especially food—most of the time Rin was sure that Yukio loved to eat as much as Rin did.

But Rin stayed quiet as he watched him go, suspicion gnawing a gaping hole in his stomach. Turned back to the meal that was slowly growing cold on the table, taking a mechanical bite of his rice.

The next time he saw his brother, it was lunchtime. He was sitting on a bench, picking at his lunch absentmindedly, and was it just Rin or did he look a little paler than he had this morning...?

Nothing a little investigation wouldn't solve.

With that thought in mind, Rin trekked over to his brother and plopped down unceremoniously next to him, flashing a toothy grin. "Hey, bro. What's up?"

Yukio—punctual, stonefaced, always-prepared-for-everything Yukio—actually jumped, eyes wide, expression startled. But then he drank in Rin's form and his words, and said, "Oh. Nii-san."

"Nice to see you, too," Rin teased, rolling his eyes. Repeated, "What's up? You sick or somethin'?"

A blink. Two blinks. "Of course not."

"Then why are you acting so out of it?" he accused, the frown from this morning resurfacing on his face. "C'mon, you can't lie to your older bro."

"I'm fine," Yukio said shortly.

Rin's eyes narrowed. Typical Yukio. When would he realize that Rin could see through his lies a long time ago?

Then again, he'd been lied to about his heritage for several years before the truth was so violently revealed to him. And even after the death of their father, Yukio had lied to him. Aimed a gun at his head, finger resting on the trigger.

Inwardly, Rin shook his head. Not the time for that.

"Uh-huh," he said instead, voice dripping with sarcasm. "Right."

A sigh. "Don't you have something better to do than bug me?"

"Like you have something better to do than talk to your own brother? You're just picking at your food like a bird."

"Nii-san," Yukio said in warning, but even when he glanced up to glare at him, it was weak.

Yukio was definitely acting weird.

"Fine, fine," he relented anyway, tying up his bento again to find somewhere else to sit. "I'm leaving. Sorry my company is so unappealing."

Yukio said nothing. Rin didn't see him again after that, but when the time for cram school finally arrived, he found Shura making her way down the hall.

An idea formed in his head and before he could give it up thought he was chasing after her. "Hey! Shura!"

She turned, regarding him with a quizzical expression. "What izzit?"

"You seen Yukio around?"

"Not since yesterday," she answered. "Why? What's the four-eyed chicken up to now?"

Rin fought the urge to frown again. "Not sure. If you see him, keep an eye on him for me, 'k?"

Shura cocked her head to the side. Her eyes narrowed. "Who do I look like, his baby sitter?"

"Listen, I can't explain it," he insisted. "You'll have to trust me. Keep an eye on him!"

She scoffed and rolled her eyes, which made Rin grin because that wasn't a no. He darted off in the other direction, heading toward his classroom, and called out, "Thanks!"

Physical Education came and went the way it usually did—Rin and Suguro competed against one another even though it wasn't a competition, their classmates looked exasperated, and Tsubaki-sensei left early after getting a phone call from his 'kitty.' When class was over, Rin bid Shiemi and the others farewell before making his way home.

He was home for all of three minutes before the front door to the dorm swung open, and an irritable Shura was guiding a pale Yukio inside.

Rin straightened immediately. "What happened? Yukio, are you ok?"

Shura was scowling. "Yer instincts were on point, kid. The chicken's got a fever."

Slowly, Rin's eyes widened, and he took a good look at his brother—he was slightly flushed and sweaty, seeming like he really needed to sit down. Definitely a lot worse than when he'd seen him earlier.

"It's not a big deal," Yukio said stubbornly, albeit weakly.

"Right," Shura said gruffly as she shifted Yukio's weight into Rin's care. "That's why Mephisto himself told me to escort ya home."

"I—"

"Shut up, Four Eyes," Rin said. "Just let me help you for once, ok? C'mon, let's get upstairs."

Shura lingered for a little while longer, staring at Yukio in a strange mixture of annoyance and not-quite worry. Rin eventually sent her off with an easy-going smile, but it slipped off his face when she was gone.

"You coulda just told me you didn't feel good," Rin said quietly as he faced Yukio again. "I could tell something was wrong."

"You could, huh?" Yukio whispered, eyes closed. He was now laying down on the bed, breathing raggedly.

"Yeah. I'm not as dumb as I look, you know."

"I didn't say you were dumb."

Rin quieted, studying Yukio with rapidly growing concern. Out of the two of them, it was always Yukio that got sick. He hoped it was something that he could just sleep off. "I'll make you some broth, ok? Don't move. Text me if you need anything."

Yukio didn't respond right away. Then, just as Rin was walking out the door, he heard Yukio say faintly, "Thank you, Nii-san."

Rin finally smiled—a genuine one, not something that just found its way on his face on instinct. "Anytime, little bro."