Sayu loved her brother, but she thought he was weird sometimes.

Not bad weird, exactly. Not creepy weird, definitely. Just weird.

For example, he had lots of friends, but he didn't really seem to like any of them. For another thing, he was smart – and not just smart like other girls said their big brothers were smart, Light was actually smart. Way smarter than her, she knew, and probably even, she thought, smarter than their parents. His grades were always perfect even though she knew for a fact he didn't really listen in school. She'd tried that once, but it hadn't worked for her.

Mostly, though, she thought it was weird how much he pestered their dad about his police work, how he wanted to know everything about the crimes that were going on, and sometimes even leaped to conclusions that she could tell by the look in her father's eyes he hadn't thought of either. Sayu never wanted to think about the kinds of stuff her father was doing, what the people he tracked down and locked up were up to. Light seemed to breathe it, and she didn't understand why.

Light was a weird brother, but he was a good brother too, mostly, helped her with her homework and didn't get mad when she teased him about the girls who flocked around him even when he was twelve years old. (He was always nice to them, but Sayu could tell that he didn't like any of them, not that way.)

But if there was one thing about Light, he liked his privacy. The one time he'd lost his temper was when he'd come home from tennis to find her sitting on his bed, leafing through one of his big books. He'd actually yelled at her, shoved her out of his room, and hadn't talked to her for hours afterward.

She always knocked before entering his room, and he didn't intrude in her room (which she wouldn't have minded, but he didn't seem interested) and they didn't have that problem again.

So Sayu was surprised when she woke up in the middle of the night to find Light sitting on the edge of her bed, his eyes wide and reflecting the moonlight. He seemed – upset.

She blinked at him, blearily. "Liiiight, I was sleeping."

"I'm sorry," he whispered, and his voice usually sounded so sophisticated and grown up that the slight quaver in it was a surprise to her. "I didn't mean to wake you up. I just came in to check on you, make sure you were okay."

Sayu blinked and rubbed her eyes. "Why would I not be okay?"

"I was reading," Light said, and he pulled his knees to his chest. "Reading about – this case where these people broke into a house, just because, and killed a whole family, mom, dad, and their daughter…"

"Why do you read those things?" Sayu complained. "Don't they give you nightmares?"

"I have to know what's going on," Light said insistently, "If I'm going to be a detective like Dad I have to understand what's going on, I can't hide my eyes from the terrible things people do – but you're my little sister." He seemed distressed, shifting awkwardly to look away from her. "I don't know what I'd do if something happened to you. People do all kinds of awful things to little girls, I've been reading-"

Sayu covered her ears. "Don't tell me! Don't tell me, I don't need nightmares too!" She shoved her brother, trying to be playful. "You'd kick anyone's butt if they tried to do something to me. You'd kill them!"

Light's fists balled up fiercely. "I'm not going to let anyone hurt you if I can help it," he said, defiantly, "But Sayu – I just want you to be careful. You know all the rules mom and dad have? They're for a reason. People out there aren't always nice. I know you're trusting and you like people but – there are real bad guys out there, and they don't always look bad."

"I know, I know," Sayu said with exasperation. "Go back to bed, Light, I wanna sleep."

"Please listen," Light said, insistently. "Just – be careful, okay? Don't trust anyone unless you know them, really know them. And if you're ever not sure, run away and come get me or dad or someone."

"Okay, okay," she said, rolling her eyes, but Light reached out and grabbed both her shoulders, turning her toward him.

"Listen, Sayu! This is important. I have to keep you safe!"

"What's going to happen?" She demanded. "Do you really think some guy is going to come up and kidnap me? I don't think so! That'd just be stupid. Dad'd find me right away, or you would. But they wouldn't do it, there wouldn't be any – what'sit. Motive."

"I don't know," Light said miserably. "It could be. Sometimes things just – happen. Bad things. Without an explanation. I just want you to be careful."

"I'll be careful," Sayu promised, and then hit her brother with a pillow. "Now go to sleep and leave me alone. I'm tired."

His eyes were big and earnest, and he didn't budge. "Promise me you won't get into trouble?"

"I promise," she said, and pushed him off the bed. "Now get out of my room, silly brother."

Light got up slowly, and she could see him biting his lip, but he nodded. "As long as you promise," he said. "I just want you to be careful."

"I'll be careful." She brightened. "And anyway, you're the one who's going to be a detective. If something bad does happen, you can always rescue me, right?"

Light smiled, tentatively, though he still looked uncertain. "That's right, Sayu. If something happened to you, I'd be sure to come get you." He paused, and added, "Goodnight. I'm sorry for waking you up."

"That's all right," Sayu said, lying down with a yawn. "I know it's just because you're worried. Sleep tight. Don't let the bedbugs bite."

He smiled again, and slipped out into the hallway, just like a ghost.