This goes directly with the crossover Assimilation I've written, but it can be read on it's own. The age is completely and utterly fucked up to those who haven't read Assimilation. Tomoe and Kenshin, none romantic. Enjoy. As stated, may seem strange to anyone who hasn't read the crossover. Modern, so slightly AU I suppose.

I don't own RK.

Frailty

Tomoe woke up to hear a soft murmur of pain. Like her both her mother and her father, she'd always been a light sleeper, so it was easy to wake her up in the middle of the night. She sat up, vaguely confused, because there was only one person who could move around without pulling her out of dreamland and the sound must have come from him. Odd. Stifling a yawn, she pulled herself out of bed and left the room.

"What's wrong?" she asked as she entered her "son's" room, where he sat upright against the wall, sword against his shoulder like usual. His head was buried into his knees and she could see that the small hand clutching the sword was almost white.

He lifted his head, but winced immediately afterwards. In answer, he shook his head, giving her a silent Nothing, causing him to flinch in pain again. With a small sigh, she walked over and sat down across from him.

"Does your head hurt?" she said. His breathing sounded a little labored, but quiet. Everything about him was quiet. She reached her hand over and placed her hand to his forehead. "Well, you don't have a fever…" He shrugged. He was trying not to shake.

Wondering if he'd kill her for doing this, she scooted herself over so that she was next to him and wrapped one arm around his shoulders. For a moment, he tensed, then relaxed. She gave a soft smile; maybe they'd gotten so used to playing the part of mother and child that it was no longer a part to play. A sad truth, she supposed.

"Sorry for—" He broke himself off and she felt a quiver go up his entire body. He made another soft sound of pain. Then he relaxed again. "Waking you," he finished.

"Don't worry," she answered, stopping herself from saying 'darling' as she often did in town. "It's fine." There was a long silence, broken only occasionally by the crickets on the windowsill outside, their breathing, and his random, stifled cries of pain. Whatever was happening was bad. "Where does it hurt?"

"My temples," he answered quietly. "The top of my head…above my nose."

Tomoe looked down at the top of the small boy's head, to his messy red hair, and it occurred to her that this was just a small boy eleven. This short, skinny, eleven-year-old boy was the Battousai, the most feared killer in all of Japan—hell, the entire world. He'd killed her fiancé and she'd come to take her revenge. But then…seeing him at times like this, she found herself wondering if she could do that. Could she really kill a frail little boy, even if he'd killed so many others? And now to think that she had her arm around him, holding him as he tried not to cry. It would be the perfect moment to end him, but she couldn't do it. It may have only been a month, but he was her son. It was no longer make-believe.

And she loved him.

Inwardly, she sighed. "That sounds a bit like a sinuous infection," she said. "Does it hurt anywhere else?"

"No…"

"Or a migraine. Can you see clearly?"

"Not really…" That fact that he was resorting to talk worried her; normally he'd just nod or shake his head. "Damn it."

"Don't swear," she said on instinct, used to reprimanding her little brother who was only a year or so older than Kenshin, now that she thought about it. She heard a weak laugh. "Do you feel nauseous? Be honest."

"A little…"

She pulled him closer. He moved into her touch. It was a bit of a surprise. She reached over and pulled the katana from his hand. There was no complaint—all he did was grip his knees instead. "I'll get some Advil in a moment. How often do you get these?"

"Every once in a while." Which for him meant often. She wondered how many she missed. "It-it's never been this bad on a normal day before."

Normal day…? Well, he was venerable and she'd use it against him to get answers, just like any mother would. Any mother. What a funny thought. By now it was hard to believe that he wasn't her child—though she supposed that was a good thing, since she would have been sixteen when she had him. When they came here they'd lied, saying that he was ten and she was thirty-two, making it more believable. It worked too, so Tomoe sometimes wondered if she should be insulted that someone thought her nearly five years old than she actually was.

"What's an abnormal day?" she asked. They were both talking more than they usually did. "When do you normally get them?"

That same quiver went through his body again and he made a small scream that he'd been trying to force down. Her heart broke, just a little. No. When the time arose, she'd tell them that she could no longer do it and that they'd need to get through her to get to him. Hard to believe it…he'd taken away the love of her life and given her a new one, a new way to love someone. She'd been sent to befriend and betray him, but now she was planning on protecting him as his parent, a parent she doubted he ever had.

"After I kill someone." A shiver went up her spine. "My-my eyes change color apparently. When they go back, the headache starts. But I didn't kill anyone today, so-so—" He made that little strangled scream again.

"Shh…it's okay. I'll go get the Advi—"

"No!" he said, surprising her. He went to go move his head up to look at her, but didn't even move it a fraction of an inch before he made that sound again. It broke her heart to see him like this and she hadn't known there was anything left to break. "Stay here, please…"

"I'm here, Kenshin," she whispered, placing her head onto of his and holding him more tightly. "I won't leave. When the pain goes down, then I'll go get it."

"O-okay." The two fell silent.

Maybe she'd changed her views on the human heart. When her Kiyosato died, she thought the heart could only shatter once and never be mended. But she supposed that's what helplessness did to a person. But now she knew better—the human heart was more like glass. When it broke, all it did was turn back to the finest bits of sand it was created from. And then when it healed, the sand built itself back up to form anew. All it needed was a glass-blower. Apparently Kenshin was hers. His breathing continued to come out as if he needed to force it.

"Can you move?"

"I'm not sure…"

"Here, I'll help you."

After a moment or so of waiting for an answer and receiving none, she removed her arm from his shoulders and stood. She reached out her hand to help him and he grabbed it, with a grip less secure than usual. Then she pulled him up. He winced immediately from the pain and stumbled forward. Her arm went out and she caught him, the same way he caught her on the first night they meant in the rain he made bleed. The same umbrella she'd stood under was leaning on the wall next to their front door. The body in arms was so light it was like she holding nothing.

"Come with me, we'll go to the kitchen," she said as he composed himself. Now he was shaking nonstop. Another grain of sand fell. She sat him in a chair and went to put on the lights, but lowered her hand. That would only make it worse. "Is your vision still blurry?"

"Y-yeah," he answered.

Glancing back, she noticed that his eyes really were slightly unfocused and she had a feeling this wouldn't be the last time she'd see that look, that hopeless, hopeless gaze. She filled a glass of water and removed two pills from the bottle. If the headache weren't as bad as it was, then she would've only given him one. He didn't look like he weighed enough for much more.

"Take these, you'll feel better." With a quivering hand, he took the pills and the water (she kept the glass partially in her own hand, too). He swallowed them and made a face of distaste. "What, haven't you ever taken pills before?"

"Once," he answered. "When I was nine and had the flu."

Tomoe sighed. "Well, if you feel a headache starting, the Advil is here on the counter. At most take two, but only one should be enough most of the time. You'll feel better in about fifteen minutes. Let's just…stay here for now."

She pulled up a chair next to him and once again hugged him, this time with both arms. He deserved it.

"Thanks," he said in a small voice, putting his head on her shoulder. His skin was pale and his body still shaking. It really did look like he had a fever. She was slightly surprised he didn't.

"And you're welcome," she answered and just because she needed to hear herself say it, she found herself adding, "Darling." Again, he laughed weakly. There was a short silence. "Where's your family?" She wasn't quite sure where the question came from, but it came anyway.

"You're my family, Tomoe," he answered and she smiled. Another smile silence. "I don't have a real family. I haven't since I was five. Did you?"

Her heart beat rapidly. "I had a brother, Enishi," she said. "And a father and I was soon to be wed, but the man died." By your hands, my love. I'm so sorry. "Do you feel any better?"

"I'm starting to…I can move now."

"Come on, then." She let go of him and grabbed his hand again. He didn't stumble this time. Together they walked back to his room. When she was his age, her mother was still kissing her goodnight. Now at that same age, he was suffering from headaches every time he killed. It was a sick world they lived in. "You should probably lie down rather than sit when you sleep."

"I can't." The answer came immediately. "I can't sleep lying down."

For what seemed the hundredth time that night, she sighed. Sometimes she wondered what others would think of if they saw this—saw her helping the deadly Battousai with a headache and talking to him about sleeping and family. The others in the resistance movement would be shocked to see Kenshin acting like someone his own age, smiling and occasionally laughing, something he only did for her. Never for someone else. Her family would just be confused to see that she'd "adopted" a child and she wondered if her brother might feel a little betrayed to see she could love someone else. Anyone else in town might find it a little odd that he called her by her given name.

"Go to sleep," she said. "It'll be better in the morning."

"Okay." Suddenly, an overwhelming feeling came over and she wrapped her arms around him. Kenshin didn't stiffen like she expected him to do, but he didn't hug back either. This little boy…this poor, sick, little boy whose hands were stained with the blood of thousands….she couldn't kill him. It almost hurt her, knowing that at one time she'd been prepared to. She never expected to love him like this. It was just so strange.

When she kissed the top of his head, he jumped. "Goodnight," she said, releasing him. "I'll see you in the morning, darling."

Vowing to protect him from himself and from others, she left the room, the word darling still lingering in her mouth.