You're Gonna Miss This

Disclaimer: I still don't own it, and I am back to being a poor student with bills, so I'm eve less worth suing.

AN: Another I started a long time ago, originally for Over the River, but it was unfinished and didn't fit. So I polished it up as a story of it's own. Undead Again insert.

For every father, daughter, mother, son, lover or friend who has ever wished life away just a little too quickly.

You're gonna miss this

You're gonna want this back

You're gonna wish these days

Hadn't gone by so fast

These are some good times

So take a good look around

You may not know it now

But You're gonna miss this

- Trace Adkins, You're Gonna Miss This

Castle didn't think he'd ever been so happy to spend time thinking about an impending zombie apocalypse. Sure, that theory had always been interesting in a quirky sort of way. But this case was insane. Which, as he thought about it was exactly what he needed. If this was really going to be the last case he ever worked on, he needed it to be like this. Fun, a little zany. He didn't need the terrifyingly intense stuff today. It was hard enough to contemplate the idea of leaving Kate behind, but leaving her behind and in danger was almost unthinkable.

That thought nagged at his conscience more than he wanted to admit. After all, he still knew more about the potential for Kate to be in danger then she did. Part of him wondered if he should tell her. After all, if he wasn't going to be there to have her back, at least she should be aware that it needed to be watched. But, there was a part of him that couldn't bring himself to do it. Couldn't live with the idea of leaving her behind while she hated him.

Somewhere, further back in the writer's mind then it probably should have been, a small voice kept insisting that it was terribly hypocritical of him to blame her for not telling him the truth while he withheld the truth from her. But his own pain pushed that thought away. Everything he was feeling was just going from bad to worse. His daughter didn't want to be his little girl anymore. And Kate didn't want him at all.

True, they had seemed to reach some tentative level of their partnership again after the case with Slaughter, but still. Still, she hadn't had the nerve to come to him with the truth and that hurt more than the lie itself. But if his mother was right, if he really was punishing Kate, then he had to stop. He couldn't bring himself to keep hurting her, no matter how much she had hurt him.

Of course, that was probably also the reason he couldn't seem to bring himself to tell her that this was the end. Oh, he had seen her face when he is hinted at leaving. It'd taken all of his resolve to pull off his impassive expression, because she did look surprised, maybe even hurt. But it was better this way, if he left he could stop hurting her. And himself.

It wasn't Lanie's case this time, but it didn't stop Kate from seeking her friend out. Because it felt like Castle was leaving. He was hinting at the idea of leaving and it frightened her. She needed her best friend, and really that would be Castle. But Lanie, she had been Kate's friend longer than anyone, and she needed someone to talk to.

Unfortunately, it wasn't until she had arrived at the morgue that Kate remembered about Lanie's own shadow. Alexis had been interning with ME for a while now, but it's still always seem to take take her by surprise when she found the girl down here.

"Alexis," the detective said quietly. "I wasn't sure you'd still be here."

The young redhead glanced her way with a slight smile. "Just finishing some things up," she said absently. "And dodging unsolicited laser tag games with my dad," she added. Then the girl looked up as if startled that she had added that comment into the conversation at all. "Detective," She said urgently as she spun around in the chair she was using. "Please don't tell my dad I said that. I mean, we've talked about it and everything but – I didn't mean it like that, and I don't want him to hear it from you because he'll think…"

Kate held up her hand quickly. "Your secret's safe with me Alexis, although why you'd be dodging your dad is a bit of a mystery to me."

As far as she knew, her partner – could she still call him her partner? – and his daughter had an excellent relationship. And they often seemed to like to play together if her exposure to the pair was any indication. She thought back to the night when she had accidentally stumbled upon the two playing a game of laser tag in the loft when she is gone there for the first time.

The girl looked as if she didn't want to say anything more, at least not today. But then, she seemed to decide that since the information was already out there she might as well open up. "It's not that I don't like spending time with my dad, you know? It's just there are so many things going on right now, and I have so much to do and it's important. It's serious stuff, and my dad can't seem to be serious about any of it. I know he's always been a little – immature – but I mean it's time for me to grow up, you know? It's time for both of us to grow up."

Something about Castle is darker than usual, even the new usual, mood over the last couple of days suddenly began to make some sense to her. Was this why he was so determined to leave? Maybe it didn't have as much do with what was going on between them as she had thought. Or maybe it did, and this was just making it all worse. Or maybe – had Alexis asked him to leave? Kate didn't think she could bring herself to ask the girl that.

Instead, she considered her own position, her own life, and said the first thing that came to mind. "You know Alexis, I know where you're coming from. The first thing I wanted to do when I went away to college was to just get away, set up my own life the way I wanted it. I mean it was different, probably, then it is with you. My parents were very structured, both of them being lawyers. I was trying to get away from rules and it sounds like you're trying to establish them and that's fine.

But, don't be in such a hurry. Don't look forward to it quite so much. The real world can be difficult and dark, and sometimes we need a little lightness, a little familiarity just to get through it all. Someday not long from now, you might find that the things that feel like they're going to drive you crazy now are the things you wish you could have back. Family dinner and laser tag might just be the only thing you really want in a few months time, and then it'll be a lot harder to come by."

Alexis stared at her, she thought the girl had gone a little pale. She decided not to give her chance to stumble through what to say next. "Anyway, I was looking for Lanie. But I guess she stepped out?"

The girl nodded. "She had a late meeting. I could leave her a message?"

Kate shook her head. "No, that's okay. I need to get back. I can call her later. Thanks, Alexis."

The case was over in another day, and Castle found himself facing an ending. One that he was hoping to have convinced himself by now that he wasn't dreading. Then his phone indicated an incoming text. Alexis. It was a single line, but he has to read it three times. What? Kate. What?

Dad, tell Detective Beckett I said thanks for the advice last night.

What?

"Hey, Castle? You okay?"

He looked up, trying to find some way to read her expression. It seemed straightforward, but he'd been wrong about that before, hadn't he? "Yeah, yeah I'm fine. Just - I got a text from Alexis."

"Is she okay?"

"Oh yeah she's fine. She just wanted me to tell you thank you for the advice you gave her last night."

Kate looked instantly unsettled. "Castle - I...listen, if I overstepped, I'm sorry. I was looking for Lanie, Alexis was there and she just seemed like she needed someone to talk to. I didn't mean to interfere."

He winced. Beckett had helped out his kid, and she seemed practically terrified he'd be angry at her for it. She didn't know what was going on here, he realized. Or maybe she did, after today, all that subtext about memory. But she hadn't. So maybe he has been doing a little sinning by silence of his own. Because she was being a friend, even through all of it.

"It's fine, Kate. She's happy. Hell, so am I. I don't know what you said to her, but it helped."

"Oh," Kate said, then looked away as if she were suddenly shy.

After a moment she turned back to him. "I guess mostly I just reminded her that sometimes we can be in such a hurry to move on, we forget the value of what we have. And once we leave it behind, we might find that it's harder to get back to than we thought it would be. When we realize how much we miss it."

Oh God. She was looking him right in the eye now, those beautiful hazel eyes of hers on his. His throat closed up.

Somehow, they segued into the case after a long moment of awkwardly loaded silence. And he didn't expect it, but then Kate was telling him about her year of therapy helping her to face her shooting. And he knew that she knew, could see it in her eyes as she told him she wanted him to be there when she finally came through it.

Suddenly, he knew he wanted that too. He didn't want Kate Beckett to be the thing in his life that he missed.