Author's note:

I'm really not sure where this came from. It's not my usual take, not my usual subject matter, and not even my usual fandom. But it occurred to me, and I had to write it. It takes a number of things (starting with a shift in the relationship) for granted, but I think it should be clear enough without explanation.

This is my first attempt with these characters, and feedback would be much appreciated.

In any case, hope you enjoy…

Saturday

He just wanted her to be happy.

In general, of course.

But he wanted her to be happy about this.

He wanted to see the pure and unadulterated delight, the kind that he felt, reflected in her eyes.

He wanted everything.

The warmest moments life had to offer.

He wanted her to understand what it all could mean.

But instead she looked miserable.

And it broke his heart.

She was rushing around the bedroom they'd been all but sharing for the better part of the last six months, pulling clothes out of the closet that she'd refused to move any of her things into until just eight weeks ago.

She was avoiding his eyes, staring at nothing.

Painfully on edge.

Horribly distressed.

And he could have cried, to watch her.

He said nothing as she grabbed her jacket and left the room.

It was crazy.

And, also? It sucked.

Half an hour ago he'd been half-awake and watching her doze, concerned only with what to make her for breakfast, and whether it would be before or after some decidedly likely morning sex.

But then her eyes had popped open, and she'd jumped from the bed, dashed for the master bath.

And it wasn't that he hadn't been concerned that she was sick.

It was just that the thought of it had occurred to him then.

And he liked it.

In the five minutes it took for her to finish emptying her stomach and wash up at the sink, he had time for dozens of memories and dreams.

And he liked it.

Loved it.

Wanted it.

And he'd said to her, eagerly, as soon as she emerged from the bathroom –

"You know how they say birth control is never a hundred percent effective?"

He'd smiled.

And she'd stopped cold, processed the thought.

Apparently, realized it was possible.

And then there was that look.

The one that bordered on misery.

And now here he was, alone.

…

He wallowed in his apartment for the better part of two hours.

Then he couldn't take it any more, so he followed a hunch and found her at the station.

He'd expected her to be catching up on paperwork (and practicing a little avoidance), but he found that Ryan and Esposito had apparently been called in, and they were already putting up a murder board.

He entered cautiously, coffees in hand purely out of habit.

He tried to hand one of them to her, and they each froze with one hand on the same paper cup.

Realizing, he presumed, at the same moment, that he was handing her a hefty dose of caffeine, and she just might be pregnant with his child.

He met her eyes, started to apologize, but she cut him off –

"Thanks, Castle."

- and put the coffee down on her desk.

"What did I miss?" He queried, well aware of the curious looks they were receiving.

"I got paged on my way in," she told him.

"And you didn't call me?"

She, too, had to be aware of Ryan and Esposito's eyes on them.

So he wasn't surprised when she just forced a casual shrug.

"I was about to." She cleared her throat, then filled him in, her eyes on the board: "Jillian McMurty, twenty-four. Dog-walker found her in the park. Strangled."

She broke off, said nothing for a moment, then turned to the guys:

"Ryan, let's get a look at those phone records. Esposito…" It took her a moment of thought. "See what you can get from what she's been spending her money on."

The guys didn't move.

Esposito cleared his throat, looking at them both.

But he apparently thought better of asking any personal questions. Instead, he asked:

"Where are you going to be?"

"Like, in case we need you," Ryan tried to add smoothly.

"I'm waiting on Lanie -" Beckett started.

And her phone beeped, as if on cue.

Relief crossed her face -

"Speak of the devil."

- and she started to move for the door.

Castle tried to fall into step with her, but she waved him away.

"I got this," she said quickly.

And he found himself standing alone, again, as she walked away.

Alone, until he felt Ryan and Esposito at his back.

"Dude," Esposito half-whispered into his ear. "What part of 'if you hurt her, we will obliterate you' didn't you get?"

"Was it just a fight?" Ryan wanted to know. He sounded hopeful.

And as Castle walked away from them, he heard Ryan whining like a disappointed child:

"Man! See, I knew this was going to happen…"

…

Castle made his second careful approach of the day down in the morgue.

He could hear them talking – Beckett and Lanie – as he crept close enough to peer around the door.

Beckett was seated, her sleeve rolled up, a cotton ball pressed to her inner arm.

She talked away while Lanie worked at a lab desk.

And truth be told, it hurt.

It wasn't fun to realize that Beckett was having Lanie run a test, and this was how they would find out.

Beckett, miserable and confiding in someone other than him.

And him, alone and eavesdropping in the hallway.

It wasn't right.

Still, he didn't move.

Listening.

"The fact that I could be two weeks late and not even realize it just speaks to just how married I am to my job," Beckett told Lanie.

Lanie came back with:

"It also speaks to just how stressed you've been. Could be that."

"Stress doesn't generally induce a cookie-tossing incident," Beckett pointed out.

Castle could almost hear Lanie shrug, as she replied:

"Not unheard of."

And there was a moment of silence, before Beckett admitted:

"I haven't really been all that stressed. Busy, yeah. But every night…"

She trailed off, and Castle felt his heart squeeze.

Every night, indeed.

Those nights were burned into his memory.

It had been six good months.

"Would it be so bad?" Lanie questioned.

And Castle held his breath.

Waited.

Finally, he heard Beckett reply:

"I don't know."

And it wasn't particularly comforting.

But she sounded lost.

And damn if he didn't just want to walk right in and wrap her up in his arms and make her see the light.

And he might have, if she hadn't kept talking right then:

"All I know is that last night I went to bed thinking about whether I could get all my Christmas shopping done in one day, and today all I can think is that I might be about to tie myself forever to the most immature man I've ever met."

That was a blow.

It hit hard.

And he backed off.

Stopped listening.

Made his way over to the bottom of the stairs.

And wallowed some more, his head in his hands.

…

When he heard footsteps ten minutes later, he looked up and found her stopping short at the sight of him.

She was in tears, and part of him wanted to hold her.

The other part of him wanted to pick a fight.

He did neither, instead waiting for her to make the first move.

She opened her mouth to say something, then stopped.

Maybe wondering what he'd heard.

She tried again, stopped again.

So he let her off the hook:

"It was positive?"

She took a deep breath.

Looked away from him.

"Yeah."

He nodded, and wanted to cry himself.

This moment wasn't what it should be.

"We have… I have a case," she told him.

And then she stepped around him, and she was gone.

…

He had nearly caught up to her by the time she reached her desk.

He knew she wanted to escape into work.

He wasn't sure he'd be able to wait until that night to have a real conversation.

But it turned out he wouldn't have to:

"Where've you been?" Ryan asked, more curiously than accusingly. Then he grinned like a kid: "Guess who got a confession!"

Confusion registered on Beckett's face:

"Did I miss the part where we found a suspect?"

"We had a walk-in," Esposito filled in, less than impressed with Ryan's exuberance.

"But he confessed to me," Ryan pointed out.

"Please, Man, that guy was ready to pour his heart out to anybody who'd listen."

"Dude, why you gotta do that?" Ryan complained.

But Esposito bottom-lined it for her:

"Point is, Captain's getting him booked, and you got your Saturday back." He smiled a little smile, maybe trying to cheer her up.

Beckett nodded blankly.

Less than thrilled with that.

And when the others had gone, Castle stepped up to her.

"Can we -"

But she cut him off, though her tone was gentle:

"Can I just have a little time?"

It might have been a reasonable request.

But before he had the chance to decide, she turned and walked away.

…

He was halfway home when it all boiled over in his mind, and he knew he couldn't wait.

He found himself knocking on her door.

There was no immediate response, so he knocked again.

And when she swung open the door, he didn't wait to be asked in.

"I heard what you said to Lanie," he told her. "And it wasn't fair."

"Castle -"

"It. was. not. fair."

She stepped back into the apartment, waited for him to follow suit, and shut the door behind him.

Then she leaned against the back of her couch, sighed a heavy sigh, and told him:

"I'm sorry. I am. I didn't know you were there. But it shouldn't surprise you that this is a big deal for me."

"A big deal I get. A big problem on the other hand -"

"Castle, answer me something. Why are we together?"

That was easy:

"Because I want to be with you. And I thought you wanted to be with me."

That gave her pause for just a moment, then:

"As far as I can see? We're together because it feels good. And because somewhere along the line? I didn't want to resist. But we never talked about it. We never planned for a future."

"We talked."

"When?"

"All those nights!"

"Oh, all those nights? In the heat of the moment? Those nights? That wasn't talking, Castle, that was pillow talk."

He was hurt again, couldn't seem to stop that pattern. Found himself insisting:

"That meant something."

"Are you going to stand there and tell me that all those things you said to me are any different from the things you said to every other woman you've -"

"Yes!" Then, he had to admit: "Not everything, but when I say 'I love you' -"

"You don't say 'I love you', you say 'God I love you', you say 'God that was good'. But day to day, outside the bedroom -"

"I say -"

"Unless it's said like a joke -"

"Hey…" He took a breath. Did she really not get it? "It's not a joke. It's never been a joke. Sometimes I try to keep things lighthearted…" And then anger reared its ugly head: "That's really not the point!"

"Then tell me, Castle, what's the point?"

"The point is that I thought you knew! If nothing else, I thought you knew that this is the one specific area in which I most definitely excel! Maybe I'm not so sure of everything as I like to pretend to be, but the one thing I'm completely and totally one-hundred-percent certain of is that I am a good father!"

She softened at that, rubbed her eyes.

"I never -"

"No, no, no, wait a minute – I not only did the 'Dad' thing, I did the 'Single Dad' thing, okay? I stayed up night after night after sleepless life-sucking night, I walked the floors, I cleaned up the vomit and I washed the crayon off the walls and I went to every doctor's appointment, every parent-teacher conference, and when she hated the dentist? I turned it into a game! And to this day, she is the only kid you'll ever meet who gets excited about dental work, which she rarely needs, because I am a good father!"

He took a breath.

Realized that it was quite the tirade.

And spoke more softly when he added:

"So don't tell me I'm too immature for this."

Tears came to her eyes again at that.

"I'm sorry," she murmured. "I'm sorry." She was quiet for a minute, then she added: "But I thought you knew me better than this, too."

"What does that mean?"

"This isn't me." She rubbed her forehead, looked around her apartment. "I don't fall into the big things. I never have. I make plans, and I make choices. And I always thought that if this happened for me some day, I'd be secure in the relationship I was in. And it would happen by choice. So I'm sorry that this is me freaking out! But this is big."

He almost chuckled, but thought better of it.

"Well yeah!" he said instead. "Hell yes! Honey - this is big! This is bigger than big. But there's a bottom line here."

"What's that?"

"Do you want to have kids?"

She didn't have to think for too long:

"Yes."

"Okay, follow-up question:" he prompted. "Do you want to have a child with me?"

That one took longer, and in the time it took her to answer, his heart climbed slowly into his throat and he realized that her answer had the power to break him.

Mercifully, she finally murmured:

"I might."

And he released his breath, and held back tears.

And she dared to meet his eyes, and said it again:

"Sometimes I think I might."

He moved to embrace her.

She held him off, told him:

"I'm not saying that this is -"

"Okay, before you say what you're saying, let me say what I'm saying, okay?" He looked her directly in the eye, told her: "I'm saying that as far as I'm concerned? This is a secure relationship." He dared to take her face in his hands: "Right here, right now, in what is most definitely not the heat of the moment, I am telling you that I love you, as much as I've ever loved any woman, and probably more." He stopped, wiped a fallen tear with his thumb. "I've been married, I've said 'forever', and I can tell you… you and I are not what I was with either of them. Mainly because marrying them was easy. Mainly because…"

He paused, locked eyes with her again.

Told her:

"I love you so much more than I am comfortable with."

She broke down then, wrapped her arms around his neck, and held on tight.

"Is this good crying or bad crying?" he whispered into her hair.

And she leaned back and looked him in the eye.

Told him:

"Castle… that is exactly…" She sniffled, dared to smile. "That is exactly how I love you."

And then he was holding her.

And maybe things were going to be okay.

…

They curled up on the couch together, both of them emotionally drained.

Her eyes were closed, and she looked more peaceful than she had all day.

He thought maybe she was adjusting to the idea.

He thought maybe she was feeling more secure.

And he still wanted to see that look on her face.

Still wanted her to be happy about this.

Maybe it was selfish, since she looked ready to pass out, but he wanted to convince her to go see a doctor, right then.

Because maybe, if it wasn't too early, and if she could see the image of their child on a screen…

Maybe it would all be clear to her.

Maybe all her 'what-ifs' wouldn't matter.

Maybe she'd melt.

"I know this doctor," he started, "The guy's a friend of mine, a fan-slash-friend -"

"Of course he is."

She didn't even open her eyes, and he enjoyed the return of her sarcasm.

But he wasn't letting this one go:

"He'd totally take us at a second's notice -"

"Of course he would."

"Kate," he prompted, and he waited for her to open her eyes.

When she did, he told her:

"We've been doing this wrong all day."

"And we're going to fix that by going to a doctor?"

"We could see it! I mean, it'll look like a grain of rice, but it'll be there."

She looked decidedly suspicious at that.

"It?"

"The baby," he told her.

Suddenly, the unease crept back into her face.

And he realized that it might have been a mis-step.

"Can they even do that this early?" she questioned.

"Well, grain of rice, like I said, but…"

He stopped, looked at her.

Remembered, for a moment, what it had been like for him the first time.

Realized, taking her in, that it was too much, too soon.

Still too new.

And he wasn't going to rock the boat.

"You know what, never mind," he told her.

And he placed a quick kiss on her head, then her shoulder.

And he said, as much to himself as to her:

"It can wait."

…

They both dozed off, and were woken by the ring of his phone.

It had started to get dark, and he tripped on her coffee table as he rose, and cursed aloud as he scrambled for his phone.

"You or me?" Beckett murmured sleepily.

"It'll be mine," Castle said quickly. "We forgot all about -"

"Alexis!" Beckett realized, sitting up.

Castle managed to find his phone by the door, even in the dark.

He spoke into the phone, foregoing a 'hello' -

"Honey, I'm sorry, we're on our way."

…

"Thank you for coming," Castle was telling Beckett, as they arrived outside his door. "She's been downloading eggnog recipes and de-tangling Christmas lights for days."

"A promise is a promise," Beckett returned. "And who do you think helped her with all that de-tangling?"

He smiled, remembering.

"All the same, I know under the circumstances -"

"I'm not opposed to family warmth, Castle."

He smiled again, moved to open the door.

She caught his arm.

"That said," she started. "I'd like to keep our… news… to ourselves, for now."

He gave her complete honesty:

"That's going to be hard for me, with them."

"I know," she acknowledged.

"I won't say anything without speaking to you first."

"Deal."

They exchanged a nod, and he opened the door.

And inside –

'Family warmth' was an understatement.

The main lights were out, the room instead lit by what had to be hundreds of sparkling colors.

They were there to decorate the tree, but Alexis had gotten started on the rest of the space without them.

There were reds and greens everywhere, holly-and-ivy lining the stairs.

Gentle holiday instrumentals drifted from the built-in wall speakers.

And in the middle of it all, Alexis was beaming.

"Most wonderful time of the year, right?" She smiled at her dad.

"So right," he returned, moving to hug her.

Martha emerged from the other room and greeted Beckett with a warm smile.

"You haven't seen anything done right until Alexis Castle has put her mark on it," she noted, giving Beckett a quick squeeze. Then she added: "We're past five, Honey, let's break out the 'nog."

Beckett nodded absently, and stood back and watched as Castle and Alexis giggled over a box of old tree ornaments.

She'd been spending a lot of days and nights here, in this warm place, with these wonderful people.

But it felt different now.

It felt like the start of a life.

And she willed herself not to choke up, as Castle made his way over and handed her an ornament to put on the tree.

…

Castle was in his element, as he lifted Alexis to put the star on the top branch.

"This is silly," his mother noted.

"I know," he told her.

"She's far too big, even with that perfect little body of hers, to be lifted to the top of the tree."

"I know," he told her.

And he did, but neither he nor Alexis cared.

It was tradition.

And tradition, it mattered.

It was theirs.

It always had been.

And there was giggling and hugging as he put her down, and she ran for the electrical outlet in the corner of the room.

His mother was at the counter – at the eggnog – when the new blast of lights came on.

Alexis stayed kneeling in the corner by the plug, taking in the whole room.

And so it was just the two of them – himself and Beckett - standing there taking the brunt of the blazing colors.

And he looked over at her, caught the look on her face –

And caught his breath.

Because…

There it was.

That pure look he'd been waiting for.

The joy, the hope, the awe –

The happy tears.

He wrapped his arms around her from behind, stared into the tree with his face next to hers.

"This is what it's like," he whispered.

He felt an emotional breath shudder through her.

And he said it again.

Feeling the full weight of it, himself.

"This is what it is."

…