Summary: In which an accidental confession reveals much more than Castle intended. Spoilers for 5x10.

Author's Note: Because Castle + Beckett + Meredith is just too much fun. Thanks to teelduo for the cover art!

Disclaimer: Pretty sure the Castle writers haven't been stuck without power for 3 days due to the hurricane. Yeah, didn't think so.

Overheard

Chapter 1

The door swings open the moment his key turns in the lock, flinging Castle and Kate inside. He's wrapped around her from behind, chest pressed solidly against her back, and the moment they clear the doorway he's spinning her in his arms, pressing her back against the door. It falls shut with a thud as her shoulder blades collide with the metal, and she tugs Castle even closer, one hand twisting into his hair as she guides his lips back to hers.

Tongues tangle and teeth clash as their fingers claw at each other's jackets, fumbling for buttons despite the chill still stiffening their digits.

They left the precinct half an hour ago, and at the mention of a cozy evening in front of the fire with hot chocolate and butterscotch schnapps, things turned...heated...on the drive home. Alexis is away for the rest of Christmas Break, off to Europe with Meredith. His daughter kissed him goodbye this morning as she lugged a giant suitcase down the stairs, promising to let him know when she arrived at the airport that afternoon. By his watch, Meredith should have picked her up an hour ago and they should be arriving at JFK anytime now. His mother is out, and that means that he and Kate have the loft to themselves for the night.

Both of them are so wrapped up in each other that neither hears the clicking of heels across the floor of the living room, the gasp of surprise. Kate is just sliding Castle's jacket off his shoulders when someone clears their throat, and the two hastily jump apart.

Kate's eyes widen and Castle turns around sharply, potential embarrassment fading to annoyance as he takes in the red-haired woman standing in his foyer, hands on her hips, a smirk on her face.

"M...Meredith," he stammers, running a hand through his hair to tame it as much as possible, a lost cause after having Kate's fingers hungrily raking through it just moments ago. "Wha...what are you doing here? You're supposed to be...on a plane."

"Well, darling, it's looking as though Alexis and I aren't going to be able to make it," she answers, sweet as could be.

"And why's that?"

"She's coming down with something, or so she says." The woman gestures over her shoulders. "She's up in her room right now taking a nap."

"I..." Castle glances back at Kate who is standing behind him, fingers wrapped firmly around his wrist. "Umm...I...we..."

Meredith raises a perfectly plucked eyebrow, steps closer. "I have a pretty good idea what the two of you were about to do. Although I have to admit that I'm surprised to see," she gestures over Castle's shoulder, "that you're with...her."

"Meredith," Castle all but growls, and Kate tightens her grip on him, holds him in place.

She flaps a hand in their direction, speaks unaffectedly. "Don't worry, I'll leave you to it. I'll just...go set up my things in the guest room, I guess."

Meredith turns away then, leaving Castle and Kate frozen in place as her words sink in. She's going to 'set up in the guest room?'

No.

Just...no.

The red head lifts two bags from the floor beside the sofa, crosses to the stairs without saying a word, though Kate can see the intentional toss of her hair, the blatantly exaggerated sway of her hips as she walks. As if she's attempting to lure Castle into following her and actually thinks her efforts will be successful.

"Do something," Kate hisses from behind him, the annoyance in her voice excessively clear, and her menacing tone snaps him from his stupor.

"Meredith," Castle manages, clears his throat before continuing to speak. "Hang on a second."

She whirls around casually. "Yes."

"We need to talk."

She sets her bags down slowly. "Okay..."

Castle turns to Kate, lowers his voice. "Give us a sec, kay?"

She nods, possessively leans in to steal a kiss from his lips before disentangling their fingers and making her way to his bedroom, attempting to appear neutral and unaffected by Meredith's surprise appearance.

Castle discards his jacket onto the back of the sofa, steps into the center of the living room. Meredith approaches as well, stopping a few feet from him by the coffee table.

"So what's the problem, Richard?" she asks innocently, voice dripping with sex, and Kate curls her hands into fists as she hears the woman's lilting voice float across the loft. If there's one of Castle's exes she likes the least (not that she's particularly fond of any of them), it's Meredith. And now the woman is here and interfering with their evening plans. For the most part, she trusts Castle to deal with this accordingly, but she doesn't necessarily trust the other woman to heed his words.

"Meredith, you don't live here anymore," he begins.

"No, but Alexis does," she answers right away, as though she already has this all planned out. Of course, she probably does, because it's evidently clear that she's intending to stay here with Castle. In his bed.

"That doesn't give you an open invitation to just," he gestures around, "make yourself at home."

"Come on, Richard, I've always stayed here when I was in the city."

"Yes, well, things are different now."

She steps closer. "They don't have to be. We could still have plenty of fun."

"Meredith," Castle stammers, taking a step back. "I'm in a relationship."

"Oh, come on," she purrs, stepping closer again and reaching out to rest her hand on his chest. "We never had another chance for a new top ten."

"And we're not going to," he manages, eyes flicking briefly to her lips and back, and he can see that she notices because she steps even closer, leans in so her mouth is at his ear.

"But you want us to."

Castle swallows hard, forces his mind to focus. Yes, Meredith is the mother of his child, and yes, he loved her at one time, and yes, she's always held a certain allure, a certain power over him. Before Kate, he would've had no trouble falling back into bed with her. But now...now there's no way in hell he's going to allow his past to destroy what he's built in the present.

He steps back forcefully, clears his throat. "Meredith, stop. We're not...we're not doing this. And if you can't understand that then please go find another place to stay."

"She's really got you on a tight leash, doesn't she?" the woman asks tactlessly and Castle has to dig his fingernails into his palms to stop himself from physically shoving her out the front door. "You used to be so much more fun."

"I love her, Meredith," Castle states, conviction returning in his voice now in full force. "I waited four years to be with her because I knew she was worth it. And now we're together and I love her and there's no way in hell that I'm letting you get in the way of that."

Meredith tosses a look over her shoulder in the direction in which Kate headed upon arrival at the loft, turns back to Castle, perfect eyebrow raised. "How's she so much better than me?"

"Well for starters," Castle snaps, his restraint disappearing at her words, "she doesn't sleep with other men."

Meredith pales but holds her ground, voice still dripping with saccharine sweetness. "You know that didn't mean I loved you any less."

"I don't care," he replies bluntly, beyond caring about maintaining civility. "It happened. And things between you and me...they're over. For good."

"So someday in the future, we can't...?"

"There is no someday."

His words finally seem to have an impact because she steps away, eyes losing some of their sultry quality. "You're serious about her." It's not a question.

Castle's voice is resolute, confident. "I am."

Meredith nods slowly as the full reality of his words sink in, glances again in the direction of the master bedroom. "She lives here now?"

"Not yet," he replies, anger leaving his voice now that he and Meredith appear to be at least somewhat on the same page. "But she will."

She raises an eyebrow again, cattiness returning. "You seem pretty sure of yourself. Then again, there was a time when you were sure about us, too, wasn't there?"

Castle steps closer, speaks in a low voice. "I'm going to marry her, Meredith. I'm going to spend the rest of my life with her. So yes, I'm absolutely sure of myself. Now," he gestures to the door, "you can show yourself out."

Meredith holds his gaze for a minute longer, finally turns to retrieve her belongings, entire body deflating as she gathers her bags. Her poise and grace that was so present at the beginning of the conversation has evaporated, leaving her stunned and upset, though in her defense, she does a fairly decent job of disguising it.

Castle stands there and watches her go, frozen in place even as she opens the door, tosses a smile and blows a kiss over her shoulder. He barely even reacts, his last words playing on a loop in his mind as he realizes what he's just admitted out loud. Sure, it's been in the back of his mind for a while, but now...

Behind the bookshelves in his office, Kate too stands frozen, rooted to the spot, eyes wide with shock, heart pounding. He wants to what? They haven't even been dating for a year. And he already...what?

Through the gaps in the shelving, she watches him regain his composure, approach the office, and still she finds herself unable to so much as take a single step in any direction. And before she has an opportunity to contemplate her next course of action, react in any way, Castle is stepping through the doorway, eyes flitting around the room.

When they land on her, he stops dead, panic evident in his gaze.

"Kate..."

Thoughts?