A/N: This was written for an anonymous tumblr prompt - Caskett season 4 AU. Ryan's wedding happens sometime after 47 Seconds.

He's been having several versions of the same argument all day – the past few days, really – and as Castle drapes the tie around his neck, tugging it into place around his raised collar, he stares into his bathroom mirror and fights with himself one last time.

Some despondent part of him wants to throw the tie to the floor, kick it across the tile, and leave it abandoned in the corner with his stupid, too-open heart while he hides in his office with a drink. Getting dressed up and forcing the corners of his mouth upward for the next several hours will only worsen the headache that's settled into a rhythmic reminder of how much he doesn't want to think anymore. Alcohol would help with that, too, and the decanter in his office beckons further. That invitation is far more enticing than the one for which he's already rsvp'd, though he supposes there will be plenty of options for drowning his sorrows at the reception; if he can just make it through the ceremony, he'll be okay.

The angrier side of him rallies then, shouting that there is no reason for him to settle for "okay" when he has every right to enjoy himself in the company of people he considers friends. He will hold his head high as he celebrates Ryan's wedded bliss, grinning as he offers a toast to happiness, even as it seems to have slipped through his fingers. And she'll be there, of course, her brilliantly wide eyes and lying smile certain to make promises she never intends to keep, but tonight will be an excellent time to stop caring. In fact, maybe it's the perfect test to see if it's worth being part of their immediate family any longer. Perhaps he can simply share one final night of laughter with them before he bids them farewell.

And fuck, that hurts. He wants to tell her he loves her a million more times before he ever has to say goodbye.

Scowling at his reflection, he realizes he's made a mess of his Windsor knot, something he should be able to create in his sleep, but apparently can't manage while he's distracted by thoughts of Kate and all the hopes she'd crushed so absolutely with thirteen not-so-lucky words.

I was shot in the chest and I remember every second of it.

He fixes his tie and squares his shoulders, welcoming the illusion of confidence he doesn't actually feel. It's probably good that Alexis bailed as his date; though he isn't particularly thrilled about the loneliness inherent in attending a wedding without a plus one, his daughter shouldn't be a witness to his special brand of melancholic resentment. Had there been any more notice, he probably would have found a buxom blonde to bring along, someone fun and uncomplicated to keep him company from the church to the dance floor and everything in between.

Instead, he's on his own.

It's a reality he needs to embrace, and tonight seems like a good time to start.

Smoothing the front her dress with her free hand, her clutch in the other, Kate scans the gathering guests for Castle and Alexis even as she admonishes herself for being so damn obvious. It's ridiculous to be anxious about his arrival, but ever since the end of the Boylan Plaza bombing case and his decision to go home instead of having a drink with her, there has been an uncomfortable distance between them. And she doesn't think it's solely because he'd turned her down – he's not under any obligation to take her up on a purely social offer – but there had been something unapologetic about the way he'd walked away from her, and she's felt it in every reaction he's had to her presence in the few days since.

Something is not quite right in Castle's world; still, he's a light-hearted romantic and a wedding is the perfect setting to help him smile again. His daughter may be his date for the evening, but Kate will gladly stay close enough to get that celebratory drink with him at the reception. Better late than never.

She finally spots him, just as tall, dark, and handsome as she expected him to be, and she takes a hopeful breath as she makes her way to his side. It's only when she's a few feet away that she realizes he's alone.

"Where's your date?"

Whatever she'd expected his response to be, it did not include the cold stare he offers when he turns at the sound of her question. He blinks it away quickly enough, but as he explains that Alexis is at a Lady Gaga concert with a boy from school, she notes that Castle's voice lacks the warmth she's come to associate with him. It's more than a little disconcerting, but she shrugs off the weight of her worry and quietly suggests that they can be each other's plus one.

He nods as though he's trying to convince himself it's a good idea, but it's a nod just the same. "Yeah, and then avoid the stigma of sitting at the singles table. Yes, that would be nice. I would like that."

When Ryan skips toward them, his excitement is a welcome balm for the awkward silence that lingers, rough and unwanted, after her brief conversation with Castle, and she feels herself light up again, taking a quick picture of the groom before wrapping her arms around him. Esposito joins them a second later and she loves that her team gets the chance to be together before Ryan's big moment. Then she sees Jenny and her bridesmaids line up on the stairs, so Kate gives Ryan a playful shove and encourages him to get into place for the ceremony, Esposito following close behind.

"You know, I gotta say, I kind of envy him," Castle mutters.

She's not sure she's expected to say anything back – and perhaps he didn't mean for her to hear him in the first place – but she can't seem to let it slide. Some part of her trusts that she'll figure out what has Castle so bothered, and once she does, they can finally focus on the things she doesn't want to put off anymore.

"Well, who knows, Castle. Maybe third time's a charm."

It's a cruel joke, this time he's spending arm in arm with her. There's something reverent about the way the last of the sunlight blesses them with color as it passes through the stained glass of the church walls, and he looks down into eyes he didn't think could be any more intense. Pachelbel's Canon in D provides a soothing soundtrack to their stroll down the aisle, countering the fierce twisting of his heart when he reminds himself not to dream. He takes in the flowers, the guests, and the future that seems so certain for Ryan and Jenny, and he really does envy that happily ever after.

The fairytale has failed him twice – or he's failed it – and he sees no reason to share Kate's hope for a third. And when did she become such an optimist anyway? How does her light seem brighter just as his has dimmed?

Even when she slips her arm free from the crook of his elbow and steps toward the pew, she seeks contact, reaching her hand back with the same insistence she'd had the day they were cuffed together. Almost without thinking, he slides his palm against her and lets her lead him past the couple of guests already seated in their row, still following after all this time while his pride lags behind.

At least she releases his hand when they settle against the unforgiving wooden bench, and Castle turns his attention to Ryan and his groomsmen lined up near the altar; staring ahead will keep him from ducking his head toward the lure of Kate's perfume. She doesn't wear it at the precinct, but the scent is still so damn her, the notes of mandarin, vanilla, and sandalwood drawing him back to an undercover evening with his Ferrari and a tight black dress and music that kept his heart pounding long after the sway of her hips had left him breathless. He shifts in his seat – the timing of this particular memory is terrible for several reasons – and he senses her arched eyebrow even before he glances sideways to confirm it. The quirk of her lips suggests she's enjoying herself far more than he is, and he's grateful when familiar chords and excited murmurs announce the imminence of Jenny's arrival.

Everything will be fine. He'll smile through the vows in which he'd once believed, make pleasant conversation during a delicious dinner, congratulate the happy couple after their first dance, and then be on his way. Kate will shine strong enough for both of them, and he'll return to the loft in the comfort of the early night.

The wedding Mass is perfect for Ryan and Jenny, both grand and intimate, and Kate feels the pull of the grin that has yet to fall from her face. In the past hour, it's been threatened only by her persistent curiosity, a detective's need to solve the mystery playing out before her as Castle continues to erect a wall between them, just as hers is crumbling at her feet. She's aligned her body with his, using their shared hymnal as a reason to press closer with each new song, their voices blending beautifully even as they seem to have lost their rhythm elsewhere. Each time they sit, her hand very consciously drops to her thigh, resting so near his own and giving him every opportunity to tangle his fingers with hers; instead, his jaw tightens and her hand curls against the emptiness.

Once the happy couple has officially become husband and wife, their joy reflected by the friends and family who are now scattered throughout the church and shuffling toward the exits, Kate searches Castle's face for the creases that suggest his delight has reached his eyes. The spark that warns her of mischief to come. The tenderness that reminds her of the love he professed nearly a year ago.

None of it appears.

She forces her smile to stay in place.

"Are you guys planning on hanging out in here all night or can we head over to the reception now?"

Kate startles at Lanie's interruption and wonders how long she's been staring at Castle; if the knowing look her friend offers is any indication, it's been a while. She shakes her head clear of the disappointment she still feels and redirects the question. "We're ready, but do we need to wait for your date or will Esposito be escorting you throughout the rest of the festivities?"

Lanie isn't put off so easily. "Look at you, Kate Beckett. Trying to take the attention off of the most interesting couple of the evening…and I'm not talking about the newlyweds."

The flush crawls over her cheeks, hot and humbling, but Esposito hurries up to them then, oblivious to the not-so-subtle allegation. "Yo, let's go get some food. I'm starving."

And with that, the four of them make their way from the church to the reception venue down the street. Castle finally becomes more animated in the company of their friends, telling them about Alexis's plans for the night and lamenting the loss of his date to a teenage boy and some pop music. Kate throws her head back, laughing as she reminds him of the dozen or so Lady Gaga songs on his phone, but she's only rewarded with a quick shrug in response. When Lanie gives in to the tug of Esposito's hand, she admits that both of their dates had come down with sudden ailments during the ceremony and had decided to duck out immediately after it ended.

She's honestly glad to see that her friends have found their way back together, but as she tries and fails to catch Castle's attention, she's losing hope that she might get her own share of the romance that hangs so heavy in the air tonight.

Dinner has been cleared, the first dance complete, but Castle has yet to find a way to excuse himself from the reception. Or perhaps he just isn't trying hard enough. After all, even with the lies, selfishness, and pity fueling his anger, Kate Beckett has one hell of a grip around his heart, and leaving it behind isn't as easy as he'd like it to be.

He feels pressure against his shoulder and turns to see Kate nudging him with the back of her hand. "Brought you a drink."

Accepting it with a nod, he waits for her to sit next to him with her own cocktail. Glancing over her shoulder, he can see Lanie and Esposito still standing near the bar with a couple of other guests, Ryan and Jenny are busy greeting people along the perimeter of the room when they aren't on the dance floor or sneaking a quick kiss, and Gates and her husband have disappeared.

"It looks like we're all alone," he observes. A week ago, that comment probably would have been accompanied by a waggling eyebrow or a suggestive wink – or both – but tonight he sighs in resignation and meets her glass for a polite toast.

To what, he doesn't really know.

Still, she's smiling, and it's the same gorgeous, open smile that he's seen more in the past several weeks than in their first few years of working together, stunning in its sincerity. If he didn't know better, he'd think it held an unspoken dream, curved around honesty and love and forever.

She clears her throat and he does what he can to swallow the accusations caught in his. "Listen, Castle, I know we didn't get a chance to-"

"Come on! This is a party. Get off your asses and dance with us!"

Kate can't finish whatever she'd been about to say when Lanie and Esposito, both breathing the fire of a few tequila shots, pull them to their feet and drag them toward the people bouncing to the DJ's eclectic selection of songs. He's pretty sure he hates them a little, but he tosses his suit jacket over his chair and rolls up his sleeves as he follows their lead. And because nothing about the night is going the way he'd hoped when he'd first responded to the invitation, fantasies of all that could happen amid wedding magic dashed days ago, it's no surprise that the tempo of the music slows as they step onto the dance floor, couples already beginning to sway to the familiar ballad.

The hands that reach for him are both timid and bold, shaking and sturdy, and he's powerless to resist their pull. Without thinking any further, he tucks Kate against his body, fighting the surge of warmth that comes with the realization that she slipped off her heels before they left the table; it makes the moment more intimate, even as they're surrounded by strangers, and he closes his eyes to appreciate the way they fit.

If they never get anything else, at least he'll remember this.

She feels his entire body soften as he exhales, his breath warm against her hair, and she is relieved that he's finally willing to be close to her. Was this how it had been for him in the early days of their partnership, when he'd pushed so hard to be by her side? When he'd cracked jokes and brought coffees and only wanted to see her have a little fun? What happened during their bombing case to make them switch places? Why is she so ready to go after the one thing she wants, when he seems to have given up?

"What changed?"

His steps and his heartbeat stutter, and it's her first hint that she spoke aloud. But then he ducks his head toward hers, eyebrows raised, and she realizes he's waiting for her to repeat whatever he hadn't quite heard. Kate considers shaking it away, allowing herself to stay pressed against him until the last of the wedding guests leave and they're forced to separate, but this is too important. She needs to know what's wrong.

As they begin to dance again, she rises onto her tiptoes and brings her mouth to his ear, so much like she had when she'd taunted him after their first case.

She's far less confident now.

"What changed between us, Castle? You've been different the past few days. Distant. Unhappy." The hand holding hers tightens uncomfortably, and the one so perfectly splayed across her back freezes in place, so she rambles on before he can stop her. "And I'd worry that something's wrong at home or with your writing or a million other things, except that you're still the same around everyone else. You're only being weird with me and I just need to know why. What did I do?"

She lowers herself to the floor, their height difference pronounced in a way it's not at the precinct, and he must think she's about to walk away because he clings to her; it's an odd reaction given that he's been the one acting so damn cold. He's shaking his head against hers, even as they continue to rock in each other's arms, and she doesn't know what to do with this desperate sort of silence.

"Please, not now. I can't," he whispers as he leans down. "Please give me this one dance."

So she does.

Selfishly, she wants it at least as much as he suddenly seems to, this contact that they've so rarely shared. Their timing has always been terrible, and tonight is really no exception, but in these few minutes they can maintain their tenuous connection, agree to a truce in a war she didn't know had been waged. She rests her head on his chest, lets her fingertips trail along his spine, and waits.

But they move together too long, too perfectly, and it hurts that much more when the song ends and he pulls back to look at her, his words turning her blood to ice water.

"You're a liar."

A/N: The second half of this will be edited in time for posting tomorrow. Thanks for reading!