AN ETERNITY OR TWO
A PRE-SERIES AU
2017 HALLOWEEN BASH ENTRY

After waiting so long for the right time,
After reaching so long for a star,
All at once from the long and lonely night time,
And despite time, here you are!

Out of This World - written by Johnny Mercer and Harold Arlen

He doesn't notice until he's 35 that he looks the same as he did a few years before. Gina points it out to him, to be precise, after he'd had a new headshot taken for his book covers.

He'd heard about it, that when some people meet their soulmate they stop aging, but he hadn't met anyone like that. But when Gina mentions that his picture looks exactly the same as the one he'd taken at 30, he starts to wonder. He wouldn't have expected a huge difference in just five years, but when he puts the pictures side to side, the only difference is the shirt he's wearing.

He spends the next two years wondering who his soulmate is, and when he'd met her. He wonders if it's every woman he meets and has a relationship with, long or short, but when each relationship fizzles, he knows that he still hasn't found her.

He doesn't want just someone he gets along with. He wants that spark, the magnetic draw to someone that he's also heard about, the person with whom he's supposed to spend eternity with.

He just hopes that she stopped aging, too.

Kate mutters a curse when she hears the knock on her door. She's just put on the finishing touches of her makeup, and she grabs her heels on the way out of her bedroom, already regretting her plans.

Well, she hadn't had much of a choice, she knows. When she'd agreed to go to the stupid Halloween masquerade ball, it had been in a moment of loneliness and desperation that Lanie had jumped on. So she'd been forced to dig through her closet, and with Lanie's help, had managed to find her fanciest black dress.

"Damn, girl," Lanie says when the door opens. "You look hot. Ready to go?"

Kate rolls her eyes and steps aside so Lanie can enter. "I can't believe I agreed to come."

Lanie shrugs as she steps in front of the mirror by Kate's door, inspecting her own makeup. "You're the one who wanted to get out more," she reminds her with a raised eyebrow. "Not my fault it's Halloween."

"Uh huh." Kate finishes fastening her heels and grabs her clutch, checks that her phone and wallet are inside. She shuts off her light, and locks her door behind her with a heavy sigh. May as well get this party over with.

Rick's eyes sweep the room, looking for a familiar face, but with everyone wearing masks that cover part of all of their faces, he doesn't recognize anyone he wants to socialize with.

His fingers tug the collar of his tux, and he's itching to loosen the bow tie, maybe get rid of it altogether. But it's a Black Pawn-sponsored party, and despite being here alone, he's determined to have a good time.

He takes a glass from a passing waiter and downs the champagne in one drink.

Time to make some friends.

"How did you get an invite, again?" Kate asks as the cab pulls up to the Plaza Hotel.

Lanie pays the driver, then follows Kate out of the car. "Black Pawn sent me one as a thanks for that consulting I did a few months back."

Kate ignores the flutter in her stomach at the mention of the publisher. She recognizes Black Pawn, of course, is very familiar with one of their superstars. She wonders for a moment whether he'll be at the party, but immediately stops the tendrils of hope from unfurling. Even if he is here, there's no way he'd even notice her among what is sure to be a crowd of the busty blondes he seems to be so fond of.

She follows Lanie through the lobby and down a hallway, knows where their destination is as soon as she hears the music coming out of the large ballroom. She's grateful for the glasses of champagne being carried throughout the room, and as she downs a glass, she takes in the environment.

The large ballroom is packed, the lights low and music loud, and the guests are all dressed in their best, all holding masks to their faces. She tightens the grip on her own mask when she's bumped into from behind, and she and Lanie share a look.

"Try to relax, Kate," Lanie encourages, her head jerking towards the crowd. "Have fun. Meet someone new."

Kate suppresses the urge to roll her eyes, but when she spots the bar on one end of the room, she turns that way. Lanie had mentioned that there would be an open bar, and while she has no intention of getting drunk, she could use something just a little stronger than champagne. "I'll catch up with you later."

The flash of pale skin and short, dark hair breezing past him draws Rick's attention from the woman talking his ear off. He stops listening to the usual I'm a huge fan, and he turns his head, tries to follow the mystery woman with his eyes.

"If you'll excuse me," he says, and heads towards the bar. He follows the faint scent of cherries, and when he spots her leaning against the bar, he stops in his tracks.

Even though she's likely wearing heels, he can tell that she's tall, the cut of the long, strapless dress flattering to what's already a slim figure. Her hair is short but flattering, the slight curl of the chin-length hair complimenting her features. She's not overly made up like so many of the women here. And the way she throws back a glass of amber liquid is damn sexy.

As he gets closer, he can take in more of her features: the sharp collarbone, smooth, pale skin, a face that would look at home on a magazine cover, despite the upper half being covered by a mask.

Damn, she's hot.

"Make that two," he tells the bartender when he hears her ask for another drink. Her eyes widen slightly when she turns to him, obviously recognizing him. But, to her credit, she doesn't act how most of his fans do. She just holds her drink up in a silent salute.

"Care to join me for another?" he asks after they drink, hoping she says yes. He's drawn to her in a way that he's not used to; he'd noticed her when she'd walked past him, the confidence she exudes now a stark contrast to the rigid set of her shoulders from just a few minutes ago.

She stares in his eyes for a few long moments, almost to the point of being uncomfortable, but before he can look away she's turning from him. "No thank you, I shouldn't."

"Water, then?" He motions to the bartender, hands the woman one of the glasses set in front of them. "I'm Rick, by the way."

She takes a sip of the water, then turns back to him after a deep breath. "Kate."

Holy shit.

Holy freaking shit.

She's being hit on by Richard Castle - Richard freaking Castle - and she's actually considering walking away from him.

She'd recognized him immediately, his distinct jaw and lopsided smirk burned into her brain since the first time she'd met him eight years before. He's in the paper more often than not, usually because of exploits he has with a busty blonde or two. She isn't surprised that he's here, but why he's flirting with her, she has no idea.

"So. Come here often?"

Her attention is drawn back to him at the cheesy pickup line, and she arches a brow, ignores his his cheeks flush pink. "Really?" she says, turning back to face him, propping one hand to her hip. "'Come here often?'"

Rick shrugs, that lopsided smile coming back. "Usually I go with 'Can I buy you a drink,' but it's an open bar," he explains. He motions to her water glass. "Switching kind of early, aren't we?"

She arches her other brow. "What's it to you?"

"Oh, no reason. Just an observation."

"Well," she says, well aware that she's getting defensive, "not all of us can drink the night away and sleep it off the next day."

Rick's hands raise in a gesture of defense. "Whoa, sorry. Didn't mean to hit a nerve."

Kate glances over his shoulder, looking for Lanie, but when she sees her friends in the arms of a tall, broad-shouldered stranger, she sighs. Lanie deserves this night out. She'll stay longer, for her, so she turns back to the author in front of her. "Sorry, I didn't mean to snap." She pushes her water aside and holds out a hand. "Can I make it up to you with a dance?"

The lopsided grin re-appears. "Absolutely."

She feels great in his arms. Her hand is warm in his, and he rests his other hand on the small of her back, firm under his palm, guiding her gently as they sway to the music. They make little conversation, and partway through the second song he feels her relax and sag into him, her free hand curling around his shoulder.

He loses count of how many songs they dance to, upbeat and not, but by the time she takes his hand and leads him off the dance floor, the edges of his mask are irritating him, the collar of his shirt sweaty against his neck.

"Drink?" he asks, having to speak directly into her ear to be heard over the music and conversation of the crowd.

He doesn't miss the slight shiver when he speaks, and when she turns, her eyes are dark, dangerous. They flick to his lips, lingering for a moment before turning her gaze back to his eyes.

"How about we get out of here instead?" she says, her fingers tightening around his palm.

"Aren't you being a little presumptuous?"

She tries to keep a straight face at his look of sheer horror as they step into the elevator, a room key in his hand. After finding Lanie and telling her she'd find her own way home, she'd grasped Rick's hand again and led him out of the ballroom. He'd turned towards the elevators, explained that he had a room already.

"Well-I just thought-I didn't mean-"

She squeezes his forearm, letting her hand linger as he just stares, mouth agape. "I'm teasing, Rick." She uses his arm as leverage to bed down and take off her shoes, dangles them off her finger. "What floor?"

She follows him when he gets off on the top floor, gaping at the large suite they step into at the end of the hall. She knows who he is, that he has roughly two dozen best selling books, that he'd presumably be rich. But unless his publisher is fronting the bill for the hotel room, he must be richer than she thought.

"Rick, this is…" Her voice trails off as she takes in the dark mass below that she knows is Central Park, the lights from the hundreds of buildings surrounding it. "Wow."

"Nice, huh?" he agrees, shutting the door behind him. "Black Pawn reserved a bunch of rooms, so I figured, why not?" He strips off his jacket and hangs it in the coat closet, then turns back to her, his eyes dark with what she can only assume is desire.

She approaches him slowly, watches his eyes darken even more and his chest expand with a deep breath. Their eyes lock as she reaches for his tie, tugs the ends to loosen it, starts unbuttoning his shirt. Her fingers trail along the skin she uncovers, until she dips them below his waistband, scrapes slightly.

He jumps and grabs her hand, tugs her into him, his mouth descending to hers.

She opens her mouth on a gasp and meets his tongue with hers, her free hand gripping the back of his shirt. His hands trail down her sides to grip her hips, and she moans when his knee slips between hers.

"I want to see you," he murmurs when they part, and she leans her head back to look into his eyes. He cups her cheek, trails his thumb along the bottom of her mask.

She forces herself to take a step back, and she lifts the mask off of her face, drops it to the floor.

His hand cups her cheek again, his eyes trailing over her face, fingers tracing her cheekbones, her jaw, her lips. "You're beautiful," he says, barely a whisper.

She reaches for his own mask, and the face she reveals is the same she's seen on the backs of his books, that she briefly met years ago. "So are you." And he is; he looks like he hasn't aged a day. She curls her fingers around his ear and lifts to meet his mouth again, moaning when he nudges her backwards. "God," she gasps when her hips meet his, his desire obvious even through their clothes.

He chuckles, a low, throaty sound in his throat, and tugs down her zipper. "Not quite."

They hardly sleep that night. She dozes after their first tantalizing round, but he doesn't, just watches her sleep, her face soft, relaxed. He loses track of how long he lays there, but after some time she wakes, her long, bare limbs reach towards him, and they spend the rest of the night exploring and learning each other's bodies.

By the time they check out of the hotel he's exhausted, but at the same time rejuvenated. He hasn't connected to a woman that effortlessly in a long time, if ever, and he knows that he wants to know her even more.

"Can I see you again?" he asks as they reach the street.

She turns from the cab that the doorman had hailed for her. "Last night was fun-"

"Sounds like that's a no."

"No, let me finish." She steps towards him and grips the edge of his collar. "You should know that I'm in no place for a relationship. So it wouldn't be more than what we did."

He covers her hand with his, his thumb brushing along her knuckles. "I don't care. I had a great time last night, and I really want to see you again."

She sighs, and he gives her what he hopes are his best puppy eyes. "Fine. Do you have a pen?"

She gets cold feet a few weeks later, tells him that she doesn't have time, not even for the occasional fling. Even though she does have the time, and she enjoys every minute they're together, she'd realized while watching him sleep one night that she could see herself spending a lot of time with him.

And it terrifies her.

So she runs. But she can't run for long.

Her heart drops when she catches a case early March, with a victim - and then another one - whose scenes eerily resemble familiar scenes she'd read. She almost doesn't want to go to the party to pick him up, but she would have had to explain why. The last thing she needs are the boys teasing her about the man she'd had a fling with being a person of interest in their case.

"Mr. Castle?"

She has to keep her composure when he turns, Sharpie in hand, a smile plastered on his face. "Where would you like-Kate?" His smile morphs into surprise, then confusion, and he glances at her badge before flicking his eyes back to her face. "You're a cop?"

She tucks her badge back into her waistband. "Homicide detective, actually. May I have a word?"

She tries to get rid of him after the case, even during, but when she's lying awake in bed the night after they solve their second case together, she realized that she doesn't want him to leave. She doesn't want to admit it, but she's drawn to him like she's never been drawn to someone before.

So she accepts his offer of coffee, allows him to worm his way into her life, and eventually her heart.

"Hey, babe?"

"Yeah?" Rick pokes his head out from the closet at the sound of his wife's voice. His mind goes blank when he spots her, her long black gown slimming and elegant, hair curled in waves, looking the same as she did three years ago when they'd met - well, reconnected - at the ball. He extends his arm and wiggles his fingers, tugs her into his side when she takes his hand.

Kate turns her head when he leans in for a kiss and his lips brush against her temple. "I already did my makeup," she offers in explanation when he pouts. "So, I know we're getting ready to go…"

Rick motions to the boxers and undershirt he's still wearing. "We still have a few minutes. What's going on?"

She draws her bottom lip between her teeth, a move he knows is to stall for time. He slips his hand around hers and squeezes her palm. "Kate. Is something wrong?"

"No." She sighs and tugs his palm. "I need to tell you something."

"Okay." Warning bells are sounding in his head; she isn't usually secretive, not that she can be. He can always read her, can almost read her mind, and vice versa. But she's closed off right now, isn't giving away anything. His mind races with possibilities: she hadn't been feeling 100%, but she can't be ill?

Her hands at his cheeks stop his train of thought. "It's not bad," she assures him, but he can tell that she's nervous.

He just rests his palms on her waist and waits.

"I'm pregnant."

His face blanches at her words.

She waits for him to say something, anything, but he stays silent, his mouth agape and eyes locked on hers. "Rick?" she finally prods, lacing her fingers together at the back of his neck. "Say something, please."

He mumbles something, but it's under his breath and she has to lean closer before asking that he repeat himself.

"I didn't think it was possible."

She narrows her eyes. They'd been using birth control, not trying to get pregnant. So she hadn't questioned either of their fertility. "What do you mean?"

"I thought…" Rick takes a step back and runs a hand through his hair. "We're...I thought that people like us couldn't get pregnant."

The corner of her mouth quirks before she can stop it. "Well, you can't…"

"No," he stutters, "that's not what I mean. You know-" He points at her, then himself. "People who don't age."

"Still think we're just aging really slowly, babe."

"Not my point." They haven't met many people who have stopped aging, but those that are have all been childless. He has Alexis, of course, who was born before Kate had met him, however briefly, at a book signing. He hasn't been able to find anything official or scientific about the fertility of the Immortals, as he calls themselves, but as far as they both know, it isn't possible.

But…

She is.

"You're sure?" he finally asks "You really are?"

Her face splits with a wide grin, and she nods, poking her tongue out from between her teeth. "Yeah, I really am," she manages, laughing when he sweeps her into a hug, twirling her around before setting her down.

He cups her face in his hands and gives her a tender kiss, his mouth moving lazily over hers as his thumbs caress her cheekbones. "I love you," he breathes when they part.

She smiles and brushes her mouth against his. "I love you too. Now, finish getting dressed." She reaches down and pinches his ass, giggling at his yelp. "We have a party to go to."

-FIN-

A/N: based off a prompt generously provided by CastleFicPromoter: Pre-series, Castle and Beckett meet at a mutual friend's Halloween party and hook up. Any mistakes are mine. As usual, thank you for reading!