Loosely based on a prompt from Lou (original prompt at the end). Thanks Andy for the beta.

Disclaimer: If you recognize it from the show, it's safe to say it's not mine.

Literal Interpretation

Kate is sitting at her kitchen table in leggings and a baggy red night shirt, sipping coffee and browsing through the newspaper, when there's a knock at her door. She glances at the clock, furrows her brow. It's just after eight on a Saturday morning and she's not expecting anyone, so it shouldn't surprise her at all, really, when she opens the door to find…

"Castle?"

She huffs a sigh. They haven't spoken since their completely pointless fight last night by the tower of Nikki Heat novels. The words still flit through her mind.

There really wasn't enough to the character of Nikki Heat for more than one novel anyway.

She just needs a better writer.

And it's stupid, so stupid, because Castle is a fantastic writer and Kate is flattered that he chose to write a book about her and she is going to miss having him around at the precinct and she has a feeling he'll miss it too. And somehow, their respective inabilities to ever actually talk about anything devolved into that ridiculous argument.

It was both of their faults, she knows. But she finds she's still mad at him. Well, maybe not mad. But irritated. For reasons she doesn't really want to consider.

"Hey," he greets, the syllable slicing through her thoughts.

"What're you…" Kate cocks her head, "…doing here?"

His response doesn't answer her question. "You told me to do whatever I wanted."

Her fingers curl around the edge of the door, her other hand resting on the frame; bracing herself and very clearly not allowing him in. "What?"

"At the launch party," he clarifies. "You said 'do whatever you wanna do.'" Castle curls his fingers into air quotation marks as he speaks.

"And…?" she asks, impatience growing.

"Well, here I am." He says it with a shrug and a smile, as though it's obvious.

"Yes, I'm aware," Kate deadpans.

Castle wiggles his eyebrows suggestively as he speaks again. "To do what I want."

Oh, no. He can't possibly mean…

But the way his heated gaze roams her body leaves absolutely no doubt as to his intentions.

When she told him last night to do whatever he wanted, she meant 'take the certain British secret agent offer.' She definitely didn't mean, well, this.

"Oh, really?" Kate drawls, cocking an eyebrow in that way she's noticed he finds irresistible. His eyes darken almost imperceptibly as she does so.

He may want her (and yes, she wants him too, she's finally admitted, at least to herself) but she's not about to make this easy for him. Not when he's shown up at her doorstep all scruffy, hair disheveled, looking sexy as hell and thinking he can just barge in and…what? Take her right there on the couch?

Her stomach flutters at the thought; Kate resolutely tamps it down.

Castle nods eagerly, excitement twinkling in the piercing blue of his eyes.

"And what's that, exactly?" Kate challenges.

"I wanna take you out," he answers, and the mischief falls from her face in time with the air leaving her lungs. He wants to…

"What?"

"On a date," Castle clarifies. His eyes are bright, hopeful, filled with something she can't quite identify. Whatever it is, it's far too soft to be coming from the man who's spent the majority of the last few months trying to get her into bed.

"Tonight, if you're free," he continues. "I got us reservations at this cute little Italian place in Tribeca. I've been going there with Alexis since she was little. It's owned by this older couple from Tuscany and the food is authentic and the wine is amazing and it's small and quiet and we can be…"

Kate quirks an eyebrow again, in disbelief this time as she interrupts his nervous soliloquy. "You already made reservations?"

"Well, I mean, I wanted to make sure we'd get a table," he hedges, and she's pleased to see that he's fairly well thrown off his game and at least a little bit chastened. She'll never admit the satisfaction she feels over the fact that she can completely disarm this supposed playboy extraordinaire.

Kate has a few other ideas about how she could render him speechless, but those will have to wait. In the meantime, she's going to have a little fun with him. This. Whatever.

"And what if I say no?"

"Well then I guess I could…I mean, I could cancel. Or take Alexis instead. Or…" he stutters to a halt. "You're saying no, aren't you?"

Kate releases her hold on the door and door frame to cross her arms over her chest. "I'm saying you seem pretty sure of yourself."

"Yeah well," he trails off, and she can see what remains of his bravado crumbling. His face falls, his eyes lose their spark. "False confidence seemed like the best option."

Oh. Oh.

He expects her to say no. Well, now she definitely knows how to throw him off his game.

"Sure, Castle," Kate answers, the edges of a smile tugging at her lips. "You can take me to dinner tonight."

He shows up right on time, wearing dark jeans and a black jacket over a deep red shirt. The top three buttons are undone, giving way to the smooth skin over his sternum, and Kate's gaze lingers there for a moment too long to be considered innocent.

"Hi," she greets, eyes finally finding his face. He shaved, she notices, tries to suppress her disappointment. He looked really good this morning with a couple days of scruff peppering his jaw. But he looks nice now too, clear blue eyes taking her in with a combination of shyness and something she almost thinks resembles adoration.

"Hey," Castle answers.

His eyes follow the vee neckline of her dark purple dress, down to the parentheses of her waist, the soft curve of her hips. The dress flares out from there, the hem falling midway down her thighs. Short enough to be alluring but long enough to be classy. She's paired it with silver heels to match the silver necklace nestled between her breasts.

Kate spent more time than she's willing to admit styling her hair, ringlet curls pulled halfway back, bangs framing her face; it's not entirely unlike her hairstyle from the book launch party last night. She noticed the way he looked at her, did her best to recreate it. Her eyes are lined darkly too, smoky, and her pink glossy lips split into a smile at his next words.

"You look really nice."

"Thanks," she murmurs, wills the heat to stop flaming her chest, her neck, her cheeks, but it's no use. "So do you."

"I brought you these." Castle extends a bouquet of flowers, brightly colored carnations interwoven with delicate baby's breath.

"Thank you," Kate answers again. Their fingers brush as she takes the flowers, leans in to flutter her lips against his cheek in a whisper of a kiss. She hears his quick intake of breath, traps her lower lip between her teeth to suppress a smile as she steps away and crosses to the kitchen, busies herself with digging out a vase, filling it with water and arranging the flowers inside.

She sets them on the kitchen counter, strides back into the living room to find Castle perusing her apartment but – shockingly – keeping his hands to himself. The click of her heels on the wooden floorboards alerts him to her reappearance and he turns, offers a tentative smile.

He's nervous, Kate realizes with a jolt. Really nervous.

"Ready?" Castle manages unevenly, and, wow. She's never really seen him like this. Arrogant and confident seem to have been replaced with hesitant and insecure. It's…refreshing. And it helps her manage her own nerves, the flutters of anticipation. He may be uncertain of how tonight will end, but Kate already has a pretty good idea.

She grabs her coat, shrugs into it as she picks up her clutch. "Lead the way."

Dinner is a surprisingly down-to-earth affair. Both the hostess and the waiter greet Castle by name, and Luca and Gianna (the owners, Castle explains later) come out to chat with them for a few minutes.

They're seated at the table in the back, out of the way of prying eyes. They order a bottle of wine and nibble on bread swirled in a rich, peppery extra virgin olive oil as they wait for their meal.

The nervousness dissipates once they fall into an easy conversation. They spend so much time bickering at the precinct that Kate sometimes forgets that Castle is actually really easy to talk to; light-hearted, knowledgeable, well-read, sees the world with an innocence and optimism that she can scarcely imagine anymore.

They talk about Martha and Alexis, acting ventures and high school drama. Castle learns a bit about her father; that he's a lawyer too, that he likes to fish, and owns a cabin upstate. They manage to ignore the giant elephant in the room – the uncertain future of Nikki Heat and a certain British secret agent – but the conversation flows so naturally that it's easily forgotten.

They smile and laugh all the way through dinner, through the full bottle of wine and the complimentary dessert that Gianna insists they share. It's intimate, eating off the same plate (thankfully he doesn't try to feed her, Kate thinks with a breath of relief), but comfortable at the same time.

Castle pays the bill, helps her into her coat, guides her out of the restaurant with a hand on her lower back. His palm is wide, fingers spread, and she can feel the heat even through two layers of fabric as they step out into the night.

The restaurant isn't far from her place and it's a fairly nice evening so Kate decides she'll forgo a cab.

"Can I, uh, walk you home?" Castle asks nervously.

Kate turns to him, surprised. She fully expects some kind of innuendo, expects that he's already assumed he'll be coming home with her, and she's having trouble reconciling tonight's softer, more sincere, more real Castle with the Castle she's known for the past few months.

Except – the tiny voice in the back of her head reminds her – she has seen glimpses of this Castle before. Every time he talks about Alexis, for example. The night she told him about her mother and he proved that he's capable of being serious and empathetic. Other scattered moments over the course of the last seven months; moments that are becoming more and more frequent. It's made her wonder how much of the playboy thing is simply an act.

"Sure," Kate murmurs with an easy smile.

Castle extends an elbow and she loops her arm through it so naturally it almost scares her. Truthfully, this entire evening probably should scare her a little more than it does. But she's having a nice time, so she pushes the thought away, focuses on the warmth and breadth of his body next to hers.

They walk most of the distance in silence, Castle stealing sidelong glances at Kate while she determinedly keeps her gaze pointed forward. Their arms are still intertwined, their strides match, and they settle into an easy rhythm despite this new precedent of space between them. Or, well, lack thereof. The top of Kate's forearm brushes his side while the back of his elbow rests against her waist, and their shoulders brush with every other step. It feels familiar, normal.

"Thanks for dinner," Kate murmurs as they come to a stop outside her building. She detangles their arms, turns to face him.

"Thanks for coming out with me," Castle replies, and the honesty and gratitude in his voice knocks the wind out of her a little bit.

She smiles up at him, demure, and his gaze flickers to her lips, back to her eyes. His are dark, liquid and dancing with the colors of the streetlights. The nervousness seems to have resurfaced but she can see the attraction and desire there too. He's not the only one who's observant, who has spent time learning the nuances of the other.

He opens his mouth to speak again but she beats him to it. "You wanna come up?"

Kate's proud of how steady her voice is. How sure. She may have spent the last seven months pretending not to like him, pretending not to want him, but she's not falling for her own act anymore. She hasn't been for a while. He wants her, she wants him, and if their chemistry while fully clothed is any indication, she knows it's going to be amazing.

"Really?" From the look on his face, she's pretty sure that's not the response he intended to give.

Kate smirks, raises an eyebrow.

"I, uh…" Castle stammers, falls silent for a beat too long.

She opens her mouth, ready with a retort, a challenge, but the words die on her lips as he finally speaks.

"I want you," he utters, and just hearing the words fall from his mouth in such a low voice sends a shiver rippling through her. "You know that. I don't think I've been…subtle."

She laughs, can't help herself, but it serves to break the tension. "No, you haven't."

Her response elicits a not-really-apologetic smile before his expression grows serious again. "But I don't just want you for tonight."

Now it's Kate's turn to be caught off-guard. "What?"

"I don't know what's going to happen with Nikki Heat or this other offer," Castle explains. "But last night my agent told me to sleep with you and get you out of my system so I could move on, and I realized that's not what I want. I don't want you out of my system. I very much want you in it."

Do whatever you wanna do.

Here I am. To do what I want.

Kate is staring at him with what she's sure must be a stunned mixture of shock, apprehension, and desire as he speaks. She forgets to blink, forgets to breathe, forgets everything except the sound of her favorite author telling her that he wants her. Truly wants her. For more than one night.

She definitely didn't see this coming.

"I, uh…" she stammers, at a complete loss for words. Sometimes she forgets how easily he can throw her off balance, too.

But the best defense is a good offense, so before he can react, she catches his face between her hands, rises up and captures his mouth. His lips are soft, cool thanks to the evening air, and they respond in kind. His arms wrap around her, tug her flush against him, and she retaliates with a nip of her teeth at his bottom lip before her tongue comes out to soothe it. Castle captures her tongue before it can disappear and Kate parts her lips, grants him access. One of his hands has found its way beneath her jacket and her fingers are woven into his hair, holding him in place while he pulls her infinitely closer.

Somewhere nearby, someone wolf whistles and they jerk apart in surprise, laughing awkwardly. Right. Public sidewalk. Not the place for a makeout session.

Castle pulls his hand from beneath her jacket and she allows hers to fall to his shoulders; Kate rests her forehead against his, eyes fluttering closed again as she focuses on steadying her breathing, regaining her balance. Her heart is pounding, arousal coursing through her veins, and wow. The man has a talented tongue. She'd like to see what else he can do with it, if he would just come up to her…

Oh. Right.

His horribly-timed, beautiful, perfectly imperfect confession that she still hasn't really answered. She doesn't know how to answer it. She didn't ever consider that this would be more than a one-time thing, and she can't decide if she wants it to be. Well, that's not entirely accurate. She's completely okay with the sex aspect of it being more than a one-time thing. But he makes it sound like he wants to keep dating her, and she's really not sure that's such a good idea.

"I'll come up," he murmurs, saving her the need to organize words into an actual sentence right away, "if you let me take you out again soon."

Kate leans back in Castle's arms just enough to meet his eyes with her own. They're impossibly dark, intense, layered with arousal and something she's not willing to put a name to. But he looks so hopeful, so sincere, and the taste of their kiss lingers on her lips, begging for more. All of her defenses, every carefully orchestrated excuse she's ever come up with...all of it crumbles away. And before she can reconsider all the reasons this is a terrible idea, the answer is tumbling from her mouth.

"Cook me breakfast tomorrow morning, and you've got yourself a deal."

END

Prompt: Scene at the book launch ends with her saying "do whatever you want, you always do anyway" and he says "fine," takes her hand, leads her out to a convenient coat closet, and does her.

Obviously I adapted it a little bit because – well – this was what my brain came up with.