Disclaimer: All things "Castle" belong to Andrew Marlowe and ABC.

Author's Note: This scenario popped into my head and I'm running with it. Getting aboard the AU train…

Accidentally in Love

Chapter 1

Stupid.

This whole idea had been stupid.

Kate blinked back tears as she stared blindly at the chocolate cupcake she'd just bought. Who was she kidding? What on earth had made her think that getting herself a birthday cupcake would make her feel better, make this disaster of a birthday seem less so?

She no longer remembered exactly what she'd thought—or if she'd thought at all, really. She'd returned home after her shift had ended and changed out of her uniform but the thought of spending the rest of the evening alone in her solitary apartment had abruptly struck her as too miserable a thing. She'd started to feel suffocated by the very silence she usually appreciated about her apartment, as if the very lack of company, of anyone else there, were pounding at her with reminders of how alone she was.

So she'd grabbed up a coat and gone out, seeking the noise, the people, the traffic that was so much a part of New York City life, so far removed from the structures of her own quiet, orderly life.

She was generally fine. Really, she was. She didn't need anyone else to take care of her or make her happy or any of that. She was fine on her own, had been for years. Independent, self-sufficient. Her life was neat and quiet and organized, just the way she liked it, and she liked her job. She had finally been transferred into the Homicide division a few months back and was one step closer to her goal of becoming a Homicide detective. The detectives whose team she was on were good cops and her captain was great, a real mentor.

But today had been a bad day.

She'd gotten called out to a crime scene for a body found in an alley and had spent more than an hour dumpster diving trying to find the victim's ID or any other potential clues but had come up empty-handed and it had been her counterpart, Maclaren, who had come up with the victim's ID and a gunpowder-stained plastic bottle that had been used as a poor man's silencer. And to add insult to injury, it had started to rain while she'd been in the dumpster so she'd been thoroughly soaked by the time she was allowed to climb out of the dumpster.

It was the nature of the job that there were going to be days where nothing came up right but today, of all days, she couldn't seem to hold back her emotions.

It was no wonder that the very emptiness and solitude of her apartment had slapped her in the face when she'd finally returned home so she'd been driven to leave it and just walk. She had no particular destination in mind; she just wanted to be out, surrounded by noise and people.

And then she'd come across this place, a tiny little bakery specializing in cupcakes, and she'd been swamped with sudden memories of the last birthday she'd spent with her mom and dad. Her 17th birthday in her senior year of high school. She'd had plans with her friends and had returned home to their apartment just in time for her curfew to find her parents waiting. And her mom had brought out what she called a birthday cupcake (since Kate had declared for years that a birthday cake was for little kids) and insisted that Kate sit down at the head of the table and had put one of those single candles in the shape of the number 17 in the cupcake and lit it. And her parents had sung "Happy birthday" to her and her mom had insisted she blow out the candle and make a wish while doing so.

Kate hadn't made a wish as she blew out the candle.

She'd been irritated and had barely tried to hide her urge to roll her eyes at her parents' cheesy (as she'd thought) insistence on celebrating her birthday like this as if she were still some little kid, her mom's telling her to make a wish as if Kate believed in things like wishes made on a birthday candle coming true.

Kate felt a lump of painful emotion in her throat, unwanted tears pricking at the back of her eyes.

She rather wanted to shake her arrogant 17-year-old self. How could she have been so self-absorbed, so determinedly displeased with her parents' entirely natural desire to celebrate her birthday?

She hadn't known—no one and nothing had told her it would be the last birthday she'd spend with her mom, since her 18th and 19th birthdays had happened when she'd been at Stanford. The last birthday she'd had with her mom and she hadn't appreciated it at all, had barely managed to crack a small smile and not with any enthusiasm at that.

She'd been such a blind, self-centered idiot, she thought, with all the blindness and self-centeredness that generally characterized teenagers, but knowing that she hadn't been an outlier for her age didn't make it feel any better now to her 25-year-old self.

Now, when she knew she would give up everything she had and then some for just one more day, one more hour, with her mom. Now, when she wished with her entire heart and soul that her mom was still here, still with her.

But her mom was gone. And her dad…

She couldn't think about her dad.

Kate gave up on eating the cupcake she had so stupidly bought. Her throat was so tight she thought she might choke if she had to force down a bite of anything.

And tears were welling up in her eyes and she absolutely refused to cry in public. She wouldn't cry, couldn't cry, where people could see her break down.

She leaped up out of her chair and turned to leave, to flee back to her safe, solitary apartment, only to crash into someone, the cupcake she'd been about to discard smashing onto the man's jacket.

Kate forgot her grief and her tears in the more immediate dismay and embarrassment as she lifted her horrified eyes to see the face of the man whose jacket she'd just ruined.

Shit! Oh god oh god, why did the universe hate her today? And where was the hole in the ground that must have just opened up so she could jump into it and never show her face again?

It was Richard Castle.

Bad enough to have just crashed into anyone and crushed her cupcake onto their clothing but to crash into Richard Castle, of all people, like this and make such an ass of herself!

She'd just ruined Richard Castle's jacket, an ugly clump of vanilla frosting and chocolate crumbs smeared across what looked like an expensive, formal jacket.

"Oh shit, I'm so sorry. It's my fault; I wasn't looking where I was going and I just—I'm so sorry!" she blurted out in a rush of embarrassment, heat flooding her face.

Bad day. Very, very bad day.

Richard Castle's eyes were wide with surprise as his gaze flickered between her face and his jacket and then he blinked and smiled. Smiled? "I guess cupcake frosting doesn't match with this jacket. Good to know."

His voice sounded amused, not angry, but Kate was jolted out of her momentary paralysis and rushed to grab some napkins, tossing out her now defunct cupcake, and tried to make an awkward dab at the smear.

"I can do it," he quickly reassured her, reaching out to grab her wrist and she felt an insane little prickle of reaction from the heat of his touch even through her jacket sleeve. She was losing her mind, she decided, this one last indignity tipping her over the edge. That was all. She surrendered the napkins to him and he made a game attempt at removing the frosting, succeeding for the most part but there was still an unsightly and very obvious stain on the jacket.

"I'm so sorry," Kate said again, feeling even more like an idiot, if such a thing were possible. "Can I at least make it up to you by paying for the dry cleaning?"

He finished dabbing at his jacket and tossed the soiled napkins into the trash. "No, thank you, that's really not necessary, Miss—er—"

"Kate," she finished for him. She normally introduced herself as Beckett but she wasn't feeling at all like her usual, competent Officer Beckett self.

"It's really not necessary, Kate," he repeated. "I'm a father. Trust me when I tell you that I've had much worse things staining my clothes than a little bit of frosting so don't even worry about the cleaning bill. It's nothing. Oh and I'm Rick, by the way."

Kate bit the inside of her lip and didn't mention that she knew his name—no need to sound like some crazed fan-girl and look even worse than she already did—and shook the hand that he offered, amazed at how good-humored he was being about this. He was rich and famous, a celebrity, whose exploits were popular fodder on Page Six. She was hard-pressed to imagine that other celebrities would react with such equanimity and graciousness to having what must be an expensive item of clothing ruined through no fault of their own. It was the sort of thing that would displease anyone. And his self-deprecating quip about having had worse stains on his clothes from being a father—a statement that brought to mind baby food or vomit or worse, she supposed—had managed to ease her guilt and her embarrassment a little. "Nice to meet you," she said automatically and then had to smile in spite of herself at the sheer ridiculousness of the greeting under the circumstances.

Richard Castle—Rick—god, was she actually on first name terms with her favorite living author now?—smiled as well. "Now that that's out of the way, your cupcake was wrecked so can I buy you another one? I should have been paying more attention to where I was going too."

"Oh no, that's all right," she demurred immediately and too forcefully, some of her almost-forgotten emotions at the thought of eating the cupcake returning to her and leaking into her voice. "Really, it was my fault and I wasn't going to eat the cupcake anyway."

"Is something wrong? You look—you had tears in your eyes. I couldn't help but notice," he ventured, his tone gentle. "Did you buy the cupcake to try to cheer yourself up too?"

Too? He'd bought cupcakes to cheer himself up? And he'd noticed the tears in her eyes. (Of course he'd noticed. He wasn't blind and she'd been right in front of him.) "Too?" she blurted out unthinkingly.

He winced a little. So he hadn't meant to say that. "I'll tell you mine if you tell me yours," he offered with what seemed like an attempt at glibness. A way to deflect, she thought, because such an offer would normally invite refusal. And then he added with a little shrug and a face that managed to be self-deprecating, "I know we just met so you don't have to say anything. I'm just being nosy so feel free to tell me to butt out. But if you want to talk about it, if you think it might help," he shrugged a little, "I've been told I'm a good listener."

She opened her lips to refuse—she wasn't someone who talked about her life, let alone her emotions, at the best of times, with anyone, let alone a stranger and Rick Castle was a complete stranger, since getting a book signed by him more than a year ago didn't count—but then she met his eyes, filled with kindness. The author pictures on his books really didn't do justice to his deep cobalt blue eyes at all, she thought irrelevantly. And she abruptly found herself changing her mind. Why not tell him just a little? It wasn't like they would ever meet again and there was something freeing about that. She didn't have many friends; she was friendly enough with her co-workers but there was always a distance between them because they were almost all men and she wanted to be taken seriously. Her only real friend these days was Lanie Parish and she had only known Lanie for about a year now, since Lanie had started working at the ME's office. The last person she had considered a real friend, whom she'd trusted, had been Royce and he was gone, had dropped her the moment she'd been promoted and been transferred to the 12th precinct and then she'd heard that he'd retired the next year.

There was no one else, certainly no one she would ever talk to about her mom or her dad, and with Rick Castle, she didn't need to wonder what he would think of her or dread the pity in his eyes because she doubted she'd ever see him again so what did it matter if he pitied her?

He was a multimillionaire celebrity and she was just a cop. Tonight's literal run-in had been the barest chance, one of those random events that happened in a city of so many millions of people crammed on a small island, and would never happen again.

So what did she have to lose? She'd wanted to escape the solitude of her apartment for other people and now, one of those other people had offered to listen. And the fact that he was her favorite living author made her feel oddly as if she already knew him. She knew his author's voice, knew the way his mind tended to work in his stories, so he wasn't a total stranger in that sense either. In a weird way, she felt as if she'd known him for years.

"It's a long story," she answered before moving to sit back down in the chair she'd been sitting in before.

He settled into the chair opposite her, placing the box he'd been carrying with the two cupcakes he must have bought on the table. "I have some time. It'll be a pity party for two," he said with a lightness that in anyone else, she would have felt was jarringly inappropriate but somehow, in him, maybe because his eyes stayed soft and sober, felt oddly comforting. And she was a cop; she knew all about the use of humor to stave off grim realities.

She answered with a faint smile. "Well, the short version of my story is that I had a terrible day at work, today's my birthday and I'm spending it alone because my closest friend in town has to work, my mom is dead, and my dad's a drunk," she finished, the harsh word seeming to sting her own tongue for saying it.

Her dad was in rehab, a voice in her mind spoke up, getting sober again or trying to.

Still a drunk, another part of her mind argued back. She couldn't hope in her dad's sobriety, rely on it lasting. Not again, not anymore. It hurt too much to hope and be disappointed. All the broken promises, all the lies. It all hurt too much.

"I'm so sorry," Rick responded quietly.

They were commonplace words, the words everyone said when they heard about her mom, but something about the way he said them, the expression on his face, made the trite words seem sincere. Made them mean more than they had from almost anyone else in years.

Maybe it was because he didn't follow them up with any well-meaning but unhelpful platitudes about time healing all wounds or about her mom being at peace now or about everything happening for a reason (which infuriated Kate). He said nothing else and she found herself thinking that he appeared to have the rare talent in writers of knowing when more words wouldn't help.

And even though she hadn't intended to tell him anymore—had already said more than she would have believed she would—she found herself adding, "My dad's in rehab now so…" She trailed off, not quite able to say anything to indicate that her dad would end up successfully conquering his addiction. She couldn't hope.

But she couldn't put that into words.

His expression eased a little. "I hope it helps."

Her heart pinched. She did too but she didn't dare let herself believe that.

Her dad had called her to wish her a happy birthday and mention that he should be finishing with rehab in a matter of weeks and then he would see her again. She'd felt curiously numb as she answered, with careful politeness, that she would like that and wished him luck—an awkward thing to say but all that came to mind. And the entire conversation had been awkward; she and her dad no longer knew what to say to each other.

She made an attempt at a smile that she suspected ended up looking more like a grimace. "What's your sad story?"

He grimaced a little. "After yours, mine doesn't seem worth telling."

She raised her eyebrows at him slightly in a mildly interrogatory fashion. "No evasive maneuvers. We had a deal, didn't we?"

He gave in with a small moue of resignation. "My ex-wife was supposed to come out for Thanksgiving to spend some time with my daughter and my daughter's been looking forward to it for weeks. But then my ex-wife called tonight to say that an audition came up and so she won't be coming after all." He paused, a scowl creasing his brows and making his eyes darken to midnight blue with anger, and then added, bleakly, "My daughter's going to be heartbroken and I'm going to be the one who has to break her heart."

She'd known he had a daughter from the author blurbs of his books (the single sentence stating that Richard Castle lived in New York with his daughter) but she also knew, from interviews he'd given and mentions of his publicity events in the papers, that he never mentioned his daughter in public, was apparently very careful about protecting her. She was a little surprised that he was mentioning her now but then, she supposed the relative anonymity that had allowed her to talk to him also allowed him to mention his daughter. And he didn't know she knew who he was so his instinct to protect his daughter from any publicity wasn't kicking in. "How old is your daughter?"

His expression softened immediately, lighting up with a small smile at the mention of his daughter and something inside her chest went soft. Oh, wow. She'd had no idea that Richard Castle was such a… well, a dad. It was such a… normal, humanizing thing to find out. It occurred to her belatedly that he must have full custody of his daughter, which was unusual.

"She's 9 and she's great." His expression turned grim and a little sad. "How am I supposed to break her heart? I can't stand thinking about it." He gestured at the box of cupcakes. "That's why I got these. Thought they might help cheer her up." He gave a little, unamused laugh. "Cupcakes to heal a broken heart. Stupid idea."

Kate thought about a little nine-year-old girl having her heart broken because her mom thought an audition was more important than spending Thanksgiving with her daughter. (Rick hadn't said that in so many words but Kate could read between the lines to get at the implication.) Her heart hurt and it occurred to her that she had been lucky too. She had her memories of her mom and remembered perfectly well that her mom, as busy as she had been, had always been willing to drop everything when Kate needed her, just like she had when Kate had needed to get her tonsils out.

"No, not stupid," Kate finally said. "People do things like that when they want to cheer other people up and as they say, it's the thought that counts." She paused and then added, on an impulse that surprised her, "It sounds like you're a good dad."

She meant it. It had never occurred to her before, not that she'd ever thought about it, but it surprised her. From the mentions of him in Page Six, from his reputation as a charming playboy, the bad-boy author and celebrity-about-town, she would have pegged him as being rather frivolous, irresponsible, and self-centered. But from what she'd seen of him tonight, which she suspected was closer to the real Richard Castle than anything in Page Six, he was much more than that. He was… nice. Lame as the word was, it applied. He'd been kind and gracious about his ruined jacket. Compassionate without pity or condescension at her story. And yes, he appeared to be a good dad. One who was so troubled over his daughter's hurt feelings that he went out and bought her cupcakes preemptively to cheer her up. He couldn't actually be that frivolous or irresponsible or self-centered after all.

He looked surprised but didn't quite smile. "I try to be and I lucked out with my daughter."

He might be talking about his daughter but he was still not mentioning her by name, Kate noted. He was protective of his daughter. Even to her. Which was as it should be. Yes, Richard Castle was a good dad.

"I think… kids are more resilient than we sometimes give them credit for being," she offered in reassurance, not quite sure of what to say. She couldn't absolutely assure him that his daughter would be fine; she didn't know that.

"I hope so."

"You can still make it a good Thanksgiving for her. I always think I remember the food best about Thanksgiving." Melancholy twisted in her chest as she thought about Thanksgivings growing up, about her younger self helping her mom in the kitchen, about going over to her grandparents' house for Thanksgiving when she was little.

He smiled, a small but real smile. She felt a ridiculous little butterfly take flight inside her chest in reaction. Richard Castle was a good-looking man at any time, even when he was upset or worried. But when he smiled, his blue eyes becoming brighter…

She'd known he was charming from the book signing she'd gone to, when he had directed a smile at all the fans who had shown up, but she realized now that his smile then had been an impersonal one, something of a persona he had assumed for publicity. His smile now was different, real, not about a projection of charisma—and somehow that made it even more potent.

"That's something at least. I was already planning on going all out for a Thanksgiving feast."

He cooked? On the other hand, in Manhattan, it was easy enough to get the entire workings of a Thanksgiving feast delivered, ready to heat and serve, she reminded herself and bit back the question, her curiosity. He might be her favorite living author and she was finding the idea of learning more about him to be surprisingly thrilling but she was absolutely not going to sound like a fan-girl.

She gave him a small smile. "That's always the first step so there you go."

"Thanks, Kate. This is… nice of you, to listen. You didn't need to do that."

"You listened to me too."

He shrugged a little. "I only wish there was something I could say to make things better for you."

"It's okay, Rick," she added his first name after an almost imperceptible pause. She didn't feel comfortable calling him by his first name but she didn't have a choice since he hadn't told her his last name in what could have been a bid to protect his own privacy. "I really am usually fine. It was just a bad day today. You caught me at a low point."

He met her eyes. "Still. It was… nice to have met you, Kate. I need to get back home to my daughter since she's with a babysitter right now."

"Oh, right, of course," she agreed and stood up, along with him. "It was nice talking to you. I really am sorry about your jacket. Are you sure you won't let me pay for dry cleaning?"

"Don't worry about it," he said dismissively. "I guess I'll see you around. Have a good night, Kate."

"Bye, Rick." Kate hesitated and then reached out her hand and he shook it. Kate sternly ignored the little tingle of reaction that went through her at the touch of his hand, the brief clasp of his fingers. So he was attractive, so what. It didn't matter. He needed to get home to his daughter. Nothing was going to happen.

Anyway, she was probably never going to see him again. They lived in different worlds, after all, multi-millionaires didn't exactly move in the same circles as cops.

So Kate told herself as she strode briskly away from the bakery, refusing to glance around to watch him leave. She made it a block and half away before stopping at a crosswalk to wait for the signal.

"Kate!"

She turned to see Rick jogging towards her, swerving around other pedestrians.

He was panting a little as he came to a stop in front of her, handing her a small box that she accepted automatically. "Here. Happy birthday, Kate."

She glanced at the box. He had bought her a cupcake. A birthday cupcake. She suddenly wasn't sure whether she wanted to laugh or cry. "Thanks," she managed to say.

"Take care of yourself, Kate." He paused and then he abruptly bent forward as she froze and then he was brushing the lightest of kisses on her cheek, his lips just grazing her cheekbone.

Her face flared with heat, her cheek tingling, her brain abruptly blanking, and she was left momentarily unable to do anything but gape a little as he drew back and then left.

Richard Castle had just kissed her cheek—she could still feel the faint lingering warmth like an imprint on her skin.

She looked down at the box, peeking inside to see that, yes, he had bought a chocolate cupcake, just like the one she had ruined on his jacket.

He had bought her a birthday cupcake. She felt herself smiling before she'd realized it, a tendril of warmth sprouting up inside her chest. It was… sweet of him.

Maybe, this wasn't turning out to be such a terrible day, after all.