A/N: So I haven't been writing (or reading) much the last couple of months due to a lot of RL stresses but here is a story I've been messing with on and off most of the summer. I've been trying to avoid spoilers for the new season so there shouldn't be any for anything past Watershed.

"Hey, Castle."

She greeted him with that deep, throaty voice she sometimes had early in the morning after too little sleep. But he could picture the smile on her face as she pressed the cell phone to her ear, her eyes still closed in the darkness of her Washington D.C. apartment.

"Good morning. Did I wake you?"

"I need to get up anyway," Kate allowed. With an audible snort, she added, "Briefing in an hour."

"These briefings seem anything but brief."

"Hhrm," she muttered in sleepy agreement.

He heard the rustle of sheets over the line as she extracted herself from the bed. In his mind's eye, he followed her into the kitchen as she headed straight for the coffee maker.

"Lots of paperwork, too," she added. "Spent all day yesterday doing nothing but going over case files."

"Are they still hazing you with the paperwork?" he asked, frowning. Her new co-workers dropped their case files on her as the newest hire to finalize paperwork. She'd mentioned it before, casually, as mostly a joke. But he worried about Kate being taken advantage of for her dedication and need to prove herself.

"I am the most junior person on the task force."

The way she said it, it sounded as though she were repeating something she had been told time and time again. But the thought of Kate's talents being wasted on paperwork still irritated him.

"But today should be interesting," she added. "Got a new case assigned to me yesterday."

"A new case? That is exciting," Castle said, mustering more interest than he felt. He knew she could tell him nothing about the case, no matter how unusual or complicated it might be. Federal rules prohibited her from discussing such matters with civilians or even outside agencies like the NYPD.

While part of him had wanted to push her boss so he could shadow her as he had done with the NYPD, Castle did not want to make waves for her at the new job. Plus he doubted that he'd have as much pull with the United States Attorney General as he did with the mayor of New York City.

"Not really," Kate said. "Not a murder. Bank robberies."

Castle raised an eyebrow as he nodded to himself. "Bank robberies can be interesting, as I well know from personal experience."

He heard the hesitation in her voice as she responded, the sound of her coffee maker peculating in the background. "Not like that. Insider robberies - funds going missing from certain banks. No guns or fake doctors, just a lot of bank account numbers and discrepancies in funds."

She sounded disappointed in the assignment, but Castle knew it would be good for her. She had already spent so much of her life in amongst the worst of what humanity had to offer - blood and death and pain. Part of him liked the idea of her spending large portions of her new job behind the safe confines of a federal desk and a fancy computer screen.

"How's Alexis?" she asked.

Through the phone line, he could hear the tell-tale sounds of clothing rustling as she pulled on a business suit. At this job, she always had to wear a suit, always had to look professional. He had even spent a day with her as she shopped in D.C. picking out new clothes. Her cute jackets and slacks had been banished to the back of her closet. A dark charcoal grey number which fit her perfectly was now the most scandalous suit she owned because it wasn't black.

"She's good," he answered, recalling his conversation with his daughter the night before. "She's enjoying studying the rainforest, but I think she's looking forward to electricity and indoor plumbing."

Kate laughed at his joke, a genuine laugh, and for just a moment, Castle felt time slow down and stop. In the months since she'd taken this new job, he rarely heard her laugh. In their quick phone calls in the mornings and evenings when she had time, they danced around each other, neither really knowing what to say or how to act. It was sad, frightening, even. But if nothing else, it gave him the incentive to enjoy every good moment he had with Kate, even if it was just a laugh over a bad joke.

"I'm sure she misses you," Kate said.

The double meaning behind her words was also abundantly clear - Kate missed him, too. She never said it, not wanting him to know that she missed her old life and her old job. But he knew.

"I'm sure she does, too." Clearing his throat, Castle glanced at his watch. Despite the distance between their two cities, he knew that they were in the same time zone and observed, "Shouldn't you be getting to work soon?"

"I'm on my way now," Kate responded, the amusement in her voice not quite hidden behind the smirk he could imagine graced her lips.

"Don't tell me you've gotten ready for work while you were on the phone with me?" he asked despite having heard the entire process.

"Castle, you of all people should know I'm a woman of many talents."

His eyebrow raised and he nodded involuntarily at her very true words. His mind was already conjuring dirty pictures of her, the kind where memory and fantasy blended everything into a hazy image of lusty beauty. "You are. You definitely are."

"So what are you up to today?" Kate asked.

"Um... writing," he lied.

He hadn't written in the three months since she'd left for D.C. He had plenty of ideas, plenty of inspiration and notes from all their cases together. But when he sat down at his laptop to work on his next Nikki Heat novel, he felt too starved of her company to focus on writing. How could he describe the complex, ongoing relationship between Rook and Rook's muse when his own muse was so far away? How could he delve into Nikki's emotional reactions to her latest case if he wasn't there with Kate? He just couldn't do it.

Quickly changing the subject, he asked, "When do you have another day off? I can fly down whenever, even if it is just for the day..."

He'd already made several trips to the nation's capital that summer, although he often found himself alone in Kate's apartment than spending time with Kate. On the few occasions they actually got to spend time together, she was often tired from long hours spent at the office. But Castle didn't mind. Even watching movies together in her tiny apartment was worth the travel, just to be with her.

"Actually, I was thinking about coming back to New York," Kate said. "This weekend."

"This weekend?" he echoed, forgetting until the last minute to keep the desperate hope out of his voice. She hadn't come back to New York since the job in D.C. began. "This weekend would be good."

His mind was already processing the flight schedules between the two cities. He already had them memorized, already knew how long the flight took and how long the security line at the airport would be. It was Thursday morning and his heartbeat sped up at the thought of seeing her in just a day. Surely she'd fly up on Friday night and stay until Sunday? That would give them two full days together. They could go to the park or maybe the theater. There was a new restaurant he knew she would love and the owner had already promised him a table any time-

"Castle?"

"Sorry," he answered, realizing he had zoned out at the mention of her returning for the weekend. "What were you saying?"

"I was saying that I have tomorrow off, so I thought I'd catch the late flight after work tonight. I can catch a cab from the airport-"

"I'll pick you up," he interrupted.

"It'll be late. Probably close to midnight when my flight gets in."

He pictured her looking hesitant, her eyes cast downward as she caught her bottom lip gently between her teeth. The gesture was such a tease, and yet, he knew she did it unconsciously and not just to torture him.

"I'll be there."

"Then I'll see you tonight."

Her flight was late. She frowned at her watch, angry at the flight attendant who was watching her from two rows over to make sure she didn't turn on her cell phone. Like she could really take down a plane with a cell phone. But the cop in her obeyed the rule despite the fact that the woman in her - the woman who hadn't seen her boyfriend in months - wanted to ignore the flight attendant and all of the FAA's stupid rules and text the man she knew was anxiously waiting for her outside of security.

Mechanical issues had kept her plane on the ground in Washington for an extra hour, leaving her arrival time in New York well after midnight. She resented the precious time wasted, time she could be spending with Castle, wrapped up in his Egyptian cotton sheets or gazing at him across a glass of ridiculously expensive wine. They talked on the phone almost every day, but getting to see him, to touch him... She needed that contact to keep herself sane.

Her investigation was a bust. It was her first case with the task force, her first real case as the lead investigator, and within an hour of looking through the file she'd realized that the so-called electronic bank robberies had to be an inside job. With a little bit of checking, she'd managed to isolate 45 of the 62 unusual transactions to a newer bank employee, one with a boyfriend whose rap sheet included bank fraud.

The case was an easy hit, something she knew she'd been thrown as the newest member of the federal task force. And part of her appreciated getting to demonstrate her skills and stretch her investigative muscles. But another part of her, the part she'd been ignoring for the last several months, just wanted the challenge and thrill of a regular homicide case.

"Welcome to JFK International Airport. The local time is currently 12:47 a.m. You may now resume using electronic devices-"

Kate had already hit the button on her cell phone to power it back on, ignoring the rest of the flight attendant's chipper speech thanking everyone for their patience. But as she turned her phone on, Kate saw that she had no missed calls, no new text messages.

Frowning, she sent a quick text to Castle.

Flight was delayed. Just landed.

His response followed after several long moments.

I'm here. See you soon.

She could see him standing in the terminal, surrounded by the few other families who were so anxious to see their loved ones arrive they'd waited at the airport. She imagined the young husband and child waiting for the female soldier seated in the row behind her. She could see Castle trading jokes with a young business man, the fiancé of the gentleman who'd been seated next to her during the flight - Chris.

Perhaps fueled by the need to see their mates, she and Chris had talked a lot during the flight. He was a scientist and environmental activist who spent much of his time studying endangered species in Brazil. Kate found herself wanting to introduce him to Alexis until he'd mentioned his fiancé, Kevin. The two young men hadn't seen each other in months. As Chris described their separation and the joy he felt at planning their wedding, Kate found herself examining her own relationship more carefully.

She had Castle, wholly and completely. She could marry him so easily, and they could begin their lives together.

But that would mean giving up on the federal task force job, the first part of her career which hadn't been driven by trying to find her mother's killer. The thought of quitting made her feel like a failure.

The terminal was eerily quiet and empty as the passengers from the late plane strolled down towards security. Their leisurely pace seemed out of place in a building usually teaming with activity and people.

The doorway taking them out of the secured area was wide enough to let four men walk abreast, but they were spread out enough to let people through in one's and two's, which just helped to emphasize the poignant homecomings.

Kate's fellow passenger Chris walked a dozen steps ahead of her, his long legs and excitement carrying him quickly into the waiting arms of his fiancé. A few people seemed to notice the two men embrace, but no one said anything. The soldier in uniform picked up her tiny daughter who ran to meet her as she shouted, "Mommy!"

And then there was Castle.

He stood off to the side waiting for her, his expression tired but incredibly pleased to see her.

"Hey, Castle," she said.

He responded simply by kissing her, a slow, sensual, romantic kiss that was just barely appropriate for public view. When he pulled away, it was only a short distance, just far enough to see her but he still held her close to him.

"How was the flight?" he asked.

"Late. Sorry you had to wait so long."

"Not a problem. You know I'll always wait for you."

She nodded, looking away. She knew that his meaning encompassed more than standing around outside security at the airport. "I know."

Kate glanced at the soldier and her daughter as they were quickly joined by a man she supposed was the woman's husband and the girl's father. Kate found herself wondering if that would be her in a few years, greeting her kids at an airport. She knew Agent Shaw did it. She managed to be a mother even though her work with the FBI frequently took her all over the country. It was possible, Kate knew. She just wasn't sure it was what she wanted.

She caught Castle looking at Chris and Kevin, who were huddled together a short distance away speaking in the sweet endearments of a couple too long separated.

"They're planning their wedding," Castle observed, his tone indecipherable.

Kate smiled, but it did not quite reach her eyes as she was reminded of the uncertainty of their own situation and the emptiness of her left hand ring finger.

In that moment, standing between people who represented two possible futures, she made the biggest decision about her future that she'd ever made.

"You ready to go?" Castle asked. She nodded and they made their way through the small crowd.

"Everything looks the same," Kate observed as she stepped into the loft.

"You've only been gone for a few months," Castle pointed out. And neither of them knew how many more months would pass until the next time she returned.

"Still," she said, but nothing more. He took her bag into the bedroom, leaving her to wander through the living room into the kitchen.

"Are you tired?" he asked when he'd returned. She was just standing in the kitchen, staring at the countertops, looking somewhat lost.

An instant later, he realized that Kate looked nervous, not tired. She seemed hesitant, as though she was trying to work up to a subject she would rather avoid. He watched as she pressed her lips together tightly, a tell-tale sign, and then glanced around as if expecting someone.

"My mother's out for the night," he supplied.

"How is she?" Kate asked, seemingly seizing on the opportunity for a distraction.

"She's good," he said simply. Castle knew the question was a way for her to stall; Kate asked about his mother and daughter regularly during their phone conversations and was almost as up-to-date on their lives as he was.

Kate nodded at his response, her apprehension almost palpable. Castle fought against the panic he felt rising up in his chest. Was this it? After so many months apart, trying the long distance relationship thing, was she finally going to break up with him? Is that why she had flown up for the weekend?

Suddenly, Castle wanted a distraction as well - anything to postpone that moment of truth.

"How's your dad?" he asked.

Kate answered almost too quickly, "He's really good. Busy at work."

Castle flinched at those words - "Busy at work" was an all-too familiar phrase for him when it came to Kate. She must have noticed because she looked away again, that nervous expression returning to her face.

"So, are you hungry?" Castle inquired as he took a step towards the kitchen. "I've got leftovers, but I could also whip something up if you feel like anything in particular..."

He paused when he realized she was simply standing and staring at him, her body tense and her expression worried.

"Kate?"

"Castle, we need to talk."

And here it was, the reason for her trip. She had been too busy all summer with the new job to fly back to New York for a full weekend. Each time he'd suggested it, she said that it was just too soon to be taking off so much time. Castle knew she wanted to impress her boss with her dedication, but at the same time, he hated not getting to see her.

He hadn't pressed it, hadn't asked for more than he thought she could give. The situation was so tenuous anyway, he worried that any bit of misplaced pressure would shatter everything.

And here it was falling apart anyway.

Kate knew she was messing this up, this conversation that was so important not to mess up. She had been thinking about it all day, ever since leaving work and taking the cab to the airport in D.C. But she still had no idea how to say what she needed to say. Wishing desperately for Castle's gift with words, Kate pressed on.

"I was hoping we could finish the conversation we had a few months ago," she said. "In the park. On the swings."

When he'd asked her to marry him.

She hadn't told him "no" that day. At the same time, she hadn't quite told him "yes" either. Instead, they had agreed to postpone the question for a while, to let her take the job in D.C. and see how it went. It was too soon to make such a big decision, she'd argued, as they'd been officially dating for less than a year.

Had she been truthful with him, Kate would have admitted that his proposal frightened her. Everything about their relationship had scared her from day one, from the first moment she realized he was the man for her, that he was her one and done.

And to be completely honest, what scared her most was the very real concern that she would screw it up. She'd come close already on several occasions, and the past months of them being apart had only worsened the situation. It was time for Kate to make things right.

"Are you sure?" Castle asked pensively. He'd across the kitchen to stand in front of her, just a few feet away.

He was giving her a way out with his question, the opportunity to push it off a few more months. Kate wondered at that, at his patience. But a moment's reflection as she looked in his eyes answered the question. He didn't want to hear her answer because he believed he was about to be rejected.

"I'm sure."

Taking a deep breath, Kate began to speak. "Castle, when we met, I thought I knew who I was. I had this identity as a cop, and that was my whole life. And I was good at it. Really good. But I didn't ever really think I could do more... I didn't think I could be more, until I met you."

"Kate-" he tried to speak, but she interrupted, needing to get it all out before he said anything.

"You made me believe in myself more than I ever did on my own. You made me see that I can be anything I want to be and that I don't have to let what was done to my mom define me."

She went on, "Castle, I know how hard it has been the last few months. And I really appreciate how much you've done and put up with from me to try and make this work. But I think we can both agree that it isn't working. Phone calls and occasional visits aren't enough for either of us."

As Kate took a breath, she locked eyes with the man in front of her. He made no attempt to speak despite the naked fear she saw in his features.

"That's why when I go back to work on Monday, I'm handing in my resignation."

Castle stared at her, not sure what to say. His mind was having trouble processing the words coming out of her mouth, the expression on her face. None of it made any sense. She was here to break up with him. She had already given him the "you've made me a better person speech" and explained how things weren't working long distance.

But she was quitting her job in Washington?

"You... you what?" he stammered. An instant later, he mentally berated himself for a such an unsophisticated response. "I mean, are you sure?"

She smiled enigmatically at his question, but nodded confirmation. "I'm sure. I'll admit, I was on the fence about it when I got on the plane. I wanted to talk to you and see what you thought. But after seeing those families at the airport, I can't... I want a life with you, Castle. And that isn't going to happen with me in another city."

He stared at her as he tried to process her statements. The change from what he had been expecting to what he was hearing left him a dizzy with the unexpected joy.

Kate must have mistaken his silence as her features turned to hesitation. "That is... if you still want a life together," she said uncertainly.

Castle did not have to think about it. Despite the horrible months of their separation with Kate in D.C. with the feds and him pining for her in New York, he had no doubts. After following her around on her job as a homicide detective and chasing after her personally for so many years, he was not about to let her go, not when it looked like she might finally be ready.

"I do," he said. "Very much."

Before Kate could blink, he had his arms around her. His lips met hers in a slow, thoughtful kiss. He held her with passion and longing instead of the desperation and fear which had driven him to propose that day on the swings.

Pulling away just far enough to see into her eyes, he mustered up his most serious expression and asked, "Kate Beckett, will you marry me?"

He waited to see the slight crinkle of her eyes signaling a genuine smile before adding in a more light-hearted tone, "And for real this time. No more of this 'let's see what happens in Washington' stuff first. I want a real answer."

She knew his caveat was partially serious, but his playful manner kept her grinning as she answered, "Yes. I will marry you."

"Really?" he confirmed, looking positively gleeful at her ascent to his proposal.

"Yes," Kate reassured him, amazed at how easily the answer came to her lips.

She had always known that she wanted to take this step with him, even if she had allowed the job in D.C. serve as a test to their relationship. But she had assumed the answer would be difficult to give, just as it had been so hard to admit her feelings for him. But accepting his proposal had turned out to be surprisingly easy.

"For real-really?" he said, still questioning.

Apparently getting him to accept her answer was going to be the hard part.

"Yes, Castle, for real-really. Yes. I want to marry you. Now and always."

She would never know what he was about to say in response because she interrupted him with another kiss, the kind that left his knees wobbly and completely stole his attention.

The twenty feet to his bedroom was littered with clothing as they made their way in a languid, unhurried fashion. Neither of them spoke, instead using their mouths in more pleasant endeavors as they celebrated Kate's homecoming.

Some time later, when their passions had been satisfied and their brand new engagement celebrated, Castle slipped out of bed to pad into his office. Kate quickly understood when he returned with a little black velvet box.

Inside the box was the ring he'd offered her that day on the swings. Her ring.

"May I?" he asked as he removed it.

She blinked away tears as she answered, "Please."

The ring fit her finger perfectly, as though he had secretly taken her measurement when she wasn't looking. Kate had not examined it too closely when he'd first proposed, partially because she had not given him a firm "yes," but also because she had worried about falling in love with it too soon. As she stared at the shiny metal and sparkling diamond in the low light of their bedroom, Kate allowed herself to be dazzled.

The stone was excellent quality, although not so large that she would feel uncomfortable with its grandness. The band was simple but classic, very much like her mother's ring.

"I love it," she said.

"I love you," he responded.

"I love you, too."

It was only the second time she'd said the words to him, but this time, they came easier. Everything seemed easier with this weight off of her chest.

After a few minutes of silence, Castle asked, "Are you going to try and get your old job back?"

"Gates said she'd reinstate me if I wanted to come back. She also said I'd be a fool to give up such a good opportunity, working for the task force."

Castle shrugged. "What does she know?"

"Honestly, I don't really regret quitting. The crimes we were investigating were federal, but they weren't as interesting and exciting as working in homicide. Even my bank robbery case... There was a lot of money involved and a pretty sophisticated operation, but..."

"The victims aren't the same," he suggested.

"Yeah, and the investigations aren't as... personal." She paused for a moment before adding, "There's no story."

Castle nodded in understanding.

Kate bit her lip before continuing, "I'm sorry it took so long for me to realize that."

Pulling her against him so that her body was firmly spooned against him, Castle answered, "I'm just glad you're here now."

"Me too."

A few seconds passed before Castle began in a cheerful, excited voice, "So... wedding plans! Now these are just a couple of thoughts, but what do you think about having the entire ceremony in hot air balloons? We can be in one and then have everyone else in other balloons that are close by."

"Castle..."

"Sound might be a problem. I guess we can use a microphone and pipe it wirelessly into speakers in all the other balloons-"

"Castle," she interrupted him again.

"Huh?"

"No balloons."

"But-"

Kate reached around to place her hand firmly over his mouth, cutting him off. "Castle, we have plenty of time to plan our wedding. And I'm sure we'll both be making compromises. But let me make this clear from the very beginning, okay?" She felt him nod. "No balloons."

With a shrug, Castle agreed to her restriction and Kate dropped her hand. The warmth of the bed and her fiancé were inviting after such a long day, not to mention their emotional conversation and... the invigorating aftermath. Kate felt her eyes begin to droop shut as the promise of a new day began to lull her to sleep.

"What about a steampunk wedding?" Castle suggested enthusiastically, obviously not tired in the least.

"Castle."

"Hmm?"

"Go to sleep."