Title: On What We Agree

Disclaimer: Oh, come on, if this happened in the show I think we'd all die.

Summary: Esposito needs a little help with words. Castle is more than happy to oblige. Kate, however, has no idea what she's agreed to. And she agrees to far more than she planned.

Author's Note: This is just a plot bunny that came to be as I was lazing in bed this morning, and once I'd started writing it, well, it was just too much fun to stop. This is set somewhere in Season Four. No spoilers, but Josh is gone. It's a bit AU, but hey, this is fanfiction.

I hope you like it. Lemme know, I really had fun with this one.

Emma


"Yo, Beckett."

"What's up, Esposito?" she asked, turning to find her three boys crowded around her desk. "Why do I feel like you three need something?"

Ryan grinned. "Well, Esposito here has an important question to ask Lanie."

"You're going to ask her?" Kate exclaimed happily. "She'll be so happy."

Esposito gave her a wary smile. "Thanks."

"So, what do you need with me?" she asked, looking at them. She had a sinking feeling about this.

"Well, Esposito's a bit unsure of what to say, having never done this and all. And while I did get my girl, we both thought maybe this needed a more…experienced touch," Ryan explained.

"Why do I feel like I'm about to be roped into something uncomfortable?"

They all laughed. "No, nothing uncomfortable. Just a little pretend. Why, Beckett, are you afraid of a little role play?" Castle asked.

She narrowed her eyes. "Bring it, Writer Boy."

He grinned and sidled around her, reaching to turn her chair so that she faced him standing in front of her. "Esposito asked if I could give him an idea of how to sweep a lady off her feet. Care to be swept, Detective?"

"By all means, Castle, please, sweep me off my feet."

He nodded and then knelt before her, placing both hands on her knees, leaving the ring box sitting on the desk. He looked into her eyes for a moment and then took a deep breath.

"Katherine," he shook his head. "Kate. We've worked together for nearly four years."

"Four long years," she interjected with a smile.

He laughed. "Categorize them how you will my dear, but suffice it to say, they've happened. And they've been the most amazing four long years of my life. You've shown me that there are real people in the world, made of more than money and smiles. You've let me follow you around, annoy you endlessly, pull your pigtails," he squeezed her knee and she gave a small laugh. "Solving cases with you, doing research—I've never had more fun or felt more worthwhile."

"We do like having you here," she said, laying a hand on his and giving it a squeeze. "But don't take that to heart."

He grinned. "And you keep me so grounded." They laughed. She could hear some of the surrounding spectators laughing too. Were they still there?

"I can't imagine a better place to be, or a better woman to be with. God, Kate, every day with you is, pardon me, but magical, wonderful, spectacular. Yours is the only face I want to see when I wake up and when I go to sleep. I want to wake up with you every day, make you breakfast, bicker over who should drive to the Station, and secretly not care when you win every time." God, his eyes were mesmerizing.

"I want to spend summers with you at the beach and winters here at the Precinct, knee deep in evidence, searching until we fall asleep on the break room couch together. I want to be here with you when we solve your mother's murder, because we will, together. I want to be there to watch you get that justice, and then I want to be there that night when all we do is hold each other. I want to be the shoulder for you to cry on, laugh at, smack, whack, kiss, hug—I want to be your everything and always."

Was that a tear? Was she crying? He reached up and brushed a tear from her cheek, twisting his finger around a curl as his hand fell, tugging gently.

"I want to make you smile when you cry. I want to make you laugh at night, laugh so hard that the murder and the crime and the blood fall away." She felt herself smile. "I want to lay with you, watching old movies, my hand on your stomach, swollen with our child. I want to be afraid of your mood swings and the recipient of your hormones. I want to sit behind you, telling you how proud I am while you scream that you'll never let me touch you again.

"I want to hold our baby with you, pressing kisses to your cheek while I try not to cry because I'm so damn happy." She was crying now. But she couldn't reach up, because she was holding onto his hands so tightly. When had that happened?

"I want to grow old with you, Katherine Beckett. I want to watch our children graduate, spend hours lamenting how I'm not old enough to walk Alexis down the aisle, how I'm not old enough to be a grandpa. I want to pull you close every night and tell you how much I love you, because I'll never stop. I want to be your 'one and done,' your always."

He scooted away from her, releasing her hands. He reached up and opened the ring box, bringing it up for her to see and stared into her eyes. "So will you, Katherine Beckett, be my 'one and done,' my always?"

"Yes."

They stared at each other. What had she said? He was lifting her hand. Why was he lifting her hand? Oh my, he was slipping the ring onto her finger. And now his face was right in front of hers, and there were still tears on her cheeks, but they were both smiling like crazy. Then his lips were on hers, soft and gentle, his hands cradling her face. She brought hers up to press against his on her cheeks, the diamond sitting heavily on her finger.

God, he was going to marry her.

Someone coughed. Rick slowly broke away from her and together they looked over at Esposito. Oh, God, had the whole Precinct really been watching that? Hell, had she just said she would marry Richard Castle?

"Uh, I'm…um, I'm gonna need that back," Esposito said, pointing to the ring on Kate's finger. "But, uh, wow, Castle, that was…that was some proposal."

Kate blinked. Castle blinked. Well crap.

Slowly, they disengaged. Castle shuffled back a bit and Kate extended her hand for him. He gently slid the ring from her finger, his eyes never leaving hers. She couldn't even figure out what she was feeling, let alone decipher the messages he sent her with those captivating blue eyes. What was that feeling in the pit of her stomach? Was it regret, sadness? Was she upset—upset that she wasn't actually marrying Richard Castle, a man she hadn't so much as kissed for the better part of a year?

The ring slipped from her finger and he quietly laid it back in the little black box, closed the lid, and handed it to Esposito over the desk. The Detective took it, looking down at the box with some concern.

"Do you think I can still use this? It hasn't been…claimed or something, right?" he asked Ryan as they walked away without another word to the two of them.

"Dude, I don't know," they heard.

Kate looked back at Castle. He was still on his knees, his hands now suspended on the desk and one of her knees.

"So," he said quietly.

"Hell of a proposal," slipped out before she could stop it.

He grinned. "Yeah?"

"Yeah, might sweep a girl off her feet," she continued. Shut up.

"Oh really?"

She shrugged. "You have a way with words, Castle."

He just smiled. "Good to know they work on you too, Detective."

She narrowed her eyes. He squeezed the hand she didn't realize he was still holding and then stood. She watched as he moved back to 'his' chair and sat down. She turned in her chair so that she was facing her desk, instead of the space where he'd…good lord, he'd proposed, and she'd said yes. In the middle of the Precinct.

She shook her head lightly and busied herself with the paperwork she'd been completing when the entire thing had started. It had seemed so innocent.

"I would, you know," he said some minutes later.

"Would what?" she asked, not looking up.

"Marry you."

Hell. She turned to meet his eyes. "Oh?"

"You'd be a stunning bride."

She blushed. She blushed. Crap. "Oh, well, thanks?"

His hand moved slowly until it met her left, twining their fingers together. "Spring, maybe summer? On the beach, at the Hamptons house, I think. Yes."

"What?"

"For the wedding," he said, like it was obvious. "A small ceremony, just you, me, your dad, my mother, Alexis, and our friends. No press, no muss, no fuss. Just you in the most amazing dress, and me, feeling inadequate and amazed that you're mine."

His finger stroked over her now bare ring finger. "And you'd be so radiant, and smiling, and I don't think I'd even hear what the damn minister was saying because I'd be so wrapped up in you. And then he'd pronounce us man and wife, and I'd kiss you, kiss you until your toes curled, or my mother made a comment."

She laughed. "Would you now?"

He grinned. "Oh yes. And then we'd have the reception right there at the house, with a band and a dance floor set out on the sand. And I'd pull you close and tell you just how beautiful you were as we shared our first dance. And when we cut the cake, you'd smash it into my face and then run away while I chased you until we crashed into Esposito and Ryan, who'd be laughing so hard that they were nearly falling down."

She laughed. He certainly painted a picture. A beautiful, captivating, amazing, wonderful picture.

"And slowly, everyone would leave. You'd have to stop me from following Alexis and the boy she brought out to their car when they left. I figure you'd distract me, somehow."

"Somehow."

He leered. "Oh yes, because once everyone was gone, it would be just you and me, and my dear, we wouldn't sleep."

"At all?" she asked, placing her cheek in her right hand in mock concern.

His eyes darkened. "Oh, there would be a bed, and perhaps a bath, and maybe a hot tub, or the ocean involved that night, but we wouldn't be sleeping in any of them. But," he glanced around, reminding them both of their surroundings. "That's a story for a different location."

She blinked. Hell, they were still in the Precinct. God damn him!

"So, Kate," he said quietly.

"Yes?"

"Would you like to go get dinner with me? I feel like you've used that paperwork as a distraction for long enough."

His fingers were warm on top of hers and his smile was charming and she…the proposal, the wedding…did she? Could she? God, she did. "Sure, Castle. Sounds like fun."

He grinned and stood, extending a hand for her. She stood and slipped into her jacket before placing her right hand in his. She slipped her left into her pocket, so he couldn't see her tracing the place on her finger where the ring had sat. They walked to the elevator together, ignoring the snickering from across the bullpen.

"If you'd like, we could go find you another one," he said once the doors closed.

"Another what?" she asked, turning her head to look at him.

"Another ring."

"Excuse me?"

He grinned as the doors opened and then tugged her out onto the street. Then he pulled her to the wall so that they were out of the traffic of the sidewalk.

"Well, I proposed, and you said yes."

Kate blinked. "Right, but that was…Esposito…"

Castle shook his head, amused. "That was pretend. You weren't supposed to answer."

She scowled. "Damnit, Castle. I didn't think you'd use it against me."

His smile turned from amused to adoring. "No, I'm not trying to use it against you. I'm serious."

"What? You're serious? You want to go buy me a ring? We're not even dating!"

He nodded. "Why not?"

"Why not?" she breathed. So many, many reasons. "Because, God, Castle, what the hell are you doing? We haven't even…We're not…Rick, what the hell are you doing?" she let slip as his hands moved from their sides to her back, pulling her to his chest.

His face was right in front of hers, his breath hot against her lips. "I'm doing what we've both wanted for God knows how long. I want that, Kate, all of it, everything I said. Do you want me to tell you again? I will, you know."

Kate found herself succumbing to the feelings they pretended didn't exist. It was powerful, like a tidal wave or a tsunami, crashing over her. He was serious. He wanted all of it. He wanted to marry her, and have 'little Castle babies' with her, and hold her close at night and kiss her awake in the morning…

"Okay," she breathed. It surprised her as much as it surprised him.

"Okay?"

She nodded against his forehead. "Take me to dinner, Mr. Castle, and convince me to let you court me."

His eyes glinted and he leaned down to capture her lips with his. This kiss was passionate, full of fire and desire and suppressed need. When they finally broke apart, Kate was panting and Castle, Rick, wasn't doing much better.

"Come on," he said softly, peeling them apart to take her hand again.

"Where are we going?" she asked as he hailed a cab.

"My place," he said. "I'm going to cook you the most amazing meal of your life, and then, my dear, I'm going to convince you to spend the rest of your life with me."

"You think food is your best strategy?" she challenged, using the words to fight the surge of butterflies in her stomach.

He grinned wolfishly at her. "Oh, I have many tools in my arsenal, Kate Beckett, and you can bet that I'll use them all before we die, old and gray together. But, tonight, I need to convince you to let me court you. Tomorrow, I can convince you to move in."

She laughed and let him usher her into the car. Life with Richard Castle would be nothing if not interesting. And, as he took her hand and pulled her into his side, his fingers sliding over her ring finger again, she couldn't help but wonder just how long it would be before he was back on one knee and they were standing at that alter on the beach. She was surprised to find that she hoped it was soon. Because, after all, she'd already said yes.