Set mid season four, slightly AU, if Castle had asked Beckett out earlier, she'd said yes, and they'd started dating.

Disclaimer: I don't own Castle or the characters.

Castle hadn't meant to say it but he had and neither of them knew how to handle it.

"I can't do this anymore, we're over."

He'd regretted the words as soon as they'd left his mouth, had wanted to take them back, but pride and the anger he felt stopped him.

"If that's what you want then fine, we're over," she said in reply and then she turned and left his loft, slamming the door behind her and walking away from the one relationship she's ever been in that she thought had the possibility to last.

XXX

Beckett half expects him not to show up at the precinct the next morning so she's surprised when a cup of coffee is placed in front of her and she looks up to see his unsmiling face staring down at her.

He doesn't say anything as he takes a seat, and neither does she, so they both just sit there drinking their coffee and desperately hoping for a case to distract them.

There are sideways glances between them both and whenever they catch the other looking they look away and they still never speak to each other. Castle draws on the notepad in front of him and Beckett does paperwork and they don't say a word.

Their relief comes a few hours later when they get a call saying a body has dropped and so they're distracted for the rest of the day.

Come home time though, things are different. Work had managed to distract them all day but now it's just the two of them left and neither of them knows what to say.

Beckett wants to apologise for the words she'd said to lead Castle to ending their relationship but she doesn't know where to begin, doesn't know what he wants now so she just keeps her mouth shut and lets Castle walk away from her.

XXX

It goes on like that for several weeks, only speaking when they have to, when its case related, but each day he turns up is a relief and all she can think is at least she hasn't lost him for good. That had been one of Beckett's fears of finally diving into a relationship with him, that she'd only screw up and lose him completely. She'd gotten scared and she'd taken the easy way out, hurting them both in the process.

She wanted to do something to fix it but she doesn't know how to. She wants him, she loves him, but after their fight, the things they both said, she's not sure if she could be good enough for him or if he even wants her any more.

She misses him, the partner she had, the best friend and she regrets what she's done.

They'd gotten into an argument and she'd ended up saying that she'd regretted ever starting a relationship with him in the first place but that was untrue. No, what she regretted now was saying that to him, pushing him away and hurting him when that was that last thing she ever wanted to do. She wanted to hold him close, to be the one that comforts him when he's hurt, not be the cause of it and she's terrified if she apologies to him, that she'd only end up hurting him again and she doesn't want that at all.

But maybe she can talk to him, apologise and they can go back to just being friends, maybe that'd be what's best for everyone involved. He'd said they were over but he's sticking around the precinct so the best thing she can do would be to apologise to him, see if they can still be friends, so they can both move on with their lives.

XXX

"Can we go someplace and talk?" Beckett asked him a week later, having finally gathered the courage she'd need for the coming conversation.

He scoffs, bitterness seeping into his voice, "now you want to talk?" She hadn't properly spoken to him in a month, after he'd broken up with her. And he can't blame her, but he can't help wondering what's changed now. He's stuck around the precinct to be close to her, which is probably selfish, but he still wants to be near her, still wants to be her partner.

"Please, I have something I want to talk to you about."

"Fine, let's go."

He took her back to her place, where he said his mother and daughter would be out, and it's fitting that what she's about to say should happen here after this being the scene of the fight that broke them.

"So, what do you want to talk about?" he asked as soon as he'd closed the door. He didn't want to wait, he wanted to have whatever conversation she wanted to so he could go back to pretending that everything was fine between them and that she hadn't broken his heart.

"I just wanted to say how very sorry I am for everything I said and I hope we can still be friends after what happened." Her voice didn't waver as she spoke but the confidence was fake, her hands were shaking and her heart was pounding in her chest.

"You want to make sure we're still friends?" he asked incredulously, this isn't exactly the conversation he'd been anticipating.

"Yeah," she replied, hanging her head. It is what she wants, to stay friends with him but she also wants so much more. It's not fair of her to ask that though, not after she's hurt him so much which she's sure she'll continue to do in the future. He deserves all the happiness in the world and it hurts her that she can't be the one to give that to him. And she can't forget that he's the one that broke up with her.

She watched as his face crumpled in front of her, "You said you regretted ever agreeing to go out with me in the first place." He wanted to talk about what had happened, wanted to clear the air between them and if there's even the smallest chance that talking about it could fix what happened, then he's going to try.

Beckett sucked in a breath, a fresh wave of pain thundering through her chest as she remembered her words to him, one's she'd said out of anger, one's she hadn't meant. And then he'd told her they were over and her heart had cracked but she'd accepted it, had always known it was coming eventually because she'd screw them up somehow so she hadn't put up a fight, she'd just left.

"I'm sorry about that, I didn't mean it-"

His words interrupted her, "then why did you say it!"

She could see he was angry now, anger he must've been hiding since their fight.

"I don't know, I was angry," she replied, "and I knew it was a bad idea for us to start dating in the first place."

"Then why did you even agree to go out with me?" he asked, hurt now clouding his voice as he thought about all the time they'd spent together in the short two months they'd been dating. How happy he had felt during the small amount of time he got to be with her and he'd thought she'd felt the same as him but maybe he'd been wrong.

"Because I was in love with you!" she answered, practically yelling now and that is not how she thought her first time telling him that would be.

"What?" he asked, dumbfounded by her words, actually taking a step away from her in shock.

"And I was too selfish to turn you down when you asked me out even though I knew in the end I'd only hurt you and it would ruin us but I love you so I said yes anyway and that's why I hope we can still be friends, that I haven't ruined that too."

Castle stared in shock as she spoke, trying to process her words.

"You love me?" he finally asked, he thought she didn't have feelings for him, was why she didn't want to date him anymore and why she regretted originally agreeing to go out with him but apparently it was the exact opposite. He'd only broken up with her because he thought his feelings weren't reciprocated, if only he'd known and this whole mess could've been avoided, he wouldn't have stepped back so easily, he would've fought for her.

She nodded in reply, she'd said it so she couldn't deny it anymore and at least he'd know, that now, whatever happen, she wouldn't look back and wonder that things may have turned out differently if she hadn't told him how she feels.

"I don't want to just be friends, Kate," he said, taking a step towards her and breaching the gap that was between them, raising his hand slowly to settle on her cheek, "and I should've never said that we're over, I'm so sorry that I did, because I'm in love with you too."

It was her turn to stare at him in shock, apparently they'd both been hiding their feelings pretty well from the other. Beckett almost wanted to laugh, thinking about how all of this could've been avoided if they'd just been more open with each other in the first place.

Beckett didn't speak but she tilted her head into Castle's hand, relishing the feel of his warm skin pressed against her cheek.

"What happens now?" Castle asked, the fight still fresh in his mind. He may know that Beckett loves him but did she still want to just remain friends?

She surged forward then, closing the remaining gap between them and kissed him, hoping to answer his question with her mouth.

"Does that mean we have a second chance together?" Castle asked, the hope clear in his voice at the thought that they hadn't ruined things between them entirely.

"Yes," Beckett answered immediately, nodding as her hands cupped his face," if that's what you want."

He kissed her again, showing rather than telling her what his answer was.

"Did you know I bought you a ring?" Castle said as he pulled back, wanting to be completely honest with her about where he saw this relationship heading, wanting there to be no more misunderstandings in the future.

"What?" she asked, her voice louder than she'd meant it to be as her eyebrows shot up.

"After our first date, the next day I went out and bought you a ring, that's why I was late to the precinct that morning.

"Because you bought me a ring?" She still couldn't believe it, he was really that sure of her after only one date? And of course, she had to go and screw that up and break both their hearts in the process.

"Why are you telling me this now?" she asked. Just earlier today she saw no future for them and now she's now sure what she sees but they've been given another chance together and now he's telling her that he wants to, or at least wanted to, marry her one day.

"Because I want to show you how sure I am about us, how much I want us to work and how much I love you. And I shouldn't have walked away like I did, but after what you said I got scared, I thought you didn't feel the same about me as I did about you so I let you go, a mistake I won't be making again. And one day I will propose and I hope that you'll say yes."

She was kissing him again before he knew what was happening and he kissed her back, trying to pour all his love for her into the kiss.

Beckett pulled back to rest her forehead against his as she spoke, "I'm not going to run anymore, I'm done running and I'm in this, for good."

"Me too," he grinned back and then he kissed her again.

Thoughts?