A/N: Because there just aren't enough Probable Cause fics floating around out there. Thanks again to Sonicaskettshipper for the idea. Takes place at some point during the episode after Castle has made bail. Heavy spoilers for sneak peeks, interviews and tweets for that episode.
I know this is pretty gratuitous but it's a conversation I think they need to have.

Upload Date: October 28, 2012

Chapter Rating: T

Chapter Summary: After the Tessa Horton case forces Beckett to deal with her trust issues towards Castle she comes to a decision, and goes to Castle's loft after he is released on bail to confront him with her choice.

#32

She listens to Lanie. She goes with her gut. The way he looks at her when he opens the door isn't quite as cold as the last time she came here to apologise, but it's wary, observant.

"What is it? Are you here to arrest me for another murder?"

"Castle."

He sighs. "I'm sorry, I shouldn't make it worse."

"It's ok. I'm not here as a cop, Castle."

He responds slowly. "Then, what are you here as?"

"Your girlfriend."

"Are you still my girlfriend?"

"I hope so. Do you still want me as your girlfriend?"

"Kate, of course I do, but it's not that simple."

"I know." She sighs. "Can I come in?"

He pauses, and then steps aside. "Of course."

He shuts the door. She turns back to face him.

"Castle, even before I met you, you had this reputation as a womaniser. Even after I got to know you and I realised there was more to you; that you did respect woman and that you could have something real with someone... you would say something or do something – and I know most of the time you were just joking but I also felt that it came from a real place – that would convince me that you're just not the kind of guy who can be with just one person. This isn't about you having a past. I've been with other guys, too.
"But it seemed like, with the exception of Kyra, they were all... subordinates. I wanted so badly to give you the benefit of the doubt, but every time I did, something would happen; you'd run off with your ex-wife or make out with an ex-jewel thief or join the mile high-club with a blonde flight attendant or I'd walk in to see you being straddled by a bikini-clad reporter.
"The night I was suspended, the night I came here; that was the night I decided none of that mattered. I decided to let go of every excuse I ever had not to be with you and just be with you. That night, everything was just so clear. I haven't had that clarity for a while and the only reason that we're still together is that when it's just us, it's so god-damn amazing that I don't want to let it go. I'm clinging on for dear life, here, Castle. Now that we've crossed that line, I can't imagine going back.
"When other people get involved, that's when we tend to have problems – and that's an issue because we can't stop other people coming along and complicating our lives. This whole thing – it wasn't even really about Tessa. I knew you weren't with her. I knew it must be part of the set-up."

"So, you believe I'm being set-up?"

"How else do you explain all of this? It's the only thing that makes sense. But anyway, we'll get to that later. This whole thing just brought up some issues I've had for a while now, that I've ignored, and I really shouldn't ignore them.
"I should talk to you about it. We've talked about it a little, but there's some stuff that needs to be said, things I need to know. Castle – don't freak out when I say this – marriage is a big deal to me. It's sacred. And you did it twice. And I've wondered what went wrong, and I've speculated, but I need to hear it from you. I need to know."

Castle sighs and runs a hand through his hair. "Well, with Meredith, it was just a mistake to get married. We were way too young and Meredith – God love her – is not the marrying kind. It was just this spontaneous weekend in Vegas that lead to this spontaneous honeymoon that led to this child neither of us was ready for. Luckily, that part worked out for me but Meredith just couldn't commit to the responsibilities – even when she was here. I mean, she was working so much and I think when she actually made an effort to be a wife and mother, she felt trapped and so she handled that by sleeping with her producer."

Beckett's eyes widen. "Castle..."

"It's ok, it was a long time ago. At the time, I was mad – but mostly hurt. I still wanted to make things work, though. I still wanted to be a family. But she wouldn't take my calls. She just took off to Malibu and he next communication I had from her was the divorce papers she served me with.
"With Gina, there was more thought that went into it. It was a much more mature relationship. There was a friendship there, a mutual understanding and respect that I didn't have with Meredith. But we didn't know how to balance work and home life.
"There was fighting, fighting that we didn't know how to resolve. Plus I... didn't mean to, but I think I kind of shut her out of my relationship with Alexis. I think I was trying to keep my identity as a husband separate from my identity as a father – which is ludicrous, I know, considering we were all living under the same roof. I think we could have dealt with those issues if we'd really tried, if we went to counselling.
"The one thing that couldn't be fixed, though, what I think was our biggest downfall, was that with Gina, I wasn't with her because I absolutely needed to be. I was with her because it made sense, because I loved her, because we got a long, I found her attractive – but there was no pull, no gravity, no chemical reaction, no... magic.
"After my history, I've gotta be honest, I don't know if I wanna be married again. I do know I want to spend the rest of my life with you; but I love what we have and I don't wanna screw it up by trapping us in an antiquated institution.
"But none of it matters if you don't trust me."

Beckett sighs and takes him by the hand. "I do trust you, Castle."

He looks unconvinced.

She sighs again and pulls him towards her. He takes her into his arms tentatively.

"It's me I didn't trust. I didn't trust my heart. I didn't trust my judgement. I didn't trust that I could feel this wonderful and have it not fall apart.
"I mean, you were right. Demming, Josh – those relationships were easy because they were safe. There was little risk of getting hurt because as much as I cared about them... well it was like you said. It wasn't like gravity. It wasn't what we have.
"If this ended – Castle, it would crush me. It would destroy me. And it would ruin our partnership and I can't lose that. So, I need to know that it's just me for you, that this means as much to you as it does to me. Because I admit, I've been doubting it." She releases herself and looks up solemnly at him. "I only need to hear you say it once, Castle, and I'll never doubt you again, I promise. I just need to hear you say it."

Castle doesn't look away. He stares back, with such determination and certainty in his eyes. "Kate, I only want you. I'm only going to be with you, just you, for as long as you'll have me."

She sighs again, and it's as if a huge weight has been lifted off her chest, because she knows he means it, knows he will keep his promise.

"Thank you," she says, hugging him again.

"Always," he whispers back.

"I'm so sorry," she whispers. "I'm so sorry for doubting you. I know how you feel about me, and if you love me half as much as I love you, I know there's no way you could bring yourself to be with someone else when you're with me, because that's how I feel about you."

He stiffens, and finally, pulls out of the hug to look down at her.

"You love me?"

She smiles. "Yeah," she nods, taking his hand again. "I do."

"Will you still love me when I'm living behind bars?"

"I won't let that happen, Castle. I wast thinking about it on the way here, and I think I might know who's setting you up."

"Who?"

"Well, I figured there's no way this is his first killing."

"well, that's obvious."

"We've already got him profiled as a serial killer, and he's smart. Really smart. The detail that went into this whole set up – it's brilliant. And we know it has to be someone with motive, someone who would want to see you suffer, someone with a score to settle. But what really got to me was his MO; the way he kills."

"Strangling.' He pauses. "You think it's 3xk."

"Is there anyone else you can think of who might have a grudge against you who could pull this off?"

"Well, I really can't answer that. I didn't think Damien was capable of murder, so, I really can't speak for what anyone I've ever met is capable of – except maybe Alexis. I'm pretty confident she didn't do this. Not that she couldn't pull it off, I just know she wouldn't. And I have so many crazy fans – one of whom was convincingly framed as a serial killer and one who actually was a serial killer. But I came to the same conclusion as you," he said gravely. "What happened to Tessa, that was him. Tyson."

His voice breaks on the last syllable, and she thinks she knows what's wrong.

"Castle, it's not your fault."

"I know. Rationally, I know that. But I can't help how I feel, Kate."

She strokes his face with her thumb. "I know, Castle," she says softly.

"So, what do we do now?"

She brings her hand back down. "We do what we do best. We solve the murder. We know who we think it is, but we need evidence. And when we have that evidence, we bring it to Gates and we clear your name. And once your name has been cleared, I take you back to my place and have my wicked way with you."