A/N: so I'm going to write these chapters as sort of flashbacks as a continuation of 'I Never Could Forget Those Cheekbones'. (Flashbacks are in italics.) The epilogue to that story referenced certain episodes, so I'm kind of going back through those.

If you haven't read it, Castle and Beckett got together at the beginning of season one, engaged after Demming was around and married just before Roy was killed/Kate shot. Set present day (ie. mid to end season 6 (and probably into hiatus) won't be spoilers for season 6 until I get to those episodes in about 30 chapters time!)

1x10 - A Death In The Family

"Hey, Castle?" Beckett whispers into the darkness towards the sleeping lump of her husband beside her.

"Mmhm..?" he replies sleepily.

"Thank you." She says.

Castle turns towards her, so they're both led facing each other. "For what?" he asks.

"For uhm, for sticking your nose into my private life." She lets out a deep sigh. "If it wasn't for you, I would never have caught my mother's killer and I know we still don't have the person behind it but it's enough for now. So thank you."

Castle leans forward to press a kiss onto Kate's forehead. "Always." He whispers.

"Castle, you touch my mothers case, and you and I are done." Beckett said.

"Okay. Why don't you want to investigate it?" Castle pressed.

"Same reason a recovering alcoholic doesn't drink. You think I haven't been down there? You don't think I haven't memorised every line in that file? My first three years on the force, every off-duty moment was spent looking for something someone missed. It took me a year of therapy to realise if I didn't let go, it was going to destroy me. And so I let it go." She stepped into the lift, Castle still behind her.

"Sorry, I didn't know."

"Yeah, well now you do." And Castle knew that the elevator doors closing in front of them was closing the conversation too, she wasn't opening up anymore. During the past few months, he'd learnt quite a lot about Kate Beckett and she'd told him about her mother and what she was like. He hadn't said anything yet, but he knew he loved her, knew she was the one for him. He just had to find the time to tell her when he was as sure as he could be that she wouldn't run.

"You know, I'm still not happy you went back to Sorenson for help on that case." Castle mutters. "And you gave him a doughnut."

Looking up at him, Kate can see him pouting like a child who hadn't got their own way. "Yeah well, I'm giving you a child. I think that outranks a doughnut, eh?" She says, giving him a quick kiss.

"Yeah, I guess so." Castle says in defeat. Though obviously, a child with the woman of his dreams is a hell of a lot better than a doughnut.

"Anyway, he helped us with that case."

"I love it when you say things like that." Castle smiles.

"You..like it when I bring up ex-boyfriends?"

This time it was Castle's turn to roll his eyes. "No, when you say things like 'us' and 'we' and 'our case'. Honestly that first case I helped you on I never thought I'd live to see the day you said things like that."

Beckett smiles at him. He really was adorable. "Yeah, and just as I was telling the Captain how I couldn't have done that case without you, you were doing the one thing I had categorically asked you not to do."

"It took me over an hour to pluck up the courage to even tell you, you know. I selfishly put myself first and didn't know if I could cope without you..you'd said we'd be done and I didn't know if I could deal with that. But Murray said you had to know and he was right. I did wonder if you were ever going to speak to me again though.."

"Castle, what's going on?"

"It's about your mother."

"What do you mean, it's about my mother?" Beckett growled in the hallway of the hospital. "Castle, what have you done?"

"I..uh, look. Before I you bite my head of and never speak to me again-"

"Castle, I'm asking you one last time - what. Have. You. Done?"

"Can we take this somewhere a little more private?" He asked. Other people in the hospital corridor were starting to stare. He didn't need this ending up on page 6 if someone recognised him.

Shooting him one more ferocious look Beckett stood up and walked down the hallway and into the empty relatives room. Closing the behind them, she spun around to face him. "So?"

Taking a seat and grateful that she did the same - she was scarier when she was stood in those heels - Castle began to explain what he'd found out. How he'd met with the top forensic pathologist in the city and had him analyse the evidence photos and got his opinion. "So, it turns out your mothers murder wasn't random gang violence."

Beckett looked close to tears. She hated him with a passion right now for bringing this up and poking his nose in where she had specifically asked him not too, but she had to know exactly what he knew, she couldn't walk away just yet. "Oh god..what are you saying?" She whispered.

"What I'm saying is that from the evidence Murray saw, your mothers murder was pre-meditated. It was a professional hit and not an accident." He finished, anticipating her reaction with bated breath.

Beckett was silent for a moment, taking all of this new information in. "How could you do this, Castle?" She said quietly. For some reason, he'd rather she was shouting at him. This quiet voice she had was much worse. "You know how hard it was for me to get out of that rabbit hole and what are you trying to do, push me back down?"

"No, Kate, I-" he started, but Kate interrupted him.

"Don't bother. Save your breath Castle, I'm not interested. Do you not think I looked into every single possibility when I went over the case files myself? And what do you think this has achieved anyway? So we know it was a professional hit but that doesn't bring us any closer to finding out who did it. If anything, it's harder - we might someday get the guy who actually killed her but we might never know who ordered it." She let out a deep breath before I continuing. "And I'm standing by what I said - we're done." And with that, she walked out of the relatives room and out of the hospital. Castle just hoped it wasn't out of his life for good.

"That week you didn't speak to me was horrific, you know." Castle murmurs into her hair. They were cuddled together in bed, Beckett's head against Castle's chest. "I honestly thought I'd lost you for good."

"Yeah, well you might have done if I hadn't realised I couldn't live without you." Beckett says. "I was angry, so angry but you did it for the right reasons..it just took me a while to see that."

After leaving the hospital, Kate went to the only person she felt she could trust right now - Lanie. She didn't call first and just hoped Lanie was home. Knocking on the door to her apartment, she was relieved when Kanie answered.

"Kate! Hi! What're you doing-" Lanie stopped, looking at the expression on Kate's face. "Wait, what's wrong?" She asked, opening the door to let her into the apartment.

"He did it. He went there even though I asked him not to." She whispered, sinking onto the couch."

"Who? Did what?" Lanie asked, feeling slightly confused.

"Castle. He investigated my mothers murder."

"That son of a bitch!" Lanie exclaimed. "How could he do this? He knew how hard it was for you to let it go, why would he bring it back up?" Lanie was angry. Castle hadn't seen what Beckett was like back then and she desperately didn't want her friend heading back in that direction.

"He..he said he found something." Beckett said.

"Found what?" Lanie scoffed. She'd been over the case files herself, she couldn't see that anything had been missed in the original investigation.

"It wasn't gang violence, Lanie. It was a hired hit." She said, looking up at her friend with tears in her eyes. "He got some top notch pathologist to look at it, he said the stab wounds were too clean and practiced for it to be anything but."

"Oh god Kate. I'm so sorry." Lanie soothed, sitting next to Kate on the couch and wrapping her arms around her. "God that's just awful. What had she done to deserve that?"

"That's just the thing, I don't know. My mom was a great person, she believed in those that others didn't. All she wanted was the truth and she wasn't bothered by the past. If they didn't do it then she'd fight for them, no matter who they were. So I really, really don't know why she would have been killed like that!"

"We'll figure it out sweetie, if you want to. If not then I'll be here for you, no matter what. But the minute you want to look back into this, you've got me, okay?" She asked and Kate nodded against her. "And I know you don't see it at the moment but what Castle did, he did for you. He loves you, Kate and he's the best thing that's ever happened to you."

Kate sighed. "I know, Lanie. I know this isn't his fault and he was just trying to help but he wasn't there when I spent every waking minute looking for something. I was a mess back then and he comes in with his 'contacts' and finds something straight away. How does he even know the best forensic pathologist in the city in the first place? Ugh, he infuriates me sometimes."

Lanie chuckled. She'd been friends with Kate long enough to know that even though she said all these things about Castle, she loved him really. She was just too damn stubborn for her own good sometimes. "So, what did you do?"

"I told him we were done and came straight here. I had to stand by my word, Lanie. I need time away from him. I know what he did was for me and I'm in a way glad that he found something but at the same time I'm incredibly pissed off that he went there in the first place."

"Well you wanna stay here for a couple of days? I mean I know you still have your apartment even though you spend practically every night at his place but I thought you might want some company?" Lanie suggested.

"Thanks, Lanie, but I'm okay. I'm just gonna head home and have some me time. I'll call you tomorrow?"

"Sure, bye sweetie." Lanie said as Kate headed out of the apartment.

"Lanie was kinda on your side, you know." Kate tells Rick.

"Oh really?" Castle asks. He'd always assumed Lanie took Kate's side on that one, especially with the frosty reception he received from her when he went back, anyway.

"Yeah. She didn't exactly go against me and my decision or anything, she just told me you'd done it because you loved me and you wanted to help."

"I..how did she know I loved you?" Castle asks. He hadn't told Kate at that point.

"Apparently it was written all over your face every time you saw me.." Kate says with a smirk.

"Hmm, well I'm pretty sure it was you that was into me first, anyway."

"Castle. We're not having that argument again. Not now!" Kate laughs, god they'd had that argument so many times, neither of them ever agreeing with the other.

"You'll admit it one day."

"Castle, it's been like six years. And we've been married for nearly three. Don't you know me well enough by now to know I'm not giving in?"

"Yes, yes I do. And it's one of the things I've always loved about you. Even though I actually found something when I looked into your mothers case, you still stood by your word and walked away, you weren't giving in easily."

"I'm sorry." Kate whispers.

"Hey hey, I didn't mean it like that! I was impressed, actually. That you had the strength to walk away and not go back to how you were. I went too far, I realised that, but you have this incredible strength and willpower that is so admirable, it makes you so special."

The rest of the week passed in a blur for Castle. He'd tried calling Kate so many times he was surprised she hadn't hit him with a restraining order. Left so many messages her inbox was probably full. He knew he shouldn't have done it, she'd specifically asked him not too but when Murray got back to him saying he'd found something, he had to know what - he was a writer after all, liked his stories to have meaning and endings. He wouldn't have told Beckett unless he absolutely thought she had to know, he didn't want to lose her. But he couldn't have kept that a secret, no way. It had a taken a huge amount for Beckett to trust him up to this point and he knew by going behind her back he was violating that trust but he wouldn't have been able to live with himself if he'd kept that quiet.

He couldn't sleep and couldn't write. He had Gina breathing down his neck every five minutes for the rest of the Nikki Heat novel he was almost done with..he just had to write the final chapter and it was done, but he didn't know what to write. How could he give the book a good ending if he and Kate were still in limbo? Didn't seem right. So Gina would have to wait, it's not like he hadn't given them over twenty bestsellers already, surely they could wait another few weeks.

Alexis even offered to talk to Beckett, bless her. The two of them had grown pretty close in the few months he and Kate had been dating and he could tell she missed her too. She comforted him though, even after he told her what he'd done. She went all parental on him for a moment, telling him off for what had happened but she'd made them ice cream for breakfast and she was there for him.

And then the call had come from Gina - the press wanted a photo shoot and interview to go with this new book - the one he hadn't finished yet. Gina tried to put them off until the book was complete, but they said they wanted it now and they'd just run it when the book was published. Castle was petrified. It had been six days since he'd seen Kate. She hadn't returned any of his calls and he knew better than to visit her apartment or the precinct. But this shoot had to be done at the precinct and they wanted to speak to the inspiration behind Nikki Heat too. Oh Beckett was going to love this.

So the next morning found Castle with two models wrapped around him whilst Beckett shot him scathing looks from her desk. She hadn't said a word to him that morning but hadn't looked surprised when he turned up, so he figured the captain had told her the plan. And then they got a body and he managed to convince her to let him and the reporter tag along, much to his relief. He hadn't seen her in a week, he was going to take every opportunity he could to win her round again.

It was Alexis, in the end, that had made him realise what he had to do. He needed to apologise. Properly. So he headed down to the precinct to see she was still sat at her desk, finishing off the paperwork from their - her - case.

He knew this might not even work, that she might not ever talk to him again, but he had to give it a shot. "I'm sorry. What I did was wrong. I violated your trust, I opened old wounds, and I did not respect your wishes. And if we're not gonna see each other again, then you deserve to know...I'm very, very sorry."

And as he'd turned to walk away, a miracle had happened. "Castle." She'd called, "I'll see you tomorrow." And she had. She called him the next morning when a body dropped and it had been tense at first, but they'd got round it. He cooked her dinner that night and he knew then that he was the luckiest guy on the planet.

"I never did find out though, why did you forgive me?" Castle asks.

"Lanie, mainly. She made me realise that what we had was not worth throwing away over my moms case. After I realised you'd done it to help I kinda had to forgive you. Doesn't mean I wasn't still angry though, but I think you learnt your lesson." She replies.

"Yes, yes I did."

"But I meant what I said - we wouldn't have got this far if it wasn't for you." She says as she kisses him softly. "Now come on, we've got to get up and go to work."

A/N: so, what do you think? Please let me know what you did and didn't like and I'll try and take some suggestions on board for future chapters!