A/N: glad you're all enjoying this story, thank you for the feedback so far! Oh, and 71 followers after just two chapters? That's a record for any of my stories I think, thank you!

After their girly talk about Kate's feelings for Castle - where Kate had admitted much more than she would to anyone else, Charlie announced she was going for a nap. The jet lag was catching up with her, she'd flown from Cambodia to London, where she'd done a few touristy things for a week before flying back to New York, but given that it was now 6pm, she needed a couple of hours to catch up before sleeping properly tonight.

As much as Kate would have liked to crawl into bed too, she knew she had to speak to Castle. Digging her cell out of her bag, she pulled his number up onto the screen and hit dial.

Hey answered after a few rings. "Beckett, we got a body?" He asked.

"Uh, no. I er, said I'd call.." Had he forgotten? "And so I am..to talk. About.." The fact that I pretended I didn't have a sister for the past four years, she said silently.

"Charlie. Right. Have you eaten?"

"Not since lunch but that was kinda late so I'm not hungry," she replied, just wanting him to get on with the ear bashing she was expecting.

"Yeah, me either..not sure why I asked. Wanna meet for coffee then?"

She agreed and they settled on their favourite coffee place, just a few blocks from the precinct. Beckett applied a little more mascara and blusher to make herself look a little more alive, scrawled a quick note for Charlie in case she woke up before Kate got home and grabbed her bag and keys, heading out of her apartment to go and meet Castle.

He had arrived before her and was waiting at a table in the corner, coffee already on the table.

"Hey," she smiled, slipping into the seat opposite him.

"Hi," he smiled back, "I already ordered, didn't think you'd mind."

"No it's fine, thank you." Small talk. They were making small talk. C'mon Beckett, you've spent practically every day with this man for four years, surely you can make decent conversation?

"So, how's Charlie?" Castle asked, bringing up the reason they were here right now.

"Sleeping," Kate replied, "jet lag finally catching up with her, I'll wake her and make her eat when I get home and then let her sleep the rest of the night."

"Ah, yeah. Jet lag isn't nice," Castle sympathised, having spent way too many hours travelling to Europe for book tours and the like.

"Castle, I'm sorry. I should have told you I had a twin sister.."

"Yeah, you should have, but you didn't. And I'm not going to say I'm not a little upset and angry that you didn't say anything but if I know you like I think I do then you had your reasons. And I know you're a very private person but I'd like to think those walls are almost down and if you wouldn't mind, would you be able to explain why you didn't say anything?" Castle didn't normally ask Beckett things like this, she wasn't a person who gave information about herself easily and almost never on someone else's terms, but he felt he had a right to know about this. They weren't just partners anymore, they were a hell of a lot more than that and he deserved an explanation.

"Er, yeah, I guess you deserve that at the very least," she said, taking a sip of coffee. "Like Charlie said earlier, we took moms murder differently. We'd been inseparable up until then, we did everything together when we were teenagers..even down to having a crush on the same guy when we were sixteen," she smiled at the memory, "god, we argued like crazy over that.."

"Who got the guy?" Castle asked, "cause the Kate Beckett I know wouldn't let anything or anyone stand in her way of what she wanted."

"Neither of us," Kate admitted. "We both decided at the same time to let the other have the chance and in the end neither of us wanted him. I think he'd already moved onto Maddie at that point though.." She smiled again, Maddie would be ecstatic that Charlie was back in town, although she'd been Kate's best friend, she'd been pretty close with Charlie too.

"And then when mom was murdered, everything changed. You know what I was like from what I've told you but Charlie didn't want anything to do with the investigation. We were both just as close to mom, but after the funeral Charlie managed to move past it and get on with her life. We were both at Stanford, couldn't even go to separate colleges..except she went back and I didn't. I think that's what changed it for us, we'd spent practically every day together until then and after that I only saw her when she was home for the holidays..but I was working most of that anyway, desperate to prove myself as a cop."

"It must have been hard," Castle said, "having a twin is a special bond and after 19 years of being together you just weren't."

Kate nodded, "yeah, you're right, it was hard, but it was the only way. Charlie couldn't stick around and watch me get sucked into that case, we hardly even mentioned mom when we were together because it would just cause arguments. I didn't just lose my mom that day, I lost my other half," she whispered, tears threatening to spill over.

"Oh Kate," Castle reached for her hand and was shocked when she didn't pulled away at the contact. "I know I asked for this but I don't want to upset you..you don't have to carry on." He wanted the story but he wasn't going to force it out of her, he cared for her too much to upset her on purpose.

"No, it's fine," she took a deep breath, "you deserve this and I'm going to tell you. After she finished her degree, she flew to London - she's got a teaching degree, finished top of her class and she combined it with English, so after London she flew to Thailand to teach English over there. I don't know if you noticed earlier when I used her full name, but-"

"Her middle name is Harper. Same as Alexis' - for Harper Lee, I'm guessing, that's why it's Alexis' middle name anyway."

Kate smiled, of course he'd get the literary reference. "Yeah, same as Charlie. It was one of my moms favourites and both of us were brought up on good books. Guess we both got our love of reading from my mom, it's just Charlie decided to study it too. If you give her a chance, the two of you will get on so well, you'll have so much in common.."

"Woah, what do you mean if I give her chance?"

"Well," she shrugged, "you have every right to be angry with me, just don't miss out on the chance of a great friendship with my sister because of it."

"You really don't get it do you?" She shot him a puzzled look. "Kate..the way I feel about you..I'm not going to say it because I know you're not ready for it, but yeah I'm a little angry but not enough to throw away the last four years."

"I don't deserve you," she muttered. "Anyway, she's been gone five years and now she's back..I think we both needed those five years apart to realise how much we need each other."

"Mm, it happens like that sometimes, you don't know what you've got until it's gone." Kate rolled her eyes at the cliché. "What? It's true," he said smiling at her.

"Do you wanna come over tomorrow?" Kate blurted out, "get to know Charlie a bit better?"

"Sounds good, but why don't you both come over to mine? Alexis will be there and I'm sue she'd love to meet Charlie.."

"Okay, great, I'll let Charlie know," she smiled at him, she didn't know what on earth she'd done to deserve a guy like this but she wasn't giving him up, not ever.

"So, how similar are you? Besides the looks thing, I mean."

"We're actually the complete opposite, you'll figure it out soon enough," she laughed, "but yeah, we are literally identical in the way we look. Even down to her lightening her hair whilst she's been gone, I didn't know that, we look exactly the same again. If she had been here when we met you'd have been able to tell the difference immediately, her hair was never short like mine, but now that I've grown mine out again I guess we could pass as one another!"

"Yeah, I thought I was dreaming when she walked into the precinct earlier," Castle said, shaking his head, it had been so surreal.

"All your fantasies come true, hey Castle," she teased with a grin.

"Oh god, don't," he groaned, he wasn't about to admit the inappropriate thoughts that had flittered through his mind upon learning the woman of his dreams had an identical twin. "Seriously though, you could have a million identical sisters and I'd still only want you."

She ignored his remark and responded with another teasing joke instead, "what, one Beckett woman too much for you to handle?"

"More than enough," he replied with a playful smile.

"Yes well, speaking of other Beckett women, I should get home and wake her up. Maybe I'll pick up Chinese on the way so she doesn't hate me too much for disturbing her beauty sleep!"

"Yeah, we have been here a while, I should get back to Alexis."

"Thank you, Castle, for understanding and not hating me for not telling you."

"I could never hate you Kate, never."

Kate picked up Chinese on the way back and found Charlie awake when she got home.

"Hey," Kate said, closing the front door behind her, "I was coming to wake you. I brought Chinese if you're hungry."

"Mm, yeah I am a bit actually. So, how did it go with Castle?"

"Pretty good, actually," Kate admitted. "Better than I thought. He's invited us both round to his tomorrow if you wanna go.."

Charlie raised an eyebrow in the same way Kate did but didn't comment on it, "yeah, sounds good."

"Cool, his daughter will be there too-"

"Wait, he has a daughter?"

"Yeah, Alexis, she's eighteen. Incredibly smart, a hell of a lot more responsible than you or I were at that age and the best kid anyone could ever wish for. Seriously, if I didn't know better then I'd question whether she was Castles or not."

"Right. And her mom?"

"Lives in LA. She's an actress. Doesn't see Alexis that much, poor kid, but Castle is an incredible father, she's a lucky girl."

"You know," Charlie said, "it's a good job you didn't deny being in love with the guy, it's written all over your face."

Kate blushed. "Shut up and eat your dinner," she grumbled.

"Yeah yeah, whatever. So, he doesn't hate you for not mentioning me then?"

"No..he was surprisingly understanding actually."

"Good, cause I wanna talk to him. Did you know that he knows James Patterson? Seriously, that's so cool!"

Kate laughed, seemed like Charlie had been doing some digging in Kate's absence. "Yeah, I've met him a few times. They get together for poker with a couple of other writers when they're all in town, I'm sure he can introduce you at some point."

"Oh my god," Charlie squealed.

"Just don't let Castle know how much you love Patterson, he'll get jealous. Come to think of it, I can't believe it took you so long to realise that it was Richard Castle," Kate said, thinking back to the moment Charlie had realised.

"Well you know me, I'm not into the crime thrillers - that's your thing - Patterson excluded, of course. But I have read his latest ones, I still can't believe they're based on my sister.."

"Yeah, I was a bit like that when he first told me I was his new muse."

"He's been good for you," Charlie stated.

"Yeah, he is good for me."

"You're a different person to when I left. Not just the hair, but now we look exactly identical again! No, there's this aura about you, you just radiate happiness and it's refreshing actually. You were a mess when I was at Stanford and I know you sorted yourself out but you weren't like this when I left, I'm assuming it's him?"

"Yeah, I think it is. He uh, knows everything, Char," Kate admitted. "About mom, I mean," in fact, he knew more than a Charlie, but she didn't want to bring that up now, she'd just got her sister back, she didn't want to push her away again.

Charlie was silent for a few minutes. Kate hadn't been the only one to change in the past five years, she herself had grown up and she wasn't going to fly off the handle at Kate for bringing up their moms murder, but it really showed how much Kate had changed if she had told Castle everything. "I'm glad," she said eventually and Kate looked at her, confusion on her face. "It's not good to keep it bottled up Katie, and you couldn't talk to me about it so I'm glad you had Castle, he seems like a great guy."

"He is, he's the best. And the two of you are gonna get on so well," Kate was practically bubbling with excitement, "for a start you both love books and I've never met anyone who can analyse a story like Castle. Alexis' middle name is the same as yours, for the same reason too."

"Ah, well I do love a man who knows his literature," Charlie teased

Kate narrowed her eyes, "hands off Charlie, he's mine," she warned and her sister just laughed.

"Wouldn't dream of it, Kate. The two of you are perfect for each other. I've been back for an afternoon and I can tell that."

"Anyway, all we've done is talk about my love life, what about yours?"

"Not exactly a lot to talk about," Charlie grumbled.

"Oh come on, you're not telling me that you've had no interest in anyone in five years?" She had been single when she left and Kate didn't believe there had been no one.

"Well, there was this one guy in London.."

"And?" Kate pressed. Charlie and got it out of her and now it was time to return the favour.

"He was brilliant..funny, charming..ridiculously hot and he was crazy about me but I broke it off when I left England, haven't see him in three years. And apart from that, there's been no one special, nothing they lasted longer than a few months."

"Well, maybe now you're back in New York you'll meet your soul mate or whatever," Kate supplied and Charlie arched her eyebrows again.

"Who are you and what have you done with my sister? First you're telling me you're in love - which, by the way, I never thought would ever happen, and now you're talking about soul mates?"

"Ah, guess I listen to Castle more than I realise sometimes," Kate explained sheepishly. "There's a new detective just started down in robbery, I worked with him a few weeks back, just your type too, maybe I could introduce you?" Kate had never really interfered in Charlie's love life before, but she just wanted her sister to be happy.

"Mm, maybe in a few weeks, I've got a lot to do before I settle back here for good. How's dad?"

"He's good, great actually. He doesn't know you're back then?"

"No, thought I'd suprise him. So he isn't er..hasn't.."

"No, hasn't drunk a sip since he went into rehab, he's done amazingly well, I'm really proud of hm. And he'll be so happy you're back, maybe we should see if he's free for lunch on Sunday?" Kate suggested.

"Yeah, okay..why don't you arrange something and I'll show up and suprise him too?"

An idea was forming in Kate's head. "I've got a better plan - why don't I arrange to meet him and you turn up, see how long it takes him to notice it's you and not me?"

"Oh god, you think we can still get away with it?" Charlie asked with a grin.

"Of course we can, mom always saw through us but dad hardly ever did." The two of them had switched all the time when they were younger and their dad still had a hard time telling them apart, he had been relieved when Kate had had her hair cut short, made it so much easier to tell them apart but now they could confuse him again, especially as he didn't know Charlie was back yet.

"Okay, we'll do it. And you can wait at another table or something, and either come over when he realises or just shock him halfway through when he sees we're both there."

"Perfect," Kate laughed, "oh, wait until we tell Castle our plan, this is so up his street!"

"We can tell him all about it tomorrow, when I get to meet this incredible daughter of his," Charlie said, "now come on, let's go to bed, I'm tired again, stupid jet lag."

As Kate climbed into bed she felt the happiest she had in a while. She was so close to letting Castle in and her sister was home where she belonged, certainly things to smile about. And she was really looking forward to introducing Castle and Alexis to Charlie properly tomorrow, they were going to have a great day.

A/N: so, did I do the Kate and Castle chat okay?! So next chapter will be Kate and Charlie going to Castle's place - should be fun! And then in a couple of chapters time, I shall be introducing my 'plan' ;) Reviews make me happy :)

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