A/N: Thanks so very much to everyone who read and reviewed the last chapter, I am absolutely blown away by the response, so here is part will probably be at least one more chapter. I am particularly grateful to those who gave me constructive feedback on both the story, and my writing, your words are very much appreciated.

Disclaimer: I don't own them, and I make no money from this. Like many others, I just like playing with them for a little while.

What the hell?

It was the ding of the elevator door almost closing that brought him back to his senses, even though Gina had already walked out and was looking back at him with impatience. His mind was reeling with a thousand thoughts, all clashing and ramming against each other, fighting for dominance. He really needed peace and quiet – and perhaps a scotch or two – to sort them out, but that wasn't going to happen unless he made some drastic changes to his plans. Starting with the blonde in front of him.

"So Rick, want to tell me what that was all about? Who was that man? Is he a cop? I am sure there are rules about police assaulting civilians, we can get Black Pawn onto that on Monday if you w-"

"No! No, I don't want Black Pawn, or you, involved in that at all. It doesn't matter who he was" Rick said, trying to figure out how we could get rid of her so he could go back to the loft.

"But Rick, who was this girlfriend-"

"I said leave it alone, Gina! Now, I have realised I can't quite go to the Hamptons tonight, so I will get the town car to drop you at home and I will talk to you next week, OK?"

"What? What has changed? It's that Detective Beckett isn't it? You have been spending a lot of time with her and neglecting your writing. I had hoped when we spoke last night that-" She never go to finish what she hoped, because Castle almost pushed her into the back of the town car, and gave her address to the driver, then closed the door.

Castle knew he was going to pay for that later on, but right now he didn't care. He flagged down the next cab and gave him the loft address. If he had glanced back towards the precinct, he would have seen Kate Beckett walk out the door, her shoulders slumped and her whole manner dejected, with a weekender bag in tow.

While the cab was stuck in traffic – the delays of that afternoon had served to put him right into the middle of peak hour traffic – he allowed a few more minutes of thinking about Gina. She had already called his mobile twice in the 5 minutes since they parted, and was obviously very frustrated with the fact that he let them go to voicemail. He could imagine there would be some nasty voicemails waiting for him, in that irritating tone she had when things didn't go her way.

What on earth had prompted him on the phone last night to invite her to the Hamptons for the summer? That was a mistake just waiting to explode in his face. Just because they could talk like normal people for a couple of hours, didn't mean they could – or should – rekindle a relationship that shouldn't have happened in the first place. Obviously between losing Alexis to the summer program, and Beckett to Demming, he had decided he couldn't or shouldn't be alone, and reached for 'comfortable' female company. And Gina was comfortable, in the way of 'better the devil you know'. They did have a history, and had at one time been good together, but it was never love, and he knew that now. Shame that it took him falling in love with Beckett, and having is advances rejected, for him to learn that.

Which brought his musings right back to the main problem, right around the time the cab pulled up in front of his building. He walked through the lobby with a passing nod to Eduardo, who seemed surprised to see him but didn't comment, and straight into the elevator - then straight out again, and heading for the stairs. He'd had enough of elevators for a while, he wasn't ready just yet to re-live the last ride.

Once he got inside the loft, he busied himself for a few minutes with normal activities – changing into comfortable clothes, reheating some leftovers for dinner, and pouring himself a generous glass of wine. He wondered briefly where his mother was, then remembered she was out with some friends and not expecting to be home until after the weekend. Perfect, he could think in peace.

All those tasks done, there was nothing left but to explore the events of the afternoon. On the one hand, he was reluctant to do so, he had almost made his peace with Beckett's choice, and forced his mind and heart to move on. Whatever Demming had said, and the look he saw on her face while Beckett was saying goodbye, dwelling more on his feelings for Kate was just asking for more pain. Unfortunately his writer's brain was clamouring for the story, to dissect every word, every look, every expression, until he knew the truth.

So, let's start with Beckett – Kate. Ever since he had told her he was leaving after the current case, there was a slight shift in the looks she gave him, it was almost like there was uncertainty or doubt in her mind, something that Detective Beckett never showed. And then when she called him out of the farewell party, she seemed to be reluctant but determined to share something with him, something she obviously considered important, judging by the intensity of her gaze, and the way she was fidgeting with her hands the whole time.

And then when Gina turned up, the shock on her face was only barely hidden, but it wasn't until Gina mentioned they were going to the Hamptons for the summer that Castle saw Kate's expression pale and then freeze. He was not sure why, and discounted that look at the time. Kate had turned him down, and she was going away with Demming, so why would she have been so shocked about his plans? Of course, it had only been 24 hours since she had turned him down, so maybe she was surprised he already-

Wow, he was an idiot. She turned him down, even though he had stated the invitation was for friends, no funny business, and not 24 hours later he has another woman on his arm to take her for the summer. Way to go Rick. Way to convince her you are not that Page Six playboy.

And that reminds him of Demming's words.

"You son of a bitch, you steal my girl then dump her to take another woman for the summer?"

"I knew you were a no good playboy the moment I met you, and I have no idea what she saw in you in the first place."

Steal his girl? Castle didn't steal anything, certainly not Demming's girl. Beckett had chosen Demming, so he was quietly stepping away leaving the two of them to their relationship. And then dump her? Well that was even more absurd, as they had never been together, and if he was honest, it had been Beckett 'dumping' Castle as her partner, for Demming. The robbery detective had been up in their floor constantly the last couple of weeks, bringing her coffee, getting into her personal space. Castle's heart broke a little each time he saw them together, and he decided he needed to remove himself from the situation.

So what had happened in the last 24 hours to make Demming lash out and say those things to Castle, and to physically assault him? Demming had always seemed to be in full control, very calm and methodical. Castle might not like him because he had Kate, but he had to admit he was a good detective.

Castle topped up his wine glass, and again made himself comfortable in his office. Some in depth objective analysis was needed. Demming said Castle stole his girl. Which would suggest they were no longer together, and by the term steal it was Beckett who broke it off. Why? She seemed to be happy with him, judging by the stolen kisses Castle witnessed in the precinct. Leave the why for now, move to the next question.

When had she broken it off? It still seemed to be on when he left the precinct that morning to drive Alexis to Princeton. Then when he saw her again as she walked into his farewell party, she seemed lighter, happier somehow. Straight after that, she called him out to talk in the hall, and less than 10 minutes after that he was in the elevator meeting Demming on the Robbery floor. So she must have broken it off with Demming before she came into the conference room. He was still coming back to the why, and it was bothering him. Let's review what Kate said.

"Look, I know that I'm not the easiest person to get to know, and … I don't always let on what's on my mind, but this past year working with you … I've had a really good time".

"So, uhm, I'm just going to say this, and-"

What on earth was she going to say? It was so frustrating that he didn't know, it was like the missing piece of the puzzle. If only she had finished what she was saying, he knew this would all make sense. But she was interrupted when Gina called out to him.

Gina. Obviously whatever she was going to say couldn't be said in front of Gina. What wouldn't she say in front of another woman? Oh. Oh! She breaks off with her boyfriend, flirts with him in front of her colleagues and captain, asks to speak to him privately, and tells him she enjoyed working with him. She was opening up to him again, is it possible she may have wanted to explore another step in their partnership?

And then, just as she is about to do that, his ex-wife turns up, and tells her they are going to the Hamptons for the whole summer. Yeah, he can see how that would have been a shock, and explained the look on her face when she said 'have a great summer'. Damn, he was an idiot. He really should have talked to her about stepping back, about respecting her relationship with Demming, but they never talk, do they? They have perfected communicating in subtext, and she didn't really know that he was interested in her, just as he didn't know that his leaving would affect her this much.

That came down to him again. Apart from inviting her for a debrief after that first case, he had not openly pursued her since, instead enjoying the banter and innuendo they shared. And after he looked into her mother's case and got kicked out of the precinct, he was just grateful to be working with her again. She had moved beyond a conquest to him long since, but not once had he actually told her that. And then of course, there were his dalliances with Meredith and Ellie Monroe, Kyra and Kate's friend Madison. No wonder she didn't let him in beyond working together at the precinct. Once again he castigated himself for missed opportunities.

He could spend all summer thinking about Kate and trying to puzzle out what this afternoon meant. What he really needed to do was talk to her, find out exactly what was going on. And he knew that she would not be the one to reach out to him, especially not the way they had left things. Should he call her? She may not – probably would not – answer. She still thought he had gone to the Hamptons with his ex-wife. While he really wanted to let her know he was still in New York, he really didn't want to get into too much detail with her – or to put his feelings on the line - until he had a better idea where they stood. He decided to send her a text, and seeing as it was already late – how long exactly had he been lost in his own mind? – He figured she wouldn't see it until the next morning anyway.

"KB I am still in NY. Can we talk please? RC"