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.

Post ep for 2x24 A Deadly Game

It was good of the guys to put on this little farewell party for him, he thought, it made him feel a part of the team. He was going to miss this, but he had to step away. This way, he could do it without looking like a sore loser, and the book really did have to be finished.

They were laughing at something Captain Montgomery had said when Beckett walked into the conference room, and she picked up on the merriment as she grabbed a beer for herself.

"Ooh, look who's off duty" Castle teased her.

"Yeah, well Castle, I'm not all work" she replied, and Castle was caught by the easy banter and a twinkle in her eye. She seemed lighter, somehow.

Lanie must have also picked up on Beckett's mood, as she gave Castle some advice "don't get into a drinking contest with her, she can take you"

"Thank you," he acknowledged, nodding at Lanie, but stunned anew by this extraordinary creature in front of him. Stop it, Rick, she made her choice, and it wasn't you, he reminded himself, but it was hard, especially when she was right there.

"Oh, I don't need to drink to take him" Beckett replied, voice full of innuendo. For a second, Castle's mind flared with hope, but he stomped it down hard, reminding himself again that she was going away with Demming. Then curiosity overtook him as she asked to talk to him, and stepped outside into the hallway.

When she closed the door, he asked "What's up?"

She looked nervous all of a sudden, like she was trying to find words. This was a look that he didn't see much on Bad Ass Beckett, it was almost like she'd been left in the conference room and Kate had come out to talk to him.

"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". The smile on her face melted his heart a little, before he reminded himself she had Demming.

"Yeah, me too." The last year had been some of the best in his life, apart from his time with Alexis, and it made him feel like he was actually contributing to something, being useful. Well, all good things had to come to an end sometime. Not the end you wanted though, is it, Rick? He needed to make a clean break.

She looked really nervous now, and Castle had no idea why that may be. There was something else in her eyes, something he had never seen before, and it threw him. Most of the time now he had come to anticipate most of her moods, but he was totally stumped what this conversation was about.

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

"Richard, are you ready?"

Gina. Of all the times to interrupt a conversation. He really wanted to know what she was going to say.

"Hey, Gina. Uh, Beckett, you remember Gina, my ex-wife"

"And publisher" Gina put in, shaking Beckett's hand, then linking her arm through his and taking possession – almost like she was marking her territory. There was a flash of something in Beckett's eyes, but it was gone too soon for Castle to identify it - again. He really was off his game. Maybe she was in sync with Demming now. That thought shattered his heart a little bit more, but he was going to be a gentleman about this, if it killed him.

"Yeah, we spoke the other day. Looks like you finally tracked him down."

"Oh, yeah, he's such a little boy sometimes," Gina said, rolling her eyes. "I mean, I don't know why, it's not like I bite… much," Gina added, smiling up at him. Then she continued "We better get going if we don't want be stuck in traffic all night."

"Going?" There was that look in Beckett's eyes again, looking at Castle.

"To the Hamptons" Castle replied, still trying to work out what that look, and the weird tone of her voice meant.

"For the weekend?" She asked again, still reserved, and Gina was quick to jump in "for the summer actually, so I can stay on top of him while he finishes his book."

Beckett was saying something, and he was replying, talking about the nice phone call he'd shared with Gina the night before, but his eyes were cataloguing the facial expressions Beckett was displaying, and filing them directly into his hind-brain. He couldn't look at her any more, he had to get away before he did something really stupid, so he looked at Gina instead, although he really couldn't remember ever having looked at Gina like that before.

"So, I'm sorry, you were telling me something," Castle tried to bring the conversation back to Beckett, even though he didn't really want to hang around too long now that Gina was here. What made him agree to have her come to the precinct to meet him, anyway? Women were all too perceptive sometimes - well his mother certainly was – and he didn't need any grief from Gina about Beckett or it would be a very uncomfortable summer.

Beckett's mouth said "Have a great summer" but her face, and her eyes, were telling a whole other story, and Castle sank even further into confusion, he had no idea what was going on with her today.

"You too," he said, trying very hard not to imagine all the things she would be doing with Demming, curse his writers imagination. Again he told her it had been great working with her, wincing internally at the past tense of that statement. It really was for the best. You keep telling yourself that, Rick.

He looked towards the door of the conference room, where he could see the guys and Lanie watching them through the door, and waving goodbye, as they could see him moving towards the elevator.

The handshake was awkward, and not just because Gina was hanging on his arm. It was almost like the first goodbye after the Tisdale case, and for a moment he was tempted to lean in and at least kiss her cheek again, but there were all too many reasons that was a really bad idea, so he took his cue for a quiet exit.

"See you in the fall?" Beckett called out, when he was almost to the elevator, and he thought her voice sounded odd, stilted, and almost sad. The whole last 5 minutes had been totally confounding for him. He tried to turn around but with Gina hanging off his arm, he only managed to turn his head.

"See you in the fall," he replied, thinking that perhaps by then he would be able to get back to being friends with Beckett, not hurting so much every time he saw her with Demming.

When he got in the elevator, Gina let go of his arm, and started hunting around in her handbag. He pressed the button for the ground floor, and watched the doors close. It almost felt like they were closing on a chapter of his life. Where did that thought come from?

Too soon to have reached the ground floor, the elevator stopped and the doors opened. Someone else was getting on, and it wasn't anyone that Castle really wanted to see right now.

"…Castle"

"…Demming"

Pleasantries exchanged, there was nothing to do but stare at the top of the elevator doors, willing the floor indicator to move faster

"Rick," Gina grabbed his arm again, holding her phone in the other hand. "The Waltons are having their annual Memorial Day cocktail party tomorrow night, and Cherie Tennyson has invited us out on her yacht. Oh, and I heard the little boutique in the village has new stock from Paris-"

Castle was a little distracted, but he managed to listen to most of Gina's ramblings "Relax Gina, we have the whole summer, we don't need to rush around"

There was some sort of weird noise from the other man in the elevator, almost like a grunt or growl. Surprised, Castle turned towards the sound, only to be met with a very solid right fist. For a second, he could see Demming's cold blue eyes behind the fist, filled with fury.

"You son of a bitch, you steal my girl then dump her to take another woman for the summer?" Castle didn't get a chance to even open his mouth before a hard left fist was rammed into his gut.

"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. Don't bother setting foot in this place again, or I will make sure the full force of the NYPD comes down on your worthless ass!" And with that, the elevator doors opened on the ground floor, and Demming walked out.

Castle could vaguely hear Gina prattling on in the background – god that woman just didn't shut up sometimes. There was a very good reason she was an ex-wife.

Then the words that Demming had thrown at him actually registered, and he froze.

What the hell?

A/N: this is my first fanfic, and this story has been in my mind for a week or so now. Please be gentle, but I welcome constructive feedback. Thanks for reading!