Beckett wasn't stupid. She could sense that her partner had something really big on his mind, and the tension between them had been growing for days. He had been moody and sullen and his lack of pointless chatter gave away the seriousness of whatever it was he had on his mind. The three years she'd spent with him meant that she was pretty good at reading his tells and the sudden change in his usual demeanour was slightly unnerving.

Under normal circumstances, she would have been curious as to what could have set off the sudden change, but recent developments had Beckett thinking that she was just about 90% sure she knew what had her partner so bothered. The remaining 10% kept conjuring up images of Alexis, or Martha, or God forbid, his beloved lightsaber going missing during some point within the last two weeks.

The chain of events that had led up to this point had begun almost two weeks ago, triggered by an unassuming text message from Josh wishing her the best of luck for her future. That in itself would have been fairly standard; they had decided to try and remain friends after all, but Josh had added an apology in his text.

Spoke to Castle last night, I'm sorry in advance. I didn't know that he didn't know.

Naturally, she'd been mildly confused, but she thought her questions would be answered soon enough, expecting Castle to bring it up when he saw her the day after. Instead, he'd surprised her and was uncharacteristically silent to the point that even the arrival of one of his geeky gadgets failed to elicit anything more than a small grin from him.

And so the waiting game began and had gone on for two weeks. She'd watched him closely in all that time and Castle had yet to give anything away. Her subtle attempts at digging for information remained an exercise in futility as he rattled off excuses about being swamped with edits for his latest novel as a cause for his mood swings. Beckett knew better, though. She knew Josh was a touchy subject between them. She knew Josh had talked to Castle about their inevitable parting of ways and the fact that Castle barely even acknowledged it was setting off all sorts of alarm bells in her head.

"You okay, Castle? You're being very quiet. Again."

He was sitting hunched over in his designated seat, staring intently at something on his phone. He looked up at her, making a show of pondering her question.

"Yeah. It's really nothing to worry your pretty head over," he answered as glibly as he could. Beckett eyed him suspiciously and noticed that he averted his eyes from hers quickly. Three years, and the man still hadn't learned how to avoid the tell-tale signs of lying. Another point in favour of 'something big is about to go down'.

Beckett sighed in frustration. It wasn't as though she didn't appreciate the new, silent Castle, but if he insisted on being there, the least he could do was to alleviate the boredom that came with finishing up the backlog of paperwork she had accumulated.

She let him be for the next two hours but when he started fidgeting around seven in the evening, she knew she had to do something about it. The other detectives who weren't on duty that night had started filing out, and she knew it was about time they both left too. Castle got up from his chair and stretched, making a show of cracking his knuckles knowing that it was something that irritated her to no end. Some things never changed.

Now or never, Katie.

"Do you really not want to talk about it?" She asked him just as he was about to pick up his coat to put it on. Castled paused as he pushed his arms through his sleeves and sighed.

For a moment, Castle wanted to lie and tell her it was nothing, much like he'd done for the past few days. Seeing her now though, curious and looking at him with something that closely resembled concern, made him feel as if she deserved some sort of answer. Besides, all the brooding and mulling over facts, scenarios and what-ifs had him so coiled up tight that he figured it was about time he confronted her about her break up, at least for his own peace of mind.

"I'm a writer Kate," he began slowly. Yeah, he was a writer; there was no way he was going to go straight to the point. A back story always had to be established first. He saw the twitch of confusion flit across her features, and he held a hand up to stall whatever it was she was about to say.

"I'm a writer and all I do is try to figure things out. How, what, why – it's like a constant stream of questions up here," he tapped the side of his head. He sighed loudly and sat back down in his seat, and taking her cue, Beckett sat down in hers as well.

"So … I've been trying real hard, you know, lately, to figure you out. Well, not you you. Because I know I'm never going to really decipher you. But, why you do the things you do, and how – and every conclusion I've come to, it's not pretty."

"Castle, I don't know what you're talking about," she said carefully. Her gut told her she was approaching dangerous territory. She'd never seen this particular clear shade of blue in his eyes and she noticed a glimmer of something that hinted at a larger issue brewing beneath his calm exterior.

"I heard about your break up … from Josh."

Oh. Beckett blinked at his statement and she let out a sigh of relief. It wasn't Alexis, or Martha – well, she was pretty sure if it had been he would have told her much sooner. But hearing him say it out loud was somewhat comforting. It also meant that her suspicions were confirmed and once again her gut had been right.

"I know," she told him with a small smile. She started to reach out towards the hand he'd left on her desk, but his eyes blazed with muted ire and she pulled back.

It was clear that her response wasn't what he wanted to hear. The way he furrowed his eyebrows and fixed her with the steely stare immediately wiped the smile off her face. She could feel the shift in the mood as his eyes switched from a clear, almost melancholy blue to a dark, raging, stormy darker hue and he stood up so quickly that his chair skittered backwards and fell to the floor.

Oh, angry Castle. This was one side of him she'd never thought she'd ever personally experience.

"You knew?" His voice had taken on a dangerous quality; he was whispering with such vehemence that he might as well have been shouting. "You knew that I knew?"

"Look, Castle, I was just waiting –"

"Waiting for what, Beckett?" This time, his voice rose a few decibels. Kate stood up as well, suddenly feeling the need to slightly even out their height difference.

"I-"

"What, Beckett? Waiting for me to beg you for the sordid details? How did it happen, Beckett? Did you dump him or was it the other way round? Was it painful? Were you happy? Was he happy? What, Beckett? What were you waiting for?" He was getting so loud that Beckett was grateful the precinct was halfway empty.

"Castle, stop yelling," she tried. She moved towards him, but the angry glare he sent her way stopped her in her tracks.

"Am I not good enough of a partner for you to tell me these things? Is that it? Because you know what? I thought we were past that. You can't say things like you're a one writer girl, or take me out to watch movies, or have drinks or have hot dogs – and pretend that you don't know what those things do to me!" He leaned in towards here and grabbed her bowl of M&Ms and hurled it towards the other end of the room.

Kate flinched at the sound of the glass shattering and licked her lips nervously. She'd never seen this side of him before, and it made her nervous. He wasn't done though.

"And now you're telling me you knew that I've been sitting here with this piece of information eating at me from the insides for weeks – and you smile at me as if … as if it means nothing to me? Beckett, I keep thinking about reasons; reasons why you'd keep something like this from me and every conclusion I end up with is that I'm not good enough. And that hurts me so much."

"It's never been about you, dammit!" Kate yelled back. "Not everything in the world revolves around you, and your life and your –"

"But you do, Kate! You're every - I can't figure you out Kate," he ran his fingers through his hair and turned away, effectively blocking her view of him.

"You don't have to, Castle. I never asked you -"

Castle whirled around to face her again, and she noticed his balled fists by his side. Fists that had punched the lights out of Lockwood for her, fists that she'd caressed and bandaged and – Oh god, she realised with trepidation, she'd done this to him.

"I thought I was being there for you, your dutiful partner, being your friend, when your boyfriend couldn't. I let myself think that it was okay that you were going to go home to curl up in someone else's arms as long as you were happy. I was ready to let you go."

"And it hurt so much, that after everything we've been through, you still chose him, and he can't even make time to go watch a movie with you!" He slammed his fists onto her desk, sending papers flying everywhere and Beckett moved forward instinctively to stop him before he did more damage.

"So I just waited patiently for you to see me, to see me, right in front of you because dammit, Beckett I'd wait for the world to end for you, only to find out that – what? He's been out of the picture for ages, and you didn't even have the decency to tell me. Why is that?"

"Castle-"

"See, you want to know what I think? I think you were afraid of what I would have done. Is that it? Afraid that if I knew you were single again, I was going to come and sweep you off your feet, because God knows I haven't made it obvious enough that I absolutely fucking adore you. So was that your way of telling me to back off? Make me believe that you were with him so I wouldn't make a move on you, and you can still be free to string me along to your stupid movies and drinks and hotdogs and –"

"Castle , please-"

"No, Kate, tell me. Tell me what your big plan was. Hope I'd get tired of following you around and just give up and leave you alone? Because honestly Beckett, if you wanted that, if all you wanted was that, you only had to tell me. One word from you, and I'll be gone. You tell me we're over – and I'm out of your life for good, because honestly Kate, I don't think I can keep going like this."

It took a while for Kate to realise Castle had stopped yelling. The words were still reverberating through her head, his passionate outburst ringing in her ears. Her heart was racing so fast, it felt as though it was humming a single monotonous tone, and she felt so out of breath, as if she'd just run a marathon and – where'd he go?

She had closed her eyes for a second in an effort to calm herself down and the second she reopened them, Castle was gone.

"… I'm out of your life for good, because honestly Kate, I don't think I can keep going like this."

Crap.

Damn.

Oh. Crap.