This accidentally happened when I was working on my other fics. Two-shot, the second chapter will be up in a few days.

Always AU-Only differences are that Beckett didn't quit, Esposito wasn't suspended and Martha and Alexis don't show up in the morning.

Disclaimer: I don't own Castle or the characters.

Richard Castle hadn't woken up feeling this great in a very long time. He didn't want to open his eyes as visions of Beckett from the previous night flashed through his mind. He stretched out, eyes still closed, reaching for her. When he felt nothing but cold he rolled over, his arm knocking the pillow from the other side of the bed onto the floor, knocking the note Beckett had left him with it.

He looked around and there was no sight of her in the room or any evidence that she'd ever been there.

"Beckett?" he called out but there was no response. He dropped his head back onto the pillow, his good mood vanishing. Where was she? Had she snuck out after he'd fallen asleep or waited until the morning? Had she just left for work but hadn't wanted to wake him or did she regret what had happened between them?

He lay in bed for a while after that, just thinking. He considered texting her but decided against, wanting to have the conversation he assumed was coming in person. If she was just simply at work and had left him sleeping then he would've just texted her but he wasn't sure that was the case. If she did regret what had happened last night, if she didn't want him, she'd have to tell him to his face, she wasn't getting away with it that easily. And he was going to fight for her too, try to convince her that what had happened wasn't a mistake and that they could be great together.

He loved her and he was going to prove it to her. With that thought in mind he finally got out of bed having decided to go into the precinct to find out exactly what was going through her mind.

Castle felt better when he finally did show up at the precinct later that day, anxious to see her, but his confidence left him as soon as he laid eyes on her. What was he meant to say? Just go up to her and say "I love you" in the middle of the crowded precinct? He could ask to speak to her somewhere more privately, but what if she said no? Or said yes but then told him she wanted to forget last night had happened and return to being friends? Castle didn't think his heart could take that right now and if he said nothing, he could at least for now pretend that there may be more of a future for them than just being partners at work.

XXX

Beckett had been waiting for Castle all morning, wondering what was taking him so long to arrive at the precinct. Should she text him? He would've texted her if he hadn't been coming in, right? She was just about to text him when she looked up and saw him in front of her.

And immediately she could tell something was wrong. She expected to see him happy and smiling with coffee in his hand when he arrived and while there was coffee, he certainly wasn't smiling. The look he was giving her was not the one she wanted to see, the one where he looked at her with such love and happiness that she had no doubt about how he felt about her. She thought maybe she did see that same love in his eyes now but it was hidden behind something she couldn't quite decipher and there wasn't a trace of happiness.

Hi," Beckett said, with a smile that didn't quite reach her eyes as she tried to figure out exactly what was on Castle's mind.

"Hi," he replied, handing over her coffee before taking his own seat at her desk.

This wasn't anything like what Beckett had expected when he arrived this morning. She expected jokes, and happiness and flirting and Castle trying to get her alone so he could at least kiss her. But none of that was happening though, he just sat their quietly playing on his phone while she did paperwork.

Beckett was about to say something, ask if they could speak alone because it had been over an hour since he arrived and he had said hardly a word and she couldn't stand not knowing what was wrong with him. Had she done something wrong, something that upset him or did he just simply regret what had happened last night and wanted to pretend like it had never happened?

But then her phone rang and she lost her chance. She ended the call after noting down the crime scene address but now there'd be no time for talking because they had a body, although there was the car ride to the scene which would be a perfect chance to talk to-

"I'm going to ride with Ryan and Esposito," Castle said, cutting off her thoughts and making her chest tighten because it was looking more and more like he regretted last night and she didn't know how to handle that.

"Ok," Beckett replied, before quickly giving the boys the address and saying she'd meet them there because she couldn't bear to look at him anymore and see the unknown emotion in his eyes.

XXX

He didn't like her leaving like that, didn't like the hurt look in her eyes when he told her he was going to get a ride with the boys to the crime scene but he just didn't think he could handle being alone with her right now. Just looking at her brought back memories of last night which was quickly followed by wanting to touch her again as well as the thought that he may never be able to again, they may never get a chance to be together and so he decided that being apart from her for at least for a little while would give his heart a break.

XXX

The crime scene was okay because they had distractions, Lanie giving them details and talking to the witnesses but now back at the precinct there was nothing to stop them talking. But this was a conversation that Castle didn't want to happen here where there wasn't much privacy and he didn't really even know what he was going to say so he stuck close to Ryan and Esposito to avoid having to be alone with Beckett.

Beckett tried several times to speak to Castle but he kept deflecting, saying he was busy and that they could talk later.

Beckett was getting frustrated now and just wanted to know what was wrong with Castle. And she was also getting worried, surely he didn't regret what they'd done, the step in their relationship they'd taken. He was acting strange and Beckett wanted to know why.

She was relieved when they got to the stage where no more work that could be done today as they were waiting on the lab so Gates told them all to go home early. Castle almost invited Beckett over to the loft to talk but he needed more time. More time to formulate a plan, figure out exactly what he was going to say, which arguments he could use to show Beckett they should be together, that they'd be great together. This morning he'd been so confident about what he was going to do but now he realised he didn't know exactly what to say and he at least wanted some time away from her to find the perfect words to make her see what he does.

"Castle, can we-"

Castle cut her off, "can we do this later, after the case?"

"I-" she didn't get to finish her sentence again.

"I'll see you tomorrow," Castle quickly replied before turning and heading towards the elevator. And if he hadn't have been so preoccupied trying to figure out what he was going to say in their future conversation, he would've seen the hurt look in her eyes and knew he was making a mistake leaving her like this.

Thoughts?