Author's Note: This idea came to me really randomly while I was watching Dr. Horrible's Sing-Along Blog (I don't even know, they're not related in any way) so here it is, all in fan fiction form. This will probably be a two- or three-shot, depending on how the story comes to me. Hope you like it. Drop a review, hmm?

Summary: "So, I was thinking – " "Yo, Beckett!" Seriously, Esposito, now? Caskett.

Disclaimer: No, I do not own Castle, though I'm sure you may have thought that. Yep. I don't own Dr. Horrible's Sing-Along Blog either, and I'm really anxious for the sequel. Hurry up, Joss Whedon.

"Hey, Kate."

The way he says Kate makes her feel all bubbly inside, but she can't let that show now. They're at work. Yes, they and work, this is practically Castle's second job now. Castle makes his way towards her desk, and sets down her daily coffee. She smiles, because oh – it's just so sweet how he's managed to bring her a coffee almost every day for years.

"Hey."

Castle mirrors her smile at the returned greeting and plops down into his chair. "Whew, got anything on the case?"

Beckett's smile falters, because this case is just so extremely difficult and stressing. Three murders, too-many-to-count twists, so many suspects – and they all lead back to square one.

She sighs, and shakes her head. "No. The license plate that Ryan ran – nothing. Nothing important, anyway."

Castle sighs as well, slumping a little further into the chair. Beckett knows that this case has been getting to him because of the way he isn't as bouncy anymore; because he doesn't spout out hundreds of theories in just a matter of seconds. She badly wants to just reach out with her hand and smooth out his furrowed brow – but she doesn't. She can't. Not when they're in the middle of a bullpen with a swarm of police officers bustling this way and that.

Suddenly, the writer jumps up. And when Kate gives him a weird look, he gently sits again, a bright something gleaming in his eyes.

Beckett raises an eyebrow, waiting for Castle to start.

"Listen. This case has been hard on us, and we kind of need to relax for a moment, right?"

She tilts her head ever so slightly, a small smile starting to form on her lips.

"So, I was thinking – "

"Yo, Beckett!"

She shuts her eyes tightly. Seriously, Esposito, now? Now of all times, when Castle was supposedly going to ask me to dinner or something else sort-of-kind-of romantic like that?

Before anyone could notice, Beckett opens her eyes again, not wanting anyone to notice her frustration at being interrupted during a long moment with Castle for, what, the gazillionth time?

She lets out a barely audible huff of breath, which Castle catches just in time to quirk up his mood after the interruption.

"Umm… you okay?" Esposito asks, acting hesitant, but Beckett knows he's smirking. And she thought the detective was rooting for the moment when Castle and her got together, yet he and his partner were always finding some time to butt in with new information that usually doesn't end up anywhere.

She glares at him, and nods curtly, obviously displeased.

"Okay, so, me and Ryan were looking through Dan Burton's phone records again, and we saw something we didn't see before. He called this number," he points to his paper, "four times during the week before the first murder, each lasting under two minutes."

She nods.

"But," Castle says, "it could be a coincidence. Four times – that's not really much. He could've been calling a pizza shop or a take-out place or something."

"Yeah, but we thought it wouldn't hurt to check, especially at the spot we're in right now."

Beckett sighs. "Yeah, you should see to that. This case is really irritating me. Hope you find something."

Esposito gives a half-hearted smile and turns around, leaving for his desk.

They finally close the case, after checking out the mysterious phone number.

And boy, does Kate sigh in relief.

She feels so much better. The burden of the case has finally lifted off as she told the victims' families that the murderer was caught.

But – she's still kind of hoping. She's waiting for Castle to finish whatever he was saying before, before they were interrupted by ugh Esposito. So now, she waits.

And Beckett doesn't have to wait long. As she sits at her old, worn desk, filling out the annoying-paperwork-that-Castle-doesn't-help-with, he comes. Castle saunters through the bullpen, coming back from God-knows-where-he's-been. She tries really hard not to smile, not to let her emotions seep out of her facial pores (what?), but it's really hard not to when the man she loves (again, what?) is coming towards her with that sly grin that crinkles his eyes in that beautiful way (oh my goodness what?).

"Kate!"

He looks so delighted, and Beckett tries really hard, again, not to smile. But she does.

"Hmm?"

"I feel so… refreshed. That case – it's finally over."

"You know, you could've stayed home. You didn't have to be here almost 24/7."

"But I had to. I wanted to. And, are you saying that you don't like me being here?" he gasps, an overly dramatic expression falling over his face.

She doesn't reply to that. She really should've, said something like you irritate me horrendously but she doesn't, because really, he doesn't. Did that make sense? She doesn't know. She doesn't care. All she cares about right now is how Castle's lips quirk up at her speechlessness. And oh, those lips –

"So. Mind if I finish what I was going to say before?"

"Go for it," she says, smiling softly.

"Okay." He clears his throat, as if he's getting ready for a speech (oh, no, not a proposal, right? …right?). "I was thinking. Want to… go out, with me? To somewhere, to dinner," he stutters, as if he isn't sure of what he's saying.

Kate bites her bottom lip, but the smile flows out anyway. He's so cute, so sweet. "Uh, where is that somewhere?"

His eyes widen. He can't believe she hadn't said no yet. Ohmygodwhatifshesaysyes – He still needs to answer her question. "It's… it's a secret. A surprise."

She lifts an eyebrow. "You know I don't like surprises," she reminds him, her regular Beckett voice back.

He jumps, as if he'd been hit or something. "No. I mean, yeah, I know. But trust me. You'll like this one. It's awesome."

(He feels so himself again to be using the word awesome without burly gang police lecturing him about being a grown man.)

Kate smiles. "Okay."

Castle freezes. What? "What?"

Beckett lifts an eyebrow again. "I said 'okay.' Or do you want me to change my mind?"

"Oh. Oh. No, no, no. Okay. Okay. What? Okay?"

She smiles, because she thinks that his stuttering is adorable. "Yeah. Okay."

"You'll… you'll go out, on a date, with… me?"

"Yeah, Castle. Unless you want me to say no, because – "

"No! No, no, it's good. It's all good. Let me just… get this straight…"

"Castle."

"Shutting up now."

Thoughts? Reviews are appreciated. Especially if you want to know what happens next. *wiggles eyebrows*