Season Four AU: Pre Couple – Kate has been having nightmares and keeps showing up at the loft / calling castle over to her apartment in the middle of the night to comfort her.

a/n: strayed a little bit from the prompt, sorry about that. I imagine this taking place early season four. Also (loosely) took inspiration from the following lyrics as well:

"One night he wakes, strange look on his face

Pauses, then says, you're my best friend

And you knew what it was, he is in love"

"Kate," Rick answers into the phone, his voice rough with sleep. "It's 2 in the morning – are you ok?"

He hears her breathing, but she doesn't answer.

"Kate?" He asks, his concern beginning to grow.

"Yeah, you know what, I'm sorry it's late I'll talk to you-"

"Kate, no, what's wrong?"

"I just- I had a bad dream, that's all." He can tell she's trying not to cry. "It's fine, I just needed to hear your voice, sorry."

"I'm coming over."

"Castle-"

And then the line goes dead.

Fifteen minutes later and Kate is opening the door to her partner.

"Castle, I'm fine." She mumbles to Rick as he pulls her into a hug.

"Kate, your eyes are puffy and the remnants of your makeup is smeared, I can tell you've been crying. Now why don't we sit down and talk about this dream of yours?"

She sighs but doesn't ask him to leave, which he takes as a good sign, so he releases her from the hug and takes her hand in his, leading her over to the couch before sitting down and pulling her into him. He sits there and watches her, his eyes full of patience as he waits for her to begin talking.

"I-" She takes a breath. "Instead of me being shot at Montgomery's funeral it was you." The tears are back, flowing heavy down her cheeks when he pulls her in even closer, tight enough that she thinks she may stop breathing. He runs his hands through her hair as she sobs, clutching her to him as if he's the one who needs her, not the other way around. He presses kisses to her scalp and whispers sweet nothings to her until her breathing evens out and she's calmed down.

"I was so scared, Castle." She murmurs, so quietly it's almost in audible. She's quiet for a moment before continuing. "I'm so sorry."

He pulls away enough to look at her. "Hey, shh," He whispers, brushing a stray hair away from her face. "What are you sorry for?"

She looks down at her lap as she answers. "For leaving you; you had no idea how I was doing, you didn't even know if I was alive. I told you I would call, but I- I just couldn't. I was too scared, but Castle, I can't even imagine what you went through over the summer."

"Kate, hey, it's okay." It wasn't, but he knew telling her that right now would do nothing but make her more upset.

"No," Her voice is raised, she's looking at him now. "It's not okay, why won't you just admit that?" She stares at him, the exasperation clearly etched onto her face.

"Okay, you're right, it's not okay." He replies solemnly. "But there's nothing we can do about that now, so there's no point lingering on the pain, is there?"

Kate stares at him for a moment, then shakes her head and almost immediately she's back hugging him.

"Thank you," She whispers, gripping him even tighter. "For everything."

Rick manages to loosen her hold on him briefly, allowing him to steal a glance at the clock.

"Hey, it's almost 3, why don't we get you to bed."

She gives him a weary smile, nodding in agreement.

"Are you staying?" Kate asks, turning to face him, as she leads him blindly through her apartment and into her bedroom.

"I don't know, I should probably get going."

"Oh, yeah, okay." She stops and gives him a small smile and tries to hid the disappointment in her response, but really, all she wants right now is for him to stay with her; to hold her when the nightmares come, whisper calming words into ears and press kisses to her scalp until she's okay.

He notices her disappointment though, the same way he notices everything about her, so he questions her. "Do you want me to stay?"

"If you have to go, then go." She tries to remain nonchalant about it, but right now she doesn't really give a damn if she's coming across as needy. He's her partner, the person she trusts, cares about, and loves more than anyone. She needs him right now. "But if you can stay, please do."

She's already turned back around, continuing on the path towards her room, so she misses the grin that's gracing Rick's face right now, which he is grateful for because if she were to see how happy he was about that statement, he knows that he would never live it down.

—

She stays asleep, for the most part, until around 5:30 when she's awoken by Castle rubbing her back and whispering something in her ear that she can't quite comprehend, so she rolls over and stares at him, eyebrow raised.

"Oh, good, you're up."

"I am now," She grumbles. "Want to tell me why?"

"You were having a nightmare."

"Oh," How sweet of him "Thanks."

"Did you want to talk about it?"

"Honestly, most of the time I don't remember them. I didn't even realize I was having a nightmare when you woke me up."

"That's good."

"Yeah, I guess it is," She smiles at him. "Can we go back to bed now?"

"Oh, yeah, sorry." Rick lies back down and rolls onto his side, opening his arms out to her. "Come here."

She shifts towards him, positioning herself so that her back is flush against his chest. He wraps his arms around her torso, pulling her in as close as her can, resting his nose in the nape of her neck, breathing her in. Why couldn't she just tell him how she felt about him so he could stay with her like this every night? You know why Kate. Yeah, she does. She knows that she needs to get better first, that she needs to be able to tear down that wall before she can start a relationship that she wants, well, needs, to be successful. You know what? I'm done waiting.

"Stop thinking so loudly." He murmurs against her skin, pulling her out of her thoughts.

"Sorry." She mumbles.

"What were you thinking about?"

She turns in his arms so she can face him, leaving his face only inches from her own. She smiles at him, then leans in and brushes her lips against his, before pulling back and whispering her response. "You're my best friend."

He smiles a smile so bright that she thinks he could light up a city with it, before pulling her back in, this time deepening the kiss, filling it with all of his love for her.

"You, Katherine Beckett, are my best friend as well." He whispers to her between kisses.

—

A/N: This doesn't mention past occasions of him helping her through her nightmares, so I was thinking that this could be the start to a series of one shots based around that idea… let me know what you think?