The banging had made its way into his dreams before it had managed to wake him, and now he made his way, barefoot and unsteady down the staircase, rubbing at his eyes in an attempt to open them so he could see the person who was about to die painfully for disturbing him.

"Martha? Alexis?"

In his sleep ridden state Castle barely made out that the two words were in fact questions as he opened to door to a smiling, sparkly eyed and slightly wobbly Kate Beckett

"Not here..." Hmm, that had come out slightly sharper than he'd meant it to, but the damn woman in front of him had just roused him from the deepest sleep, and she seemed so cheerful about it.

Castle stood aside and gestured generally for her to enter, allowing himself the pleasure of her brushing past him to wake him fully, before suspicion and curiosity caught hold. He watched as she made her way straight to his kitchen, grabbed a water bottle out of his fridge and downed half in quick, long swallows.

"Coffee Castle?"

"Again with the blasted questions woman." Castle caught himself, realising just how ill-tempered he sounded, looking at the clock he knew why, 12:45, a time for all good cop-saving-writers to be tucked up safely in bed. "Sorry, yes.. coffee I'll make some."

His eyes narrowed as he realised that Beckett had ignored his grumpiness and started on the coffee before he had even answered her.

He stepped towards her, deciding to let this play out, late night visits were new, but she'd let him know what was wrong when she was ready. Castle watched as she expertly manoeuvred herself around his kitchen, gently humming to herself as she produced two steaming mugs of coffee, accepting the mug as she handed it over Castle tried to ignore the feel of her fingers sliding against his, tried to dismiss it as an accident.

Looking up as he took a mouthful of the coffee he was startled to see a glint in the eyes of the woman stood over the counter from him, he'd seen that look before in her eyes, earlier in the evening before they had saved Ryan and Esposito. He may have started the plan into action, but with that look she had finished it, and almost finished him in the process Castle swallowed hard and hedged his bets with his next statement whist Beckett worked her way around the counter to stand in front of him.

"Mother and Alexis have gone to the Hamptons for the weekend, thought I needed the time to write."

"Hmm" She continued to watch him, and he tried to pretend he couldn't see as her eyes flicked down his chest and up towards his lips. "Ever been told you're kinda cute in your PJ's Rick."

There was a playfulness in her voice that he wasn't used to hearing from her, especially after a long day like the one they had just had, . He took another gulp of the hot liquid in his hand just for something to do before he answered her.

"I'm not sure what I like best about that statement, Detective Beckett." Castle grinned at her, watching as she almost blushed under his gaze. "The fact that you noticed or that you used my first name."

He continued to smile until he suddenly realised that her hands were empty of the mug they had been holding and were inexplicably making their way under his tee-shirt, leaving a trail of fire where her fingers touched him. Spilling his coffee in his haste, Castle caught her wrists in his hands, pulling them away from his skin and held them together between their bodies.

"Kate! What the hell?..." A realisation hit him, and he mentally kicked himself for something he should have noticed before. "Have you been drinking?" The concern he had been holding in since she had arrived poured out in that one sentence.

Slowly she nodded but didn't allow her eyes to leave his, she stared intently at him, trying to convey something that he just wasn't getting. Castle pulled her towards him, wrapping his arms around her as she followed the action with her own arms, he rested his chin on the top of her head, concern, fear and interest mixed in equal measures as he gently stroked the small of her back. Beckett slowly relaxed into him allowing him to tighten his hold on her briefly before pulling back, catching her chin in his hand he placed a chaste kiss on her forehead before taking her hand and leading her towards his sofa.

Indicating that she should sit Castle retrieved their now lukewarm beverages and joined her.

"Tell me?" It wasn't so much a question as a request, one she was free to refuse, though he knew from experience that Kate Beckett wasn't one to walk away because the answer was hard.

The silence that followed wasn't uncomfortable, but thoughtful as she struggled to find the words, a couple of false starts and stumbled words and Castle knew she was conflicted. Leaping of the sofa with sudden inspiration he grabbed her hand and dragged her towards his study.

"Come with me...something I need to..."

He almost stopped at the small laugh that escaped Beckett's throat. "No choice Writer Boy, not with a grip like that."

Releasing her so he could rummage on his desk for a specific piece of paper he continued using his peripheral vision to keep an eye on her, watching her watch him with a strange,almost sad smile on her face.

Triumphantly he slapped his palm down on a sheet as it tried to slide off his desk, making her jump in the process and pulling her attention to what he wanted to show her.

"Come here." He held out his hand for her to take as she moved closer, he moved the sheet into her line of vision. "Read this."

"KB. Always, I promise. RC"

Castle watched as Beckett absorbed what the writing on the sheet said, knowing that when she turned towards him she understood.

"It's the dedication for the new Nikki Heat novel, and I mean it, no matter what." He saw the tears starting to form at the corners of her eyes and knew that she was ready to talk.