This starts in season 4, during "Demons." Multi chapter, but not too long, maybe five. Big chunks of dialogue from the show used in this intro. This is so much fluff it's practically rotting my teeth, so I had to get it out.

.

.

Castle has the upper hand for once.

.

.

Two Can Play

.

.

When Castle came over that night Beckett was already feeling unusually loose. A warm bath and a few glasses of wine and the way her mind kept wandering to the deeply affectionate amusement Castle had been pulling from her while they were working this ghost case, an affection she was more and more willing to revel in instead of constantly denying, had left her feeling more relaxed than she had all year.

Apparition American, she thought, grinning widely before taking another sip of wine. It was a Pinot she'd only just discovered, and it had a way of making her giddy with delight, especially the Castle induced variety. While she was alone in her own apartment she didn't need to press her lips together to hide her amusement at his playful turn of phrase. And his theories. And his ghost house murder mystery board. And the way he'd bought her two coffees, even if he'd managed to drink them both himself before she arrived.

She sighed and rolled her eyes at herself as she sank down onto her couch, still smiling while she twisted her mostly dried hair into a loose braid. Allowing herself the luxury of fantasizing, she rested her head against the back of the couch and closed her eyes, revisiting the way Castle had looked today, the low timber of his voice while he was explaining his theory with wide eyes and gesticulating hands. She was just imagining what it might feel like to have those hands trailing down her arms or tugging lightly at her hair, the tip of her tongue caught between her teeth, when there was a loud knock at her door.

"Laird's Lug!" Castle said triumphantly when she opened the door.

Beckett wrapped her shrug more tightly around herself as she followed him into her apartment, as if that could prevent him from seeing the flush she was feeling, the combination of the wine and the fantasy and his unexpected presence. He was still talking about Scotland and hidden passages, so she leaned her head forward and really tried to listen. Really she did. But try as she might, she found herself wondering more about whether or not his plaid shirt was as soft to the touch as she imagined than whether or not the Maclaren house had a hidden alcove.

"It explains everything," Castle declared, his chest puffed out with pride.

He carried on with the story, but again her mind was still wandering, her relaxed muscles and the wine fogging her senses leading her down potentially dangerous paths. She was imagining the tickle of the brush of his lips at her ear and the way his voice would vibrate if he were whispering his story to her instead of standing across the room when she realized he'd stopped speaking.

"We'll go first thing in the morning, see what we come up with," she agreed, remaining purposefully vague to cover the fact that she'd only been half-listening. The details of his story remained elusive.

Castle paused, mouth half open as if to speak, and shifted his weight.

"You want to go now?" she asked.

"Well, unless, of course, you're afraid," he challenged, his expression so smug she could kiss it off of him.

"Yeah right," she huffed. Please. Afraid? No way.

"No I get it, it is a haunted house."

"I'm not scared, Castle," she fired back.

"No, no you're right," he consented, "the demon has tasted fresh blood, his thirst may not be slaked with just one victim."

"Ok..."

"If you're not scared just say it," he pushed.

"No." The answer was firm despite the pull of a smile at her lips.

"Come on, you know you want to," he argued.

"I don't want to say it Castle."

"For me, please."

It was the please that did her in, and the knowledge that this silly conversation and a night spent poking around the potentially haunted house would make him so happy. She complied with a barely suppressed grin. "I aint afraid of no ghosts."

She gave in, and was ready to go to the Maclaren house with him, but when she rose to head toward the door she felt the heaviness of the wine bend her balance enough that she had to press her hand to his shoulder to steady herself and prevent knocking in to him completely.

"Woah," he said, catching her hand and helping her regain her balance.

Beckett laughed lightly, averting her eyes while a little more red seeping into the blush of her cheeks. "Oh, Castle, we really can't go tonight."

He furrowed his brow at her, glanced at the hand still lightly gripping his shoulder, and dramatically pointed to the half empty bottle of wine on the counter. "Beckett," he cried, "you're drunk!"

"I'm not drunk, Castle," she argued, rolling her eyes. "But I'm also not fit to be brandishing my weapon." When he raised his eyebrows as if to say Isn't that the same thing? she headed him off by turning the hand still in his grasp, catching his wrist between her fingers, and brazenly pulling him back toward the kitchen. "Besides, wouldn't you rather stay here and have a drink?"

She tossed him a look that was both a challenge and an invitation. Castle was so quick to agree that his answers all fell over each other. "Yes... tomorrow... of course... can wait... would rather... what are you drinking?"

Her warm laughter was his only answer, and she pressed the mostly full glass she'd been drinking from into his hands, meeting his eyes with a new kind of intention in her own, her fingers lingering purposefully against his. While Castle contemplated the fact that her lips had just been touching this glass, she poured a second helping for herself. Shrugging out of her wrap, when had it gotten so warm in here anyway, she slid back onto a stool and gestured to the closest one for him, hooking her toe around it to draw it a bit closer before he sat.

"So, do you like it?" she asked, still smiling at him like she had some kind of a secret.

"Yeah," Castle answered, nodding, looking intently at her. He realized too late that she meant the wine, and hurriedly took a sip. "It's great."

She hummed. "It's a new favorite." She was speaking softly, glancing up at him through lowered lashes as she drank again.

"New is good," he said, feeling a little dopey with the change of pace. Beckett had never looked at him so openly, had never sat so closely to him without a reason, had never invited him to drinks in her apartment. New is really good, he thought. He smiled and leaned forward, resting one elbow on the counter and letting the opposite hand dangle dangerously close to where her knees were almost brushing his.

"Tell me more about your theory," she said when the silence had gone on a little too long.

"Let's not talk about the case," he replied absently, too caught up in the way his rebel fingers were brushing against the warm fabric at her knees to remember the theories that had seemed so important just minutes ago.

Beckett murmured something he didn't quite catch and shifted, moving one foot to rest on the bars of his stool, and his hand slid naturally around to the back of her knee. He squeezed lightly, his fingers dipping into the muscled calf, and she sighed. It wasn't until she caught his free hand in hers, linking their fingers on the countertop, that he looked back up at her. He caught his breath at the raw want in her dark eyes, the way she had caught the smile of her bottom lip between her teeth, and the subtle way her knee shifted more fully into his palm.

Beckett wanted him.

She didn't just want him in some vague when I'm ready way and not in a when my walls come down way, she wanted him here, and now. From where he was sitting, he couldn't see any walls at all. For the first time in their entire relationship, Castle felt with utter certainty that he was not alone in his desires. So he finally allowed himself to act on them.

He used the hand at her knee to tug her a little closer and half stood so she wouldn't fall off of her stool. He released his hold and slid his hand around her waist, squeezing where the fingers of their other hands were still entwined, and he kissed her.

.

Oh. Oh, Castle was kissing her, and he wasn't holding back. His lips were sliding warmly against hers, the hand at her waist was somehow beneath her shirt and the fingers were pressing lightly into her skin caused her to arch her back sharply until she was holding on to his hand to keep the dizzying sensation in check. Beckett parted her lips at the first touch of his tongue and gave herself over to him, allowing herself to revel in finally knowing the feel of him like this.

She sucked in a breath when he nipped at her lower lip and laughed quietly when he did it again with a grin. The laugh became a moan when he kissed her fully once more, slicking his tongue heavily against hers. Then suddenly, he was pulling back. He removed his hand from under her shirt, tugging it back into place as he went, kissed her lips lightly one more time, and then moved away toward the door.

"Castle?" She asked dazedly, the fingers of one hand pressed against her swollen lips. He grinned, and when he answered his voice was delicious with roughness and want.

"Until tomorrow, Kate. And I promise I won't drink your coffee this time," he said. "Sweet dreams." And then he was gone.

Beckett blinked.

Wait. What?

What just happened?