This started as a drabble on tumblr (=the first 350 words of this piece) but then I was hooked and decided to expand it to full length.

AU insert for episode 4x20, 'The Limey' and all you need to remember is that gorgeous black dress and a forlorn-looking Beckett and that desperate, desolate longing in Castle's eyes.

Cynosure

His touch is more tender than she would've expected. Almost disbelieving as his palm skates across the curve of her breast, a stark contrast to the sharp intensity of his tongue in her mouth, deep and searching, seeking her with a desperation she can taste, feel down into her fingertips and toes. Heat flares through her, the blood roaring in her ears, pounding in her lips.

She covers his hand, squeezes so that his fingers dig into her flesh and she moans into his mouth as the sensation sharpens, shoots straight to her midsection, leaving her wet, aching, wanting.

"You're mine," he growls, his voice raw and possessive, squeezing her again while his leg pushes between her legs.

She clamps around him, shivers in his arms as she rides his thigh, seeking the hard pressure against her middle, the bright, intense flares that shoot through her, spiraling her higher and higher, so fast, unstoppable and "yessss," she hisses, can't help it, her head falling back, fingers digging into the flesh of his shoulder. She is his, she's been his for so long. She thought she had lost him and it hurt more than she could've ever imagined.

His mouth attaches to her jaw, lips and tongue and teeth finding a path down the column of her throat.

"Mine," he repeats, softer this time, quieter, more like a prayer laid at the altar of her skin. There's an ache there that's undeniable, a desperate plea that speaks of the pain he endured, the hurt he felt, the fear of losing her and it's eye-opening, just how much he wants her, needs her.

She hooks her thigh over his hip, presses herself closer, so close that there's no space left between them, close enough that he can feel the race of her heartbeat, the chopped rhythm of her breathing. Wraps her hands around his face, palms cradled to his jaw, until he looks at her, eyes heavy-lidded, darkened with arousal, silent yearning drawn into every line of his face.

"I'm yours."

He surges for her, can't help it, soaking her confession into his mouth, tasting its truth against his tongue as he curls it against hers, seeking everything she is because he still can't believe that Kate is in his arms, lithe and warm and so willing. She gasps, opens for him and she tastes so good, like the spice of the drink she must've had, like the elusive cherries that he's been chasing in his dreams and with his heart for years. Like everything he's ever wanted and he has to swallow down the tears that rise through him, clog his throat.

"Kate..." He sobs into her mouth because he thought he'd lost her; worse, he thought he'd never had her and the pain had been unbearable, an agony that tore through him, made him feel weak, and lost, his need for her clawing at him like his heart was being torn from his chest, like his skin was shredded off his flesh.

And now she's here, writhing with a hunger that sets him on fire, kissing him like it's the only thing she needs and he can't get enough, just can't get enough. He needs to feel her, taste and touch, needs to soak her inside himself until they become one and she is a part of him, irrevocable and eternal. He scrabbles at her dress, fingers plucking at the material, trying to draw it up up up; too much fabric between them when he needs her skin and her warmth and her softness. At last he's got the black, slim skirt hiked up to her hips, his fingers gripping her smooth thighs so that he can lift her to him.

He's almost startled by her ferocity when her legs clamp closed around him, her warmth settling against his pelvis where he's hard and aching for her. He pushes her against the wall and she groans, back and neck arching invitingly. His lips find her collarbone, nip and tease and taste her delectable skin while his fingers delve beneath the cups of the dress, curl against her flesh, fingertips teasing the hardened nipple and oh, she's so incredibly soft, and the sounds falling from her lips scorch him from the inside out, his body on fire.

She's not sure how they even got here; one moment he'd looked at her with such disappointment and desolation in his eyes that she could hardly breathe, and the next he'd dragged her into his arms, pushed his mouth to hers before she knew what was happening, his grip tight around her. It was hard and possessive at first, not at all what she'd expected but all her sadness poured from her, flavored their kiss when she opened herself to his intrusion because she had missed him so much, couldn't help but flare with yearning that she had suppressed for so long. And he felt it; he'd always known her better than anyone else before. He melted into her, his lips tender as he caressed hers, his tongue sliding deep, desperately seeking. She doesn't care how it happened or why, she just wants it to never end.

She's writhing in his arms, almost helpless against the onslaught of sensations but she's never felt safer or more wanted before. His fingers are clever as he teases her and sensations lance into her core, deep and low, all of her weeping for more. She's clawing at his chest, frantic for his skin, his touch, for his fingers and his mouth and his thickness within her. She hears herself moan when he pinches her nipple, the sound almost foreign to her ears and she grabs his wrist, pushes him low, lower, tries to wedge his hand between her pelvis and his thigh because she needs him to feel how she's yearning for him, how much she wants him too. Her knuckles brush his length and he groans her name, his muscles rippling, hips surging forward. Heat rushes through her, her cheeks flushed, the blood pounding through her veins.

"Touch me," she sobs, not above begging but the angle is all wrong so she slides off his hips and turns around, hands and forehead pressed to the cool wall and her rear pushed back into him. He wastes no time, immediately dives his fingers beneath the lace of her panties, twin moans reverberating through them as he slides through her wetness, finally, finally. She sobs at the onslaught of sensations as he circles her nerves, curls one finger inside, out, back in; sends her spiraling at lightning speed.

Oh god she feels good, so incredibly good, hot and supple and everything that is amazing in the world, her body tightly gripping his fingers, fluttering around him. He doubles his efforts, slides in and out, can't get enough of her; he adds pressure, circles, brushes, teases her while his other hand tugs down her neckline and squeezes her breast. She cries out, throws her head back against his shoulder as she wiggles and arches and surges against him, and he almost can't take any more. He's ached, yearned for her, loved her for so long that the reality is overwhelming, far surpasses anything he's experienced before because she's extraordinary, everything about her, her strength and her passion, that fiery spark and the subtle shyness beneath. And then she's arching back, quivering in his arms, her whole body wracked with the shock of her release, keening sounds falling from her mouth that he wants to taste against his lips.

"Castle..." She's breathless, her slender body boneless in his embrace, her voice raw as she sighs his name. "Rick." Her hand reaches behind her, fingers trailing between them, teasing his length through his pants where he is straining against the fabric while she's trying to work down his zipper.

"No," he growls, whirling her around. Her eyes widen but he leaves her no time for concern, just hikes her knee high over his hip, sandwiching her between the wall at her back and his straining body. "I want to see you."

Her teeth graze her bottom lip, catching her own shy smile and a fresh bout of arousal rolls through him like a shockwave, his body twitching. She's so beautiful, absolutely breathtaking and he can't stop staring at her, take in every subtle move, each expressions that plays across her face. She smooths her fingertips down the row of buttons on his shirt, popping them one by one, drawing lazy circles across his chest, his stomach, her touch so light and tender that his skin tingles, sensations sparking through his blood. Until she reaches the button of his pants, slides down the zipper, her fingers brushing against him and he can't take it any longer, He lets his pants and boxers drop before he swiftly hikes her up against him.

She shivers, her legs folding around him once more and he feels her against him, hot and slick, a lifetime waiting for him in her arms. He cradles his palm to her cheek, his thumb painting her cheekbone until her eyes flutter open.

"There's no turning back from this," he implores, his heart pounding. "I can't..."

"Shhhh." Her fingers slide though his hair, cradle his neck as she pulls herself closer, her mouth brushing the shell of his ear.

"I want to feel you..." She whispers, nipping at his earlobe, "inside of me." He groans, his hips thrusting against hers, all of him flaring with need, aching for just that.

"I'm yours, Rick. I want to be yours." Her lips dance across his jaw, brush his lips as she sighs sweet promises that starkly contrast the tight, dirty rhythm of her pelvis when she rolls her hips against his.

"I just want you."

And then he's inside of her, filling her to perfection, thick and hot and deep and the world around her ceases to exist. She can barely breathe, can only cling to him, her fingers digging into his bicep, his neck, her forehead dropping to his shoulder.

His hands gripped beneath her thighs he thrusts, hard and deep and she keens out, her back arching, her head thumping against the wall behind her. He swallows her groan with his mouth, his tongue gliding inside. Their kisses getting sloppy as he speeds up, surging deeper, in and out, in and out, a rapid, pounding rhythm that consumes her, fire licking at her insides. Her body contracts, squeezing him and god, this is what she needed- he is all she needed, wanted so desperately, him, just him.

She's clinging to him as she flies apart; it's sudden, hard; a tidal wave that crashes over her, sweeps her away. Bright white light flares behind her eyelids and she cries out as her whole body clamps down, jolts again and again, muscles quivering and back arched and her fingers clenched into his flesh. His body tenses; she can sense him teeter on the razor-sharp edge of oblivion and it's the most arousing, most incredible thing she's ever felt. Her body quakes, squeezing around him and he breaks apart with a raw groan, mouth and teeth against her neck.

"I love you, Kate. I love you." He gasps the words to her skin with every rough jolt of his body around her, within her and the sheer joy sends her spiraling all over again, delicious frissons of aftershocks consuming her because he loves her- he loves her.

They sink to the floor in a breathless heap of tangled limbs and disarrayed clothing, her arms and legs still bonelessly draped around him. She listens to his heart pounding in his chest, his rapid breathing as his lungs seek oxygen, feels his muscles still shiver beneath her. His fingertips tremble up and down her spine in a languid melody and she curls closer to him.

"Did you mean it?' She whispers into the sudden silence, shocked by the wave of insecurity swamping over her because she's been clinging to it, has wanted to believe it for so long and yet she's always been scared of the answer.

"Every word." It's quiet, matter-of-fact and her heart thunders in her chest.

"What happened?" There's no accusation in her question, just confusion lingering from the past weeks when she had felt the distance he'd been building between them, and the creeping suspicion that he was preparing to leave her and not come back. The fear had been like claws that hooked into her heart, sharp and ice-cold.

He sighs and it feels like resignation, yet his arms tighten around her back, dragging her closer instead. "Thought you didn't lo... Didn't want this."

She lifts her head to face him, waits until his eyes meet hers, so clear and blue and beautiful. Suddenly she's overwhelmed by the way he looks at her, breathless with it, her heartbeat leaping into her throat. Concern lingers in the swirl of ocean-blue and yet there's such warmth, so much love there, deep and endless- and she dives in.

"Castle..." Her fingers tremble as she caresses his jaw, her eyes holding his.

"I'm in love with you."

- fin -