A/N: Another one-shot photo prompt set during 4x20: "The Limey," after Castle sees Kate in *that* dress. Photo in question is the cover art for this story and can also be found on my Twitter feed.

May I Have This Dance

British Consulate General, 845 3rd Ave, New York - 8.56PM

He caught sight of her from the hallway, a dark shadow glimpsed through a spectacular display of floristry. Heart hammering, his endgame clear in his mind, though his plan was rushed and sketchy, he found her. He was under-prepared, undeniably so. This was the kind of thing he knew Beckett hated. In fact, it couldn't get much worse: here, in a roomful of well-dressed, rich and powerful strangers. But he'd already waited long enough, bit his tongue, bided his own damn time. If tonight was anything to go by - suave Colin Hunt leaving the precinct with Beckett on his arm - things were getting away from him, fast. And if he didn't act soon, he'd lose his nerve or worse: he'd lose everything he'd been counting on for months.

Months of dreaming these small-time dreams, hoarded and counted, over and over; like the coins of a miser. Creative dramas played out in the secret recesses of his mind, anywhere that he cared - in bed, by her desk or the back of a cab. He would access them as a treat, as a comfort or a salve to his loneliness. Libidinous dreams of flesh and touching, of breathless, whispered words of love and lust. And chaste, romantic fantasies of breakfast in bed or walks in the park, dinners by candlelight and movie theaters in the dark. Always just the two of them: spending time and simply holding hands. And her kisses: his mouth on hers, her lips on his, claiming, needing him. This was the flame that had sustained him during his lengthy wait for these coveted delights. Today that flame had guttered. He would not let it go out.

And that meant tonight was the night. He decided to give himself no choice in the matter, and to hell with the consequences and the doubts he'd begun to harbor in the last few weeks. He'd be victorious or he would lose. Either way, he couldn't regret not having taken matters in hand for once.

So he caught just a glimpse from the hallway. Like a deer in a stand of shadowy trees or a will-o'-the-wisp, he spied her. Moving too fast in his search, he had to backtrack to find her again, a truly extraordinary creature tonight. Her hair was up, her elegant neck and throat exposed, shoulders and décolletage bared by a daring, black gown that had stolen his breath away at first sight. It was an image of perfection that wouldn't leave him, and had, in fact, led him to this place. His blag at the door had been a Tony Award winning feat in itself. His mother would be proud. His partner…yeah, not so much.

She was wearing a cocktail ring on her left hand. A huge sparkler that would have looked quite at home on the finger of a Kardashian, were it real. The gemstone demanded Castle's attention from plain across the busy room, since it resembled an engagement ring and his poor heart and racing mind were on high alert for trouble of that kind tonight. Like a beacon in the dark, he caught sight of her through the throng of designer-clad bodies weaving here and there, faceless people swaying to music of polite orchestration, and he sailed towards her. His homing signal, his safe-haven, though she would not believe that yet.

"Castle, what are you doing here?" Kate hissed, startled, having no option but to disengage from her current partner and accept the open welcome of his arms, lest she draw attention to herself by refusing his request to dance and end up causing a fuss that would expose them both.

She felt his arms slide around her, gathering her up, gathering her to him, closer than ever before. His cologne filled her nostrils and his hands seemed to be everywhere at once, claiming her if she wasn't mistaken. They were crossing a line, and it confused her: this sudden impulsive drive of his, here in a public place, and while she was on the job no less. He had her trapped by convention, by social mores and manners and the fact of not wanting to make a scene. His behavior angered her on some level. The level that sought to maintain control, and yet it intrigued her on that other plane; the plane that needed to let loose, since she knew this could never be her: the one brave enough to make such bold, declarative moves.

Her eyes slammed shut and she shivered when her body made full contact with his. He had been home to change since she left the precinct. He now wore a crisp white shirt, open at the neck, and a dark suit that perfectly complimented her dress. Fine black wool, maybe silk or even vicuña, the cut was expensive, well tailored for the broadness of his frame, the bulk of his muscles and his height. They made an arresting couple, of that Kate was well aware, even without the stares and the heads they turned as they began to move around the room.

Heat radiated from the base of his throat, from inside his open collar. His voice was a low gravel pit of need and emotional rawness when he whispered in her ear, spilling secrets left and right without any warning. "I saw you tonight in that dress at the Twelfth and I couldn't help myself. I was so jealous, goddammit, Kate," he cursed, tightening his grip on her body, even as he shuddered at his own desperate confession. His breathing was shallow, breath hot on her neck, both minty and laced with a hint of cinnamon.

Panic surged through Kate as she recognized what was most likely coming next - a showdown that had been building for months. "Don't. Castle, please don't do this here?" she begged, and he turned her away from prying eyes, spinning them off to a quieter corner of the room as a meager concession.

Because he had to do this now or lose out. He couldn't live with not trying. "I can't stand by anymore, Kate. Just…just sit on the sidelines and say nothing."

"We can talk. I promise," she coaxed, hoping that he'd stop before it was too late, before they were exposed to one another, with no going back and not a shred of anything left to hide behind.

"When you were shot…"

Kate closed her eyes on a whimper, resting her mouth on the back of her own hand, where it clasped his shoulder, to prevent herself from begging him to stop. Deep down she knew that she needed to hear this as much as he needed to say it, but the concept still terrified her. What if it failed? What if he hated what he saw? What they had now was still better than the alternative - nothing - surely?

Castle ignored this tiny sound of distress and carried on. "When you were shot, I was more scared than I've ever been. More scared than the day Alexis was born and I looked into Meredith's eyes and realized I'd be raising my little girl alone. I had fallen in love with you. A long time ago. But I knew you weren't ready…didn't know if you ever would be. So I waited. Hoping."

The words kept pouring out, ceaselessly. He turned her around the room again, the music more or less an irrelevance, and Kate found herself holding on tighter just to stay upright. "And then you were dying. Right in front of me, you were dying, Kate. And I couldn't hold it in any longer. You had to know. You had to hear me tell you that I loved you in case that was all the time there was left for us."

"Castle," she whispered faintly, her lips so close to his ear that she felt him stiffen when she brushed the warm skin with her mouth by accident. The question of who was holding up whom was now as blurred at the vision in Kate's eyes, when tears swelled the room to disturbing proportions as they spun past the orchestra one more time.

"Please. You need to hear this. When I saw you tonight, with him—"

"This is work," she protested, drawing him closer without even thinking about how her gesture might look to him, driven by an urge to comfort and console.

"Doesn't matter. I saw you in that dress and I had to come find you, had to tell you—"

"Is this man bothering you, Miss?" A security guard in a dark suit tapped Kate on the shoulder.

"N…no," she stammered, quickly waving the guard away to minimize any fuss. "Everything's fine."

This threat only seemed to amp up Castle's urgency. He caught her gaze and held it, fiercely. "Kate, listen to me. I know we had some vague discussion after my book signing, and I thought that meant that we were…" He shrugged and faintly shook his head. "Waiting or something. But in case I was wrong or I wasn't clear or you really didn't hear me that day at the cemetery. I'm in love with you. Okay? I love you, Kate. And I know you're working tonight and I don't want to come across as some jealous jerk. But all we are right now is partners. No closer than Ryan and Esposito. And…and I want us to be more than that. Understand? Now who lied to whom is irrelevant as of this moment. I don't even care why anymore. I just want you to know that I love you, Kate. I mean I want you like you wouldn't believe and—"

"Shhh!" Kate smiled around a watery laugh, burying her flaming face in his neck. "I heard you the first time. I think the whole room did."

"Did I blow your cover?" he whispered weakly, offering her an apologetic grin, as he glanced over her shoulder to take in the room for the first time since he set eyes on her tonight.

She rested her cheek against his and they swayed a little longer to keep up the pretense that they were merely two people dancing, and not star-crossed lovers trying to beat the odds. "Tonight's a bust anyway. I don't think our guy's even here. Just let me talk to Hunt and we can leave."

"No. No, you should stay. Do your job. See it through. Gates doesn't need another excuse to can my ass. Call me later?" he asked hopefully, dropping his hands from her back to rest on her hips, lightly holding her to him.

Kate bit her lip. "I wish I could leave with you right now," she whispered, tears shining on her lashes.

"Then that's all I need to hear."

She looked into his eyes. "I'm so sorry about…"

"Shhh." He stroked her cheek. "Water under the bridge."

"Hunt's coming over," she hissed quickly, so as not to look too unprofessional. "You should go," she told him, swiping at the tears now drying on her cheeks.

"Leaving," he nodded. "I'll speak to you later."

As he stepped away from her, Kate grabbed hold of his hand and impulsively reeled him back in. Dragging him into a darkened corner, she pressed her forehead against his and then smudged a fiercely passionate kiss against his mouth. "I love you too," she whispered breathlessly, cupping his cheeks with her hands, forehead once more melded with his. "Wait up for me?" she asked, her chest heaving in her strapless gown.

Castle's face was a picture of slack-jawed astonishment. How differently the day was ending compared to how it had begun, and all because he'd taken a chance. "Of course. Come right over. Don't stop to change, okay?" he begged, allowing himself one final, carnal sweep of her body in that clinging black dress.

Kate smiled as she let go of his hand. "Straight over," she nodded, eyes full of understanding, love and a promise she wouldn't break for once.

And then, like a shadow, he melted away.

Thank you for reading.