spoilers: Chelsea Cain's Archie Sheridan/Gretchen Lowell novels.

Castle pulls her across the bar, seeking out a place where they can have a moment to themselves. A moment to process whatever the hell it was that just happened. Spotting an unoccupied dark corner, he aims them for it, brushing quickly past the party attendants. He can hear Kate muttering pleasantries behind him and knows he's being a bad guest of honor but he doesn't care because right now he just needs a damn moment.

Reaching his destination, he turns and sags against the wall, her hand still clasped tightly in his. Kate steps into him, her free hand rising to rest on his chest, fingers playing with the collar of his shirt.

"You okay? It wasn't that -"

"You were seriously going to elope with some douche named Steel and you won't even let me mention the word marriage?"

"Steel was just his stage name," she sighs. "His actual name was Steven."

"Because that makes all the difference."

"Castle, listen to me." The hand on his chest moves up to this face and her fingers are cold against his flushed cheek. His free hand gravitates to her waist, his thumb drawing tight circles over her silk covered stomach. "I was seventeen and very stupid. I had no idea what marriage actually meant. I tried to elope in Atlantic City, for christ's sake."

"I've suggested that," he mutters and she pats him on the cheek, a smile pulling at her lips.

"We've been dating for less than a year and while I very much intend on having a future with you I really like where we are now." She leans in and brushes a kiss across the corner of his mouth. Her lips are soft and taste like sugar and alcohol and god he loves her. "There's no need to rush, Rick. We'll get there."

Castle drops her hand and wraps his fingers around the base of her neck, pulling her in for a searing kiss. She comes willingly, her lips parted and tongue sliding against his. He groans into her mouth, the hand on her waist slipping around to splay over the small of her back and pulling her hips up against his. Her fingers slip into his hair, nails scraping over his scalp, her body pressing against hotly into his.

"You two are disgusting."

Kate pulls her lips from his with a pop and looks over her shoulder at where Lanie is propped up against the bar, a hot pink cocktail dangling from the tips of her fingers. Laughing she turns back to him and withdraws her fingers from his hair, running them lightly down over his neck and chest. Leaning in close, she holds her lips next to his ear, her breath hot and heavy against his cheek.

"By the way, my bike isn't the only proof you have of my wild phase." She nips at his earlobe and it takes every last shred of his self control not to spin around and pin her to the wall. "You've seen my tattoo." He feels her tongue run along the shell of his ear, her fingers curling into his chest. "Repeatedly."

Kate spins away and leaves him up against the wall, dumbstruck and gasping for air. He loves that she has this kind of effect on him, even after all this time. The way she loves him, with her whole heart and mind and body, astounds him on a daily basis. He watches as she saunters away, tossing a wave at Lanie, her hips swinging exaggeratedly. Yeah, she's totally doing that on purpose.

"I see neither of you have ever heard of subtlety," Lanie muses.

Castle looks at her, mouth widening in a smile. He sidles up to the bar and leans against the counter, body turned toward her. He can still taste Kate on his lips, electric lemon and the perfect amount of vodka.

"I was subtle for four years."

"Richard Castle, if you think you were even remotely close to subtle you might want to get that dictionary of yours checked."

He locates Kate across the room talking to Esposito, drink clenched in her hand. He can hear her laugh from here, vibrant and happy and so incredibly different than the woman he met five years ago. "Okay, I was never quite subtle, but can you blame me? Look at her."

"I think you do enough looking for the rest of us," Lanie smirks, accepting a fresh drink from the bartender.

"Can I get a scotch, Brian?" Lanie cocks an eyebrow at him, lips pursed. "What?"

"We went to a lot of trouble to concoct these bright-ass cocktails, Castle." She waives her drink at him, the crayola red liquid sloshing perilously close to the rim.

"I know. And I appreciate it but I can only handle so many sweet drinks." He nods to Brian and takes the tumbler of scotch off the bar, holding his bent arm out for Lanie. She winds her arm through his and they start to move, making their way across the bar to where Kate and Esposito are holding court with Ryan and Jenny. "You helped Kate with the party?"

"Mm-hm."

"Does that include helping her with my present?"

"Mm-hm."

At her tone, Castle turns to look at her and sees her lips pulled up into a wicked smile, her dark eyes dancing with some secret he finds himself desperate to know.

"Tell me what it is, Lanie. Please," he begs, putting on his best wounded little boy face. "She won't give me even the tiniest of hints and I'm dying here. I mean, what if I don't like it and I'm not properly prepared to hide my reaction? You don't want me to hurt her feelings and make her doubt her gift giving abilities do you?"

"Trust me, there's no need to worry about that. You will definitely be a fan of this present."

"You're not going to tell me either?"

"Not even a little."

"Evil."

"Who's evil, bro?"

Esposito slides out of the booth and waves his arm, letting Lanie slip in next to Jenny. Castle sits down next to Kate, her bare leg pressed tightly against his. The round booth is roomy and maybe he doesn't need to sit exactly this close to her but she's not moving away so he's not going to complain. Kate crosses her legs toward him under the table and the toe of her high heel brushes over his shin. She smiles into her glass as he drops his hand to curl around her outer thigh and runs his fingers up and down the smooth plane of exposed skin.

"Lanie," he answers Esposito, shooting the woman in question a dirty look as she smirks at him. "She knows what Beckett got me for my birthday but won't share."

Jenny titters from the rounded corner of the booth and his eyes fly to her. Her face is flushed and her eyes are little glassy from the cocktails. A weak link, perhaps.

"You know too, Jenny?"

"Yes," she giggles, her cheeks flaming. "Kate told us about it a couple of months ago."

"Months?" He can see Kate grinning from the corner of his eye, her fingers playing with the thick stem of her glass. "You've been keeping this from me for months?"

"It took some pre-planning." She shrugs one shoulder and takes a sip of her drink, the corners of her eyes crinkling with her smile.

"Okay, now I have to know. Someone please tell me."

"You'll find out soon enough, Writer boy," Lanie says, listing a little into Esposito's side.

"Do you two know?" He waves his index finger between Ryan and Esposito, trying to gauge their level of sobriety. If he can just get one of them tipsy enough to let it slip...

"I don't know," Ryan offers, "and, judging by the look on my wife's face, I'm guessing I probably don't want to know."

Jenny swallows the rest of her drink, grinning widely. "I'm not saying a word."

"Come on, Jenny. It's me," Castle urges, turning on the charm. "If you tell me, I might be able to get you someone on your freebie five list. Ryan won't mind, right buddy?"

"I never got to sleep with Natalie Rhodes!"

"Honey, if I can sleep with Channing Tatum, you have my full permission to go find Natalie Rhodes and do whatever you need to do to her." Jenny turns to Castle, eyes wide. "So, Rick? Do you know him?"

Shit. She couldn't have wanted to sleep with Alex Conrad? A Yankee? The cast of some low budget B movie? He has to play this cool. She doesn't want Channing Tatum what with his abs of steel and gorgeous eyes and - oh. "Isn't he a little young for you, Jenny?"

Yeah, he's too young. Make her feel a little dirty. Like she's -

"I'd sleep with him," Kate chimes in.

Lanie makes a noise deep in the back of her throat. "Me too. That boy has an ass on him like-"

"Thanks, bro," Esposito grumbles. "Now I'm going to have to listen to this for the rest of the night."

"Don't worry about it, Espo," Kate teases. "Castle talks a big game but he doesn't know nearly as many people as he likes to think." She pats him on the leg, eyes filling with mirth. "Your birthday present is going to remain a surprise. Sorry, babe."

"Aw Esposito, our little Beckett is all grown up, calling her boyfriend babe," Ryan teases.

"Quiet down, honeymilk," Kate retaliates. Cutting her eyes at Esposito she continues, "And don't even start, sweet cheeks."

"You told her about that?" Esposito squawks, spinning to glare at Lanie.

Castle emits a sound, something between a squeal and a gasp, covering his mouth with his hand. "Best birthday ever!"

"I wouldn't get too excited, Castle. Beckett has some nicknames for you too."

Oh, does she now? Castle leans into her, the palm of his hand sliding over her thigh. She looks up at him, eyes filled with mirth and something else he can't quite figure out (it's not so much desire as it is, something. He's usually better at finding words than this). Her lips tilt until it's a full blown smile and she laughs with a gentle shrug of her shoulder. The old Kate Beckett would have been more embarrassed; this one - the one who has thrown him a party that is even up to Richard Castle standards and is letting him openly touch her in a room crowded with their friends and colleagues - doesn't seem to have a care in the world. He likes her this way, wants her this way forever.

"I look forward to hearing those later," he whispers into her hair and he can feel the way she shivers up against him despite the amount of bodies in here and warmer than usual ambient temperature. He keeps his hand on her leg; skin soft and warm beneath his fingertips as he looks around the room. There are still so many people he hasn't said hello to that she should. Paula, some of the publishers at Black Pawn, his poker crew, some other writers he's known for years. He spots a blonde in the corner, grabs Kate's hand. "Come with me for a second. There's someone I want you to meet."

Kate nods in agreement, sliding out of the booth alongside Castle. "Excuse us, we'll be back."

"Hey Castle," Ryan calls out, "is guitar hero still set up in that back room?"

"Yeah. I call next round! Come find me when Esposito kicks your ass."

"Thanks, man." Esposito grins, turning to Ryan. "Told you you didn't have a shot."

Kate's laughing as he pulls her along, her hand tightly squeezed between his. He weaves through a group of people, catching sight of his mother, Jim and Gates still at that table, still laughing and oh god there are stories Martha knows that no one should ever, ever find out about. Like things having to do with squids and Ferris wheels, alcohol and funnels, amusement park rides and Disney World jail. Yeah, he should probably tell Kate some of those things also. Just in case. Later. After his birthday present.

"Is it smaller than a bread box?" She lifts an eyebrow in question. "My present."

"Castle," and her voice is stern. Huh. That isn't good. "Keep asking me and you're not getting it."

"Fine," he grumbles. He stops at one of the booths in the back where the blonde now sits, nursing a drink like she's waiting for someone.

She glances up at their approach, her eyes lighting up. "Rick Castle. Happy birthday, old man."

"Careful, Chels," Castle laughs, hugging her, "you're only a year behind me." He turns to Kate, who seems almost - well, giddy. "Kate, this is Chelsea Cain. Chels, this is my girlfriend, Kate Beckett."

"No introduction needed," Kate says and there's a excited lilt to her words. "I'm a really big fan of your work."

Wait. She is? How did he not know this? She practically lives with him at this point and he's never seen her pick up one of Chelsea's books. Does she think he'd be jealous? Oh, he's so confused right now.

"Please, sit. I'm just waiting for my husband." Kate slides into the booth, Castle following, and really he doesn't think he's seen her this excited since the time she met Joe Torre, though she's thankfully a bit more composed this time. "I've heard so much about you from Rick," Chelsea mentions to Kate.

"Really?" Kate muses, tilting her head to look at Castle.

"What can I say? You're a very popular topic of conversation."

"I didn't even realize you two were friends, although I did wonder given Senator Castle in the first two books."

"She did not treat me kindly," Castle pouts.

"I could have been crueler. Made you one of Gretchen's victims."

"I have to tell you that I'm absolutely fascinated with the dynamic between Archie and Gretchen," Kate offers, her eyes sparking. "The first time I read it I was actually horrified that, even as a cop, I found myself rooting for Archie and Gretchen to be together, especially in Sweetheart. I really admire a writer who can get you that invested in a novel that your outlook changes during the period you're reading it. Can I ask where you got the idea from?"

Chelsea smiles, fingers twining around the stem of her wine glass. "I watch a lot of cop shows, I read a lot of mystery novels. You hear about Stockholm Syndrome and it's a concept that has always fascinated me. I thought what would happen if you worked on a case for ten years, developed feelings for someone only to find out they were the one you were hunting, the one who ends up torturing you until you're so close to death you're hoping it'll happen and soon. And from there Heartsick was born."

"Do you plan on writing more in the series?"

Castle lets himself zone out a little while they talk, only half paying attention to their conversation about the inherent problems of a love affair between a homicide detective and a serial killer. His eyes wander the bar, taking in the amount of people she's gotten to come here tonight. He's thrown parties in the past, but even he has to admit that none of them are as good as this. His wait staff is still wandering around, masks on, multi-colored drinks propped on trays and he slides his hand over her leg. It's been there most of the night in some way or another and he's cursing the fact that his damn office is a hole in the middle of the ground where people will obviously see them if they go, not to mention Kate is loud during sex when she's been drinking and - Shit. He has got to focus on this conversation.

"Castle is the same way," Kate says, and he snaps his attention back to the conversation at hand. Same way about what? "He's been hounding me about his present all night."

Chelsea laughs. "My husband does that to me every year."

He thinks about protesting; he does. But to fight Beckett with words has always been win or lose with him, depending how on her game she is. Tonight, she's really on her game. So, no. He needs something else, something she can't fight her way out of her, something that'll drive her absolutely insane, something that - oh. Yeah. That'll do.

He slides his hand over her thigh, listens to the slight, almost unnoticeable hitch in her speech pattern. His fingers are light as they prance over her skin, and her legs slide together because she knows him and he's certain she knows what he's about to do. He smiles at Chelsea, invested in the conversation again.

"So, Rick, how's the new Nikki Heat coming?"

Kate's legs widen a bit and he takes the moment to slide his fingers up and - Shit. He really should have expected it given the dress but the knowledge that she's been walking around all night - making small talk with his friends and colleagues, flirting with him shamelessly - without underwear makes his throat seize, his groin throb. His fingers still and he swallows and maybe this wasn't the best idea because he can already feel how wet she is and there has to be a bathroom they can sneak into or a dark corner or his Ferrari that's been stashed somewhere around here by the valet.

He gathers his thoughts - his answer is probably already about three seconds too late - and the pastes the smile back on. "It's good for the most part. Still trying to work through the case though."

"I hate when that happens. I couldn't figure out what I wanted for plot in the entire third book. Then of course I had Black Pawn on my ass and nothing gets me going like a little friendly threat from your publisher."

"I liked the third one. Better than the second one where you killed me."

Castle drags a finger through Kate's arousal, feels her tense, knows she's biting back a moan or a gasp. She feels so good, hot and tight and so fucking wet, as he pushes deeper inside of her, curling at the knuckle in a way that he knows drives her insane. Her features are schooled and he gives her credit for that, for having the presence of mind to hold herself together. He slides his thumb over her, narrowly missing her clit and she digs her nails into the wooden bench and yeah, she's going to kill him for this.

"You have to get over that, Rick," Chelsea teases. "Car accident is so much better than taking out your organs. It's fast, less painful."

He picks up his scotch and slides another finger inside of her. He feels her nails bite into his thigh and he tilts his head just enough so he can look at her. Her eyes are dark and hooded but her posture remains. He can see her pulse jumping under the pale skin of her neck, her chest expanding and falling with a rapidity that's just a little too quick to be natural. He wiggles his fingers inside of her, curls just enough that -

"What about you, Kate? Are you going to do publicity for the next Nikki Heat?"

Kate's eyes clear, snap back into the moment. He stills his motions, gives her a minute to catch her breath because he's not that evil. "I'm sorry, what?"

"Rick's mentioned that that Gina wants you to come to his next signing for publicity. Did you decide if you were going to go?"

He curls his finger with the flick of a wrist, smirking. He catches the shift in her face from the corner of his eye, recognizes the look she now wears. It's one he's seen many times, a mix of revenge and sheer determination, and fuck this has seriously backfired on him. Her hand covers his, her fingers slipping into the spaces left by his, pressing him more firmly against her. His finger slides through her folds, inside of her, and she tilts her pelvis into his hand, rocking against his palm, and now he's the one biting back a moan. He grabs his scotch, drinks down half of it. The alcohol burns through him, makes him want her more and shit he's an idiot. A really big idiot.

"I don't know," Kate responds and he's surprised and a little impressed by how normal she sounds right now. The fire raging wildly in her eyes when she looks at him is the only betrayal of her calm exterior. "What do you think, Castle? Would Gina approve of me showing up as Nikki Heat? Or would that be a little awkward considering?"

Castle nearly chokes because how, how the hell did she one up him like this? Her hand is on his back, smoothing over the ridges in his spine and he's about ready to throw her down on this bench right now, make her come around his fingers. He tries to find the words but they're all bundled up and packaged away in his head and there's nothing left and he's a writer for god's sake, words are his thing.

"What about you?" she asks Chelsea. "Has anyone ever dressed up as Gretchen Lowell for your readings?"

"A couple of fans here or there, but thankfully Black Pawn hasn't forced me into that yet. Then again," she says with a smile, "I don't have a real life inspiration."

Castle has reclaimed some of his balance and takes this opportunity to slide a third digit inside of her. He widens them, stretching her apart and she's dripping into his hand and he's can feel himself straining against his pants and there's no way in hell he can get up anytime soon. He should stop this. Slide out of her. Leave her alone. But she's clenching around him and he can't stop, won't, because it feels too damn good.

And then Chelsea, his angel Chelsea, slides to the end of the booth. "I'm going to head to the little girl's room and then get a drink." She stands up and thankfully they're covered because he'd never live this down. "Do either of you need anything?"

He looks at Kate, her skin flushed and glistening, can't resist teasing her just a little bit more. "Kate? You look a little hot. Do you need water or something?"

That look. Oh, she's going to kill him. Totally worth it, though.

"No, thank you. I'm okay." Chelsea walks away and she lets out a shuddering breath, her entire body shivering. "I'm going to kill you," she seethes.

"Oh, Beckett." He cleans in close, inhales the scent of her, the tart notes of her perfume, the sweet, musky scent of her. He curls a finger inside of her, then another, followed by the third and her walls quiver against his hand and if she's loud out here, oh, this is both the most awesome thing ever and possibly the one that is going to get him killed. Her lips are nearly pressed against his and she whimpers into his mouth, delicate, needy. "Wouldn't it have just been easier to tell me what my present is?"

He watches the struggle in her eyes, the fight between anger and need, and she presses her hips into his hand again, swaying forward. "Can't do this here," she whispers, eyes casting around the room. "Take me into the bathroom. Now."

He's out of her quicker than he's ever been and he needs a minute, needs to breathe, to settle. His fingers are coated with her desire, sticky and wet and he slides them between his lips, eyes never leaving Kate. She groans, resting her head back against the cool wood, her chest rising and falling and how no one has caught them, he doesn't know. He runs his tongue over the pad of his middle finger, swirling it there until he's clean, until there's nothing he wants more than his lips on hers and this really isn't helping him, not when she moans into his mouth, tongue sliding against his.

"Castle," she murmurs, and she pulls away. She moves a little to the right, away from him, inhales deeply. Her head lolls to the side and she's smiling, mischievous. "I'm still not telling you what the gift is."

He can't help it; he laughs. "Don't even care right now, Kate. Bathroom?"