Spoilers for Frozen Heat

The flames of nearly burnt out candles flicker across her bathroom walls, casting wavering shapes over the ceiling and smelling like the telltale signs of fall. Her foot absentmindedly taps a beat into the rim of the tub, bubbles disintegrating between her toes. There's a glass of wine in one hand, a book - his book - in the other and there's something so gorgeous about her like this, relaxed and lost in his words that he can't help but lurk in the shadows, watching.

She turns the pages delicately; he can see the water marks that stain, droplets in the shape of tears. Loose tendrils slip from the bun in her hair and he commits it to memory, needs to add it into the next book or just save it in his brain for those nights they're working late. Her shoulders rest against the white lip of the porcelain and -

"You're lurking in my hallway, Castle." She doesn't look at him, instead turns another page, what looks to be the last. "It's creepy."

He smiles at that, stepping into the room. The rain pounds the windows making the squeak of his shoes nearly silent when he walks to her. "Just making sure your cop instincts are intact."

He leans over the tub, presses his lips softly to hers. Kate wraps her arm around his neck before he can escape and pulls him back to her, the wine bitter and fruity on her red stained lips. He swipes his tongue over it, grins against her mouth.

"Hi," he murmurs. "Got your text."

She brushes her nose over his cheek and he sees the goosebumps rise over her flesh, her mouth releasing his as she sinks further into the warmth of the tub. "You're freezing. You coming in?"

He's already stripping down and she's rolling her eyes, setting the book onto the small table that houses both her glass and the bottle of red she must have opened tonight. She's staring and he considers the slow tease, the twirling of clothes around his finger like he's some sort of stripper but he's cold and it's Beckett so she'll get annoyed and -

"Castle, sometime before the water cools."

Oh, right.

He slides in behind her, the water a burning, welcomed touch. Kate settles against his chest, his arm wrapping around her waist. She smells like lilac scented bubbles, the sweet, subtle vanilla of the body wash she only uses on nights like tonight. He presses his lips to her shoulder, hears the sigh that escapes her lips as she submerses herself in his arms.

"How was dinner with Alexis?"

"Good." He runs his fingers over her ribs and she shivers, sinking further into the bath. His book sits on the end table, closed, finished and she's not mentioning it and he's worried she hated it. This one was more personal and if he got it wrong, if he didn't do her and her mother justice then -

"You're dying to know what I thought, aren't you?"

"It's been four months, Beckett. Gates finished it faster than you did."

"It's not like I've had a lot of time to read, Castle. Not to mention," she turns, a smooth motion that makes her look almost boneless and wraps her legs around his waist. She slides closer, pressing her lips to his ear. "I was having sex with the author. I think you're well versed in how fast I can finish."

His heart skips a beat because she's quite possibly the most phenomenal woman he's ever met. "Oh, that's hot."

"Yeah, you like that?"

"I do."

He kisses her softly, hands pressing into her lower spine. The soft strands of her loose hair tickle his shoulder and she's nearly on top of him, smile stretched across her lips as he slides his tongue between her parted lips. He swallows the soft breath she releases, drags his hands up her back until he's loosening the knot in her hair, allowing it to tumble over her shoulders.

"This is why it's taken me so long to read Frozen Heat," she murmurs. "You start this and all bets are off."

"You want me to stop?"

"It's your ego, Castle."

He leans back and sees the teasing in Kate's eyes; the flicker of candles in her irises that causes them to sparkle, to highlight the green that intermixes with the brown. He can't help but think of who she used to be sometimes, who they both used to be and in the moment all he wants is her opinion on his latest book about her. It's not about ego, it hasn't been for a long time. It's about the way she interprets his words, the affection she has for this life he's created for her, for them. She can recite the Miranda Rights in four languages and verse him on the statutes of criminal cases, but she can also dissect his words, the meaning behind them in ways no one else can.

Castle kisses her again, chaste this time. "Tell me."

"First of all, I can't believe you ended it there. I thought the drop box might have been in Cynthia's music. You kept mentioning it like it meant something but to end there? Do I at least get some clues on what you're doing with the next one?"

"Kate Beckett! Are you only sleeping with me because you want spoilers?"

"Is there any other reason?"

"You mean aside from my ruggedly handsome good looks?"

She rolls her eyes, but she's smiling. She curves her knee so it's sticking out and runs her fingers over his chest, across the broad expanse of his shoulders. "This book was my favorite. Not just of the Heat novels, but all of them. It was different."

"Different how?"

"Your passion was so much more evident. I've read all of your books-"

"Yes, I know."

She narrows her eyes, flicking water at him. "You sure you want to tease me tonight, Castle? Because I'm more than happy keeping my opinions to myself. We can sit here all night and discuss everything but your book." Her lips are smooth on his bicep, the whispering of a kiss across his skin. There's lightening just beyond the window, follow quickly by the slamming of thunder. "Hell of a storm season we're having."

"Okay, Beckett, you've made your point. Also nice reference to my graphic novel. Thank you."

Kate scrunches her nose. "Unintentional." She smiles and lifts her head, the tail end of her hair wet and soapy. "You've spent your entire career writing what we do every day and you're so good at it. But in this one you didn't rely on a case to guide your characters. You relied on the characters to guide your case. There was a murder to solve, sure, but it was all about Nikki."

"It was all you," he says softly.

She tilts her head, brushing her fingers over his cheek. The smile flits across her lips, teasing. "Is that why you killed off two of her exes?"

"Hey, in my defense, it worked for the story!"

"Right, for the story. Was it also for the story when Heat groped Rook on the bench in Paris?"

Castle reaches for the glass of wine, grinning around the rim of it. He probably shouldn't tell her about what he did after he wrote that, how all he could think about was Kate and her hands wrapped around him, the -

Her palm closes around him, her eyes alight with fire as she strokes him. "Wishful thinking," he manages, gulping down half the glass. He slides his hand over hers, wants nothing more to guide her along but instead removes her hand. "Later. I want to know more about -" He swallows, tries to catch his breath because even after half a year he still wants her all the time, loves the sweet caress of her hands, the gentle touch when he needs it, rough and wild and full of life at other times. "Later."

"Ego always wins with you doesn't it?"

"I am Rick Castle."

Kate rolls her eyes. "And you never let me forget it."

Her hands continue their journey over him, intimate and memorizing, and she looks deep in thought. He opens his mouth to say something, closes it quickly because she's working through something, looking for words. She still doesn't speak in the way he does; open, heart on her sleeve but she tries now. She tells him about her past, about her mother, about all the things that had once broken her. She's vulnerable late into the night when he gives her the time to work through it and so he presses his lips to her forehead, listens to the puff of air she releases like she wasn't aware she was holding it.

"You know that - you know you have nothing to be jealous of right?"

It's a conversation he's not sure they should have right now around fizzing bubbles and cooling water. Logically he knows he has nothing to worry about; he knows that she's in this with him, that she's never been so open with another man before. He knows by the way she loses control in bed and lets him see her at her best and her worst. But he's also seen the way men look at her in her heeled boots and tight jeans, the way she provides justice and strength and how he'll never quite measure up. He doesn't bring people justice like Will does with the FBI or find what was lost like Tom in burglary, or Josh with all his life saving cardiac surgeries including hers.

He's just him.

And for once he worries that it's not enough.

"I choose you, Castle," she says softly, but with fervor. "You have to know that by now."

"I do."

Kate takes the glass from the side table and spins the base on her palm. He's learned his about her too; she fumbles with objects when she's nervous about something, when she's unsure of what the right thing is. It wasn't until their first morning alone together that he noticed it, vulnerable and herself outside of the precinct, no barriers held. "I saw what you put on your website. About which book of yours you like best."

"How often do you peruse my website, Detective Beckett?"

"Enough to see some of the ridiculous things you post on there. The blueprint to your living room with battle ground rules to laser tag? A murder mystery game?"

"Oh come on! Like you don't want to play that?"

"Okay," she laughs, "it does look awesome." She takes a sip of wine before handing him the glass. "Do you remember what you wrote in response?"

"I remember."

"People need to know that heroes like that exist. I can only hope that Nikki lives up to her inspiration's inimitable model," she recites and his heart clenches at how much he loves her, how extraordinary she truly is. "If I am an inimitable model, it's because of you."

"Kate-"

"No, let me finish."

He nods, craving her words, her insights, everything.

"When I met you I was alone. I didn't even mind it. I didn't owe explanations to anyone. I stopped investigating my mother's murder but I still lived inside of it every day and I knew it wasn't fair to bring someone else into that. And then you came into my life and you didn't give me a choice. You didn't ask permission. You were just there and I couldn't get rid of you no matter what I did. I know I fought you on the Heat series for as long as I could but I wanted to be her, Castle. She had lost her mother, but she was strong, so much stronger than I was at the time. Your words have always helped me when I needed it even before I knew you but Nikki was different. Nikki was who you believed I could be, maybe you believed it's who I was. You accepted in me in a way no one else ever did. Nikki more than lives up, Castle. She's part of who I am."

There are tears glazing her eyes - unshed - and he pulls her to him, pressing his mouth against hers, keeping in all the words he wishes he could say. I need you. I want to marry you - not today, not tomorrow, but someday. I'm so in love you. He breaks apart her lips with his tongue, tasting her wine, taking from her the things that remain unspoken.

"Thank you," he whispers in her ear, his nose buried in her hair.

"On the bright side now that we're together you can finally put Nikki and Rook into a committed relationship."

"It's about time. I think it was starting to get awkward for them."

"For them?" she asks, eyebrow raised.

"Them. Us. Society as a whole."

Kate lets out a laugh, shifting slightly. She shivers, loosening her grasp around him. "It's getting cold in here." She slides to the other end of the tub, her lithe body stretching as she twists to reach the nozzle. She lets the water drain slightly before turning the faucet on, the heat a nice counterpoint to the chill. "Much better." She doesn't come back to him, instead stays with her back pressed against the opposite her, her legs resting over his. "Can I ask you something?"

"After all the times I've asked you things without permission?"

"I'm nicer than you."

"Says the woman who has threatened to shoot me on numerous occasions."

"You deserved it."

"Probably." He smiles at her, running his foot over her thigh. She glares at him, knocking it away, muttering something about dry feet. "Ask away."

"You write your characters so close to the vest. Rook, Nikki, Raley, Ochoa, Lauren." She laughs. "Captain Irons. I can't believe Gates praised the book the way she did considering."

"I think those dolls had some sort of magic power that made her nice. Or they were laced with crack. God, they were so creepy."

The smile fades and she cocks her head to look at him. "So then why Nikki's dad?"

"Why Nikki's dad what?" And then he realizes what she means and he should have discussed it with her before he wrote it, but it's fiction and shit if he had known he was going to start dating Kate right before this came out he probably would have done some damage control. "Kate, I - Has he read it?"

"Right after it came out. He didn't mention it to me, but I - I know it's fiction. I know you did it for storyline reasons. Even I started to wonder if he was a part of the conspiracy by the end. It just made me think of who my dad could have been had he not gotten sober. What our relationship could have been. You do this, Castle. You hit emotions so close to home, things I've never told you and it knocks me on my ass sometimes. There was something you wrote in Nikki's therapy that was so dead on I actually had to wonder if you had the room bugged."

He can't help but smile at that because - well, no, he'd never go that far. "I'm a little less intrusive than that." She gives him that look, the one he's gotten so used to, the one that no longer scares him but turns him on. "Okay, I'm not but I would never bug your therapy. Maybe your apartment so I can hear your girl talk conversations with Lanie-"

"You wish."

"You could just tell me."

"Girl talk, Castle. Keep dreaming." They let the silence settle between them, nothing but the storm, the sizzling of a candle as it slowly reaches its end. He can't help but stare at her, the way her head is lolled onto a shoulder, her hair loose and wet, her body relaxed. She feet are started to crinkle on his thigh and it makes him think of growing old and life and - "It was the last couple of pages," she says, interrupting this thoughts. "You had her therapist - Lon King, Castle? Really? An anagram for Klingon?"

His mouth opens in shock. "How did you even figure that out?"

"Because I've been dating you for months and we were friends for four years before that. Of course you would reference Star Trek in some completely unconnected way." Kate lifts her head and her finger dance along the water, no longer bubble filled. "You can't. She's dead. Burke said that to me in one of my sessions. That I couldn't let my mother down because she's dead. You know me so well that sometimes it's- it's," she pauses, fights to find what she's looking for.

But he knows, because they're in this together. They always have been.

"Scarier than anything else you've experienced before because if I know everything, there's a chance I'll walk away when I've had enough or I've learned too much. But it also means I've stayed through all the demons you've battled, all the things you kept hidden from everyone else. You were once someone I never thought I would understand, Kate. Every time I made some sort of headway, I turned a corner and there were a million other things I didn't see coming."

"So what changed?"

"You. You let me in. You still surprise the hell out of me. You will always surprise the hell out of me, but I know you now. I understand you. And I'm not going anywhere either." He sees her accept this with the nod of her head, the smile she gives him; as much as he loves the words, loves when she uses him he also knows they've said so much without it as well. That it's part of who they are and for tonight, it's more than enough. He lifts an arm out of the bath, scowling. "I take that back. I'm not going anywhere except out of this bath. I'm getting wrinkly."

She looks down at him, the smirk creeping across her lips. "We can't have that. I have plans for you tonight."

Oh, does she now.

"I'm listening."

She steps out of the bath, the water dripping down her body, the easy way she moves as she reaches for a towel. She wraps the fluffy white cotton around her and leans down, kissing him softly. "You dedicated another book to me. I have to pay you back somehow."

"Who said it was about you?"

She throws him a towel as he steps out of the tub, wet footprints staining her tiles before disappearing completely. "How many other women do you call remarkable, maddening, challenging and frustrating? I can't believe you remembered that, by the way. The exact wording."

He doesn't need to tell her that he remembers everything about the day: the way she had accepted his invitation to watch movies like it was a date; her hand wrapped around his knowing they were so close to something; the realization that the man they were looking for was the one who had shot her a year earlier; the look in her eyes when he reveled the secret he had been hiding for far too long; losing her; finding her.

Getting her.

"I had been wanting to say that you for years. Of course I remembered it." She looks up at him with a smile and he can't help but pull her against him, arms wrapped tightly around her waist. He forgets how small she is without her heels, how she fits so perfectly in his arms. "I'm sorry," he murmurs, kissing her temple. He doesn't want to go back here, but he feels he needs to, needs to make her understand. "I hope you know how much I respect your father, how much I -"

"Castle." Kate says, shaking her head. "I know." She squeezes her hands around his back, bringing him in closer until there's no air, until there's nothing but them. Her lips whisper across his skin, goosebumps rising over his flesh. "I also loved the CIA stuff. I loved the complexity of it and I really loved Cynthia's character. My mom would have too. She would have gotten such a kick out of all of this."

"It's a good thing I made Nikki less slutty than I originally intended."

He can feel her smile stretch across his chest. "Only because I would have killed you otherwise. Would you mind draining the tub?" She's out of his arms then, the chill from the apartment, the night, the loss of her body heat causing him to shiver. She blows out the candles around the room, one by one, darkness filtering into the space. She walks to the doorway, dropping her towel. "So, Mr. Castle. Do I get a private autograph session now that I'm done reading?"

"Can I sign your chest?"

Castle sees the smirk before she turns completely and walks out of the room. He lets out a puff of air on an exhale, looks around the room because he knows there's something he should be doing. Right drain the tub. He pulls the stopper out, the whir of water emptying the tub. He's about to walk out when he sees the pen and paper next to his book, an emergency set in case the boys had called with a case. He looks out into the hallway and then back, picking up the pen and opening the book to the dedication page.

To all the remarkable, maddening, challenging, frustrating people who inspire us to do great things.

The smile grows wider as he scribbles his message. She won't see it for a year, maybe two. Not until she re-reads the book again or he urges her to check it. Not until the time is right.

"Castle," Kate calls out, "You coming or do I need to start without you?"

The pen fumbles and he'll have to remember this, not that he'll forget. He signs his name quickly and shuts the book.

"Just grabbing a pen!"