A/N: I stumbled on this excellent Season 3 prompt by Castlefied Forever on Twitter and it tickled me, so I decided to run with it as I'm sure a few others will as well. The prompt is described at the end.

Scentient Beings

She doesn't do this job for the rush of it, for the adrenalin high that comes after a foot chase, when she dives through the air to bring the bad guy crashing to the ground beneath her. She's doesn't live for those heart-stopping moments when she's forced to take aim, hold her weapon steady, remembering to breathe as she looks the guy in the eye then has to fire anyway because he won't toss his gun to the ground. Those instances are not what her job is about; they're not why she signed up when she was lured down this path like Gretel following breadcrumbs after her mother died. And yet, today, standing hand-in-hand with Castle, facing down a dirty bomb, all out of options as their lives and the lives of countless New Yorkers ticked inexorably towards extinction…now, today, she's rarely felt more alive.

She feels him squeeze her fingers in a bone-crushing grip when he gambles everything, acting selflessly and on both their behalves when pulls the whole colorful spaghetti of wires at the very last second. Her stomach drops, her entire body chilling with fear right before everything rises all at once. Relief, euphoria, hysteria that has her laughing in amazement as they fly into one another's arms, hugging more fiercely than any hug she's every experienced in her entire life.

She inhales the scent of him, lets herself drown in the exquisite joy of his embrace, the power of which is overwhelming. His cheek is pressed against hers, stubble grazing her skin, sending erotic messages coursing through every nerve ending in her body. Her nose finds a warm home against his neck inside his collar, and she's surprised to find that she wants to stay here. She wants to freeze these precious seconds on this busy Midtown street because, in this moment, nothing else should exist, nothing but the two of them, hugging and laughing until they pull apart and Castle points at that bomb, so amped, so wired with a hilarious I schooled you expression on his face that has Kate falling about laughing even as her knees go weak and tears clog her throat.

Later, at the precinct, they regale the boys and their captain with an account of Castle's reckless act of courage over bottled beer and boisterous bravado. But when her partner looks at her and tells the room that he knows exactly how lucky he is, she feels her face heat and, for once, she doesn't hate the attention. She revels in his gaze, feeling her whole body grow warm and her heart swell inside her chest with love and gratitude for her luck at finding him.

They see Fallon off with friendly words meant to bury the hatchet and discourage the FBI agent from ever darkening their precinct house again. Then, finally, it's just the two of them, all smiling eyes and still high as kites as they stare at one another. No words are needed; they're forever linked by the life-threatening experiences they've shared. But Castle is a man of words, and so words there will be. "One helluva day" doesn't entirely sum things up, and yet it does if you were there as they were, fighting the good fight together.

Castle tilts his head at that adorable angle, eyes sparkling with mischief and humor. He stuffs his hands into his pockets, perhaps to protect himself from disappointment, before he says, "You know, I was thinking…"

Kate holds her breath because she's been thinking, too. She's been thinking about him and them, and what a good team they make. Her eyebrows lift in anticipation when he says, "I was thinking maybe…"

She's confused by the sudden dimming she catches in Castle's eyes, the resigned, almost fake set of his smile, puzzled by the verbal then physical withdrawal he performs right in front of her.

"…I should go home. Get some rest. Long day," he says, his voice breaking. "Goodnight," he adds in a hoarse whisper, already backing away from her.

No. No, no, no, she thinks to herself. Say what you planned to say. Do it for both of us. Please, Castle? Don't stop.

But as much as she's been thinking she's also been forgetting, and it's not until Castle turns and walks away and she feels something brush her hair that she remembers. Josh, the boyfriend she had conveniently erased from her mind, kisses her cheek and pulls her into an awkward hug. Over his shoulder, Kate twists to watch Castle retreat. Her heart aches with regret as he boards the elevator alone and she sees him slump against the back wall, sad and resigned.

He should not be alone. Not tonight. Not ever. If she's honest with herself she knows the reason he is alone. That reason is her. She's relied on this knowledge to buy herself time. But she knows that she has to make a choice, and soon. Leaving it any longer is beyond cruel to him, and difficult for everyone else involved.

Cool air brushes her cheek as Josh suddenly pulls away. The woody, musky smell of his leather jacket is in sharp contrast to the soft brush of Castle's cashmere sport coat against her skin. She frowns when she sees the expression on her boyfriend's face. His nose is wrinkled, his mouth contorted by something like disgust. She pulls back, embarrassed, brushing her hair over her shoulder.

"I should probably shower before we go out," she says, plucking at the front of her sweater.

Josh doesn't step in like he would have done in their early days together to reassure her that she smells great, that he likes the scent of fear on her as much as he loves her perfume or shampoo. Instead, he says, "Mm, maybe wash that man right out of your hair," tipping his strong chin up and jabbing it towards the departed elevator car.

Kate can't quite take in what he's saying. She laughs, puzzled and slightly nervous, guilt that doesn't belong to her rising to the surface to flame her cheeks with heat in any case.

Self-consciously, she takes a step away from him in case she's reading the situation wrong and she really does stink. "You…you don't mean Castle?" she says, and the reason he ran out on her sinks into her adrenalin-addled brain as soon as his name passes her lips.

"That cologne might work for him. It's a little…floral for my tastes," he says, stepping in close again, landing his hands on her shoulders with a possessive weight and shaking her lightly to soften the edge of his words. He only does this because he can see the look of horror on her face Kate suspects.

She lifts her arms. The move is textbook, unarmed combat 101. She doesn't mean to hurt or scare him, but he looks shocked nonetheless when she knocks his wrists off her shoulders and his arms fall back to their sides. "Whoa!" he exclaims, backing away from her. "What was that?"

"Are you saying I stink? Or are you saying that I⏤" Exasperated, unable to say the words she leaves it dangling. "Josh, what are you saying?"

When raises his voice Kate feels several people turn to look their way. "I'm saying I can smell your writer friend all over you. There. That clear enough?"

And just like that, he's burst the bubble she's been trying to find a way out of. He doesn't care that she almost died, he doesn't care that her partner saved the city when the NYPD and the FBI were fresh out of ideas. All he cares about is his own ego, his stupid jealousy, and a lingering hint of citrus cologne.

Kate takes a deep breath and crosses her arms protectively over her stomach while Josh fumes in front of her. Quietly, eyes on the floor, she says, "I think we're done here."

Josh shakes his head in disbelief. "Wh…what? You're breaking up with me?"

Kate stands her ground. "I think we both know this has been coming."

He gives her a slightly amused look. "Just what were you two doing today? Your hair, your clothes…they reek of his cologne and…now you're dumping me?"

Kate keeps her answer short and her voice under control. She works here. She does not want a scene. "Like I said on the phone. Or were you even listening to me? Castle disabled a dirty bomb today. With his bare hands. We shared a hug when we weren't blown to tiny pieces. I'd ask if you're okay with that but, as I said, we're finished. I don't answer to you. This is over."

Castle has barely got his shoes off and his jacket hung in the closet when the buzzer sounds. Now that the adrenalin has washed out of his system he feels bone-tired. He trails to answer the front door feeling like a man twenty years older than the one who left the loft this morning. His surprise at finding Kate standing on the threshold is written all over his face. His heart has a poor memory for hurt and so it performs a little leap at the sight of her. But Castle isn't counting his chickens.

He lounges casually against the doorjamb, trying to hide his crushing disappointment at the way their day had ended. "Hey. I thought you'd be out celebrating life with Doctor Motorcycle Boy," he says.

Kate shakes her head and looks down at the floor. When she looks up again there are tears in her eyes. Tentatively, Castle reaches out to touch her arm. "Want to come in and talk about it? I have ice cream?" He wiggles his eyebrows and Kate laughs, a short watery snort.

Castle tilts his head for the second time that day. It's still adorable. "What? Suddenly you don't like ice cream?" He pantomimes looking out into the hallway behind her as if a different Kate might be hiding out there, the Kate he loves, the one who loves ice cream.

Now that they're so close she lets herself touch him. She can already smell him, on herself, in the air surrounding her. Her heart is racing, but she's never been more certain that she's making the right decision.

Castle covers his surprise at this newly handsy version of Kate Beckett well. "I have booze, too. Lots and lots of⏤"

They're both laughing as she pushes him and they stumble inside. She clutches his arm as she follows him down the steps towards his kitchen, allowing her hand to slip down to meet his until he's towing her palm-to-palm towards a stool.

"Name your poison, detective," he says, leaning across the kitchen island towards her. It's too broad an expanse for her to reach him, and she did come here straight from breaking up with Josh, but she wants to make her intentions clear, and there are things he deserves to know.

She waves her hand, signaling for him to choose. "Wine…gin…just whatever you feel like. You choose." Because she trusts him with her life, and she knows she can trust him with this, too. He knows her better than anyone, quite literally.

He cocks an eyebrow, a devilish grin slinking onto his face. "Are we celebrating?" He catches himself and sobers for a second. "Or…" He frowns and looks at his watch. "Sorry. I'm being presumptuous. Do you have to be somewhere?"

Kate sinks into her bar stool and slumps onto the counter, balancing her body on elbows. There's a clatter as her high heels tumble to the floor. Castle's eyebrows jump in concert this time in a kind of oh, it's like that expression.

Kate splays her fingers on the counter in front of her and takes a deep breath. She smiles and sits up straight. "Yes. We're celebrating." She nods affirmatively.

"Okay. Just to check. What are we celebrating?"

"We need a reason?"

"I…I guess not. You're here. I'm here. That's as good a reason as⏤"

"I broke up with Josh," she blurts. She presses a hand to her heart as if the words had come from there. As if she's surprised herself as much as she just surprised Castle.

"Wow. It really is a big day." He catches himself. "I'm sorry. Are…are you okay?"

Kate nods again. "I'm…I don't want to sound heartless, but I'm good." She smiles a little guiltily because she doesn't want him thinking less of her. "Really good, actually."

"Oh." Castle sounds surprised. "So this is a drown your sorrows, breakup drinking session we're having? Merely clarifying so I pick the right booze."

Kate watches him with amusement before guilt pricks her conscience. She has to be clear with him. He's waited long enough. "No one's drowning their sorrows tonight." She presses her lips together to quell another smile. "Well, not either of us, I hope. I didn't come here to cry on your shoulder, Castle."

"Then " He clears his throat. "Why did you come here?"

There's a quiet tension in the loft as Castle waits for her answer and Kate takes a moment to formulate the right words. The weighty silence is broken by the sound of her slow, steady exhale.

"I came because…because you're the only one I want to celebrate life with. I came because…" She smiles a little goofily and tilts her head in the way that he does. "Have I ever told you how much I love your cologne?"

When she holds her hands out to him, he rounds the island in seconds. She opens her thighs to allow him in closer as she buries her head on his chest, nudging her nose in between the buttons of his shirt so that she can inhale all of him into her lungs and imprint even more of him onto her body.

He embraces her warmly, snugly, his face buried in her hair, his large hands stroking up and down her spine, tracing the contours of her waist, her hips, down along her right thigh. Her heart is hammering again. When she closes her eyes she can see it and it renders her breathless. "I'm right back there. Today. The bomb. The van. Rick, what if⏤"

He holds her even tighter, whispering, "Shh, we're fine. I'm right here," into her ear. When he kisses the top of her head they both go still.

Kate pulls back just far enough to see his face. She glances over his shoulder at the refrigerator. "Is there a bottle of Champagne in that thing?"

Castle nods his head rapidly. When Kate slides down off the stool in front of him, meaning but not meaning to graze his entire body with her own before landing softly between his feet, he groans loudly, and she grins. "Bring the bottle and two glasses."

"Where are we…?"

He follows her gaze when her eyes swivel. "Bedroom's that way, right?"

Castle feels like shooting himself for saying this but it still feels like the right thing to do. "What about⏤"

Kate waits for him to say it. When he doesn't she says, "Josh?" and Castle nods, growling under his breath in exasperation. "If you have a problem, I understand."

"No problem here. It's…you just broke up with the guy."

Kate sighs and drops her forehead to rest on his bicep before she squeezes his arm and lifts her head up. "Castle, if you think this is a rebound thing…" She looks him hard in the face. "It's not. It's absolutely, one hundred percent not."

"And what about…you know."

Kate sighs again. "In my wildest dreams, I never imagined I'd have to persuade you."

"You have wild dreams…about me?"

She does at least blush for that. "We'll get to that later. Look…Josh and I have been in trouble for a long time, and with our schedules…let's just say there is no crossover. So…" She holds her hand out and waits for Castle to take it. She brings his fingers to her lips, pressing a kiss to his knuckles. "Want to bring the Champagne and join me in bed so that we can start celebrating life?"

The way he touches her is exquisite. Her brain can't keep up, her senses are overloaded, her nerve endings on fire as he gets to work exploring and cataloging this whole new layer of Kate Beckett splayed naked across his sheets. He takes his time, boy does he ever, hands everywhere at once, short nails scratching, the pads of his fingers stroking, his jaw, his tongue, his teeth. There is no ounce of him he will not draw on to bring her pleasure.

She lets him lead for a little while, cedes control; he is overdue. When the tables are turned, she crawls all over him, skin-to-skin contact that has him arching off the bed to connect with every last inch of her. She grins wolfishly when his head lolls against the pillows and his eyes roll back in his head, his shudders wracking both their bodies at once.

"Why today?" he asks her later. She is pressed against his side, both of them sticky with sweat, her leg thrown over his thigh, her arm across his chest, fingers tormenting his nipple.

She's not sure how to answer without bursting their bubble. She doesn't want to talk about Josh anymore. He's a detour in her life. Now that she's found her way back to the main road, there's no point in looking back. But honesty is Castle's code, his credo, and she wants it to be their code, too. So she'll tell him what he needs to know and then they can bury that memory together.

"He smelled your cologne on me today."

Castle shoots up onto one elbow, dislodging her.

"Really?"

He seems more delighted than upset.

"Uh, yeah," she says, amused by this display of masculinity from the man she loves, a man who is such a complex mix of yin and yang. "He didn't like the floral scent."

"And yet he knew it was mine," he states proudly.

Kate laughs. "Claiming your territory, Castle? Spraying your woman like some…some⏤"

He goes for her, tackling her onto her back in a fit of wriggling and giggles. He mauls her neck with kisses as she writhes beneath him. "Like some animal," he growls into her ear. "You like that?"

They collapse into an exhausted heap, a tangle of limbs that feels so natural in a way that is shocking this early on.

When he opens the bottle of Champagne, they toast to the life they have, to the lives he saved today before Kate lifts her glass to his, toasting the future she hopes they will share from now on.

Castle buries his face in his glass, tipping his head back, allowing the bubbles to burn down his throat and tickle his nose. And in the dusky light of the bedroom, Kate smiles to herself when she spies a single tear glittering as it slips down her lover's cheek.

The End

Prompt: DMB smells Castle's cologne on Kate, he gets jealous so she breaks up with him.

A/N: I hope you enjoyed that trip down memory lane. The scene where Castle disarms the bomb is one of my all-time favorite Caskett moments. That hug and the look on both their faces right after, ugh! I'd love to hear your thoughts in reviews. Hope everyone is well and happy. Liv