Because it's been a while since I've written something non-episode related. And I felt like spicing things up a bit. The rating will go up to M, so make sure to put this fic and/or me on your alerts.

Thanks to Andy for betaing and encouraging me through my whiny, writing-M-fic-is-so-hard rants.

Disclaimer: If I wrote this for a TV show, I'm pretty sure I'd get fired.

Sizzling Heat

It's been a brutal summer.

Blistering heat, high humidity, and a long string of disgusting, obscure, and challenging cases. Kate hasn't had any vacation days until this week and Castle has been hard at work on his next novel, meaning that she's been spending a large number of days at the precinct without her partner. And, recently, an increasing number of nights alone in bed as he stays up until the wee hours, frantically scrambling to meet the next deadline. Add all of that together and the result is a grumpy detective, a delirious writer, and a very deprived couple.

But Kate finally has some vacation days and Castle just sent in the first draft of his manuscript late yesterday evening and it was a completely spur of the moment decision but they packed their suitcases at eleven o-clock last night, grabbed a few hours of dead-to-the-world sleep, and woke with the sun this morning to head out to the Hamptons for the week.

They're both beyond exhausted, worked to their limits over the last two months. Between long days of detective work and Castle's promotional engagements, meetings, and manuscript deadlines, they've hardly had any time together. He's been up until three or four in the morning. She's been waking at the crack of dawn to solve murders.

In fact, Kate can probably count on two hands the number of nights they've gone to bed at the same time in the last two months.

(Because yes, they've shared a bed almost every day this summer. And she's staunchly ignoring the implications of that fact.)

But now they have the entire week off, with nothing but the last half hour of their drive standing between them and a week of relaxation, sun, sand, sleeping, and sex. Lots of sex.

Kate smiles to herself at the thought, leans back against the seat and stretches her arms over her head, releasing the knots from her overstressed muscles. She can't help but notice the way Castle's eyes leave the road, flicking down to her chest and back up, out to the road again and then back to her figure, curves accentuated as she arches her back, plays it up for him now that he's watching her.

She's wearing a light yellow sundress, not exactly low cut, but low enough in the front that Castle can just catch a glimpse of cleavage as he glances over again. God, it's been far too long since either of them had the time or energy for a bout of spontaneous I-need-you-right-now sex against the nearest surface. And he wants her. Badly.

From the way her eyes darken underneath his unsubtle perusal, he has a feeling that it's mutual. Very mutual.

Kate relaxes back against the cool leather seat, drops her arms to her sides, but at the last minute one hand takes a detour and lands squarely on Castle's upper thigh. Right at the hem of his shorts.

His muscles tense beneath her touch, and it's a good thing the car is set on cruise because otherwise he's pretty sure he would have just sped up by about twenty miles per hour.

His eyes fall to her hand, jump back to the road briefly before he turns his head slightly to look at Kate. Her body is loose and at ease, head resting against the seat back, face tilted up towards the sun and eyes closed. She's the picture of relaxation, complete with the sun glinting off of her hair and the soft, innocent smile on her face.

But the way her fingers are dancing against his skin, the pads of each digit teasing the soft flesh of his inner thigh, is anything but innocent. She's playing with fire and he knows that she knows it. He can tell by the slight increase in her breathing, the way her chest now visibly rises and falls with each inhale and exhale. The way she's playing unknowing and coy. And to the untrained eye, she's doing a fantastic job of it, but he knows her better than that. Much better.

Her fingers skim beneath the hemline, shifting under the fabric and trailing higher and higher. His muscles flutter beneath her touch, tense with his efforts of self-restraint, and Kate smirks as she feels his leg twitch. She adjusts her arm, allows her fingers to slide further around his leg, and this time his foot actually lifts off the floor in surprise.

"Kate," he groans, dropping one hand to cover hers, stopping the motion of her fingers.

"Problem?" she asks with a smirk, tilting her head towards him, eyes twinkling knowingly as they pointedly drop to his crotch before lifting back to his face.

He refuses to dignify her smugness with a response, instead simply removes her hand from his leg and deposits it back in her own lap. Kate wisely says nothing, allows him a few minutes to regain his bearings. Because as much as she would love to have her wicked way with him right here in the car on the way to the Hamptons...and she has some pretty good ideas about how to drive him wild...she'd also rather not get him pulled over and cited for reckless driving. Or cause him to wreck his car. She can be wild and daring, but she's more of a calculated risk type of girl.

What she has in mind most certainly falls well past that line.

She gives him ten minutes before she's back at it, fingers on his inner thigh, dancing across his skin and leaving pinpricks of fire spreading out from each point of contact. His hands tighten on the wheel, knuckles growing white with the strain, because he's about two seconds away from pulling onto the shoulder and having his way with her right here in the front seat of his car.

It's not a secluded area at all and other drivers would most certainly be able to see what they're up to. It would be stupid and he's really not keen on having someone recognize him and snap a picture of him having sex on the side of the road. Kate would kill him. And despite the numerous other things he's been photographed doing in the past, even he would be embarrassed by this one. His intimate activities with Kate are private, and he wants them to remain that way.

But if she doesn't stop driving him wild, he may not be able to be held responsible for his own actions for much longer.

As if she can read his mind, she chooses that moment to give his thigh a little squeeze, follows it up with a gentle scrape of her nails over his skin.

Castle grits his teeth, jaw clenched, determined not to let her get to him. Well, more so than she already is. Because despite his best efforts, he can't hide all the evidence of what she's doing to him. And he knows that she knows that too. It's evident in the way that she turns her head slightly to look out the side window, watching the scenery pass them by as they draw nearer and nearer to their destination. In the way that her hair all falls over her right shoulder, exposing the long line of her neck to his peripheral vision. In the arousal darkening her eyes that she just can't hide.

But if she wants to turn this into a battle of self-control, he's sure as hell not going to give in this easily. He's on edge, but no more so than she is. Because he knows from experience that for all the front she puts forward, when she gets in moods like this, it doesn't take much to crack her.

He loves that he can do that to her.

And as soon as they get to the beach house, he's so going to make her lose control.

More than once.

Thoughts?