A/N: The usual disclaimers about not owning anything blah, blah, blah. My prediction for early season 4, spoilers for season 3 finale but honestly who hasn't seen it by now? The smut starts with this first chapter so stop here if that kind of thing turns you off.

Chapter 1

It's past midnight when Kate arrives at his front door like some stray cat hoping to be fed. She only knocks softly as if she's actually hoping that no-one will hear her and then she can leave but he's opening the door before she can even turn back to the lift. He has a closed circuit camera hooked up to his front door, one of the many security measures that he had installed after she came to stay with him as she recuperated after being shot. He can see her coming from his laptop as he waits for her night after night.

He doesn't say anything because he knows that they will just end up rehashing the fight that they always have if they start talking. Instead he just pulls her in so that he can devour her mouth, even as he walks them backwards towards his bedroom. Clothes start coming off by the time they hit his study, the trail of material litters the path to his bed.

They have to break the kiss in order for him to pull her shirt off but then his mouth is back, it feels like a trail of lava as he licks his way down her neck to the upper slopes of her breast. Her hands grip the sides of his head as she directs him lower until finally his wicked tongue makes contact with her nipple. The moist, warm cavern of his mouth makes the tip tighten even further as he sucks on her skin before he bestows the same treatment to the other side.

She doesn't need to tell him what she wants from him, he can read the response from her body like a blind man with braille. In fact the bedroom is the only place where they seem to be able communicate at all these days, outside these walls there are arguments and standoffs; here there is just perfect agreement.

Kate toes off her shoes as he undoes the button and zipper of her pants, she helps him out by doing a little wriggle of her hips as he pushes down her trousers and underwear in one go and finally he has her naked. It takes her far less work in order to divest him of the t-shirt and robe that he was wearing, his erection springs up to greet her as she pulls his boxers down.

Her fingers automatically encircle him, a little cold still from the weather outside but he doesn't feel it, there's so much blood rushing down there it's like a furnace. Rick pushes his hips towards her so that her hand slides down the length of his cock making it swell even more.

"Oh my god Kate," he whispers the blasphemy against her temple; his eyes clenched shut as he savors the feel of what she's doing to him. With an incoherent moan Rick pushes her onto his bed; he pauses for a second to admire the view before he joins her. He starts at her calves, feathering her body with light kisses as he crawls up the length of her.

"Too slow Rick," she complains as she tries to drag him up quicker but he's not going to be denied. It's been four long days since he last worshipped her body and he's going to make her pay for every second that he's had to wait for her. He pauses at the apex of her thighs, inhaling her musk, the smell of sex and Kate which he'll never get tired of. Even before he slips a finger into her he knows that she'll be hot and wet.

The probing of his finger is a tease, even as she reaches down to grab his hand and hold it there, it's already gone, a last flick over her clit making her shudder before he continues with his journey up her body. The torture is too much to endure and her hands try to capture his cock; to guide it into her as she spreads her legs even more to make it easier but Rick knows all her tricks, his hands capture her wrists and pin them to the bed so that she can't tempt him.

Her hands aren't her only weapon though; she switches tactics and uses her whole body to rub against his. Her breasts are pressed against his chest as she writhes underneath him; her legs encircle his hips so that the shaft of his cock is rubbing along the lips of her sex. He may have her arms imprisoned but it's a double edged sword because it means that he can't put enough space between them to avoid the other things that she is doing to him.

"Please Rick, I need you inside me now."

It's the words said in her low husky moan as well as the heat of her body, burning him at every point where their skin touches, the combination is an irresistible lure into sin and he has to give in. Her hands are suddenly free as he lets go in order to reach down between their bodies, taking himself in hand and positioning the tip at her entrance.

Her moisture coats him as he eases in the first inch, the feeling is indescribable; the closest that he can come is to compare it to pushing into warm, honey drenched silk. Rick pauses for a second as he lifts his head so that he can stare into her eyes, waits for her to acknowledge him, and then his hips piston forward, driving him all the way home.

Kate can feel herself stretching around him, a delicious ache as her body relearns the texture and friction of his erection driving into her; the plump head forcing the walls of her sheath to part, to accept the rigid shaft pushing behind it, the extra grind at the end of his downward descent that rubs his pelvis directly onto the over-sensitized nerves of her clit. She can't help the sobs that come from her throat because it feels too good as his thrusts push her to the edge.

His words come out as a whisper telling her how good she feels, how much her little moans and gasps him on, how much he'd like to stay inside of her forever. He's barely coherent and he has no idea how much of what he's saying actually makes sense but he can't help it; the words just want to burst out of him.

They find an instinctive rhythm; her hips rising up to meet him as he thrusts into her, her inner muscles tightening around him which adds to the friction with each withdrawal.

"I'm close … almost there Rick. Harder please!" she can't help the whimper that escapes her as she begs him for more.

He's thrusting even faster now, slamming into her so forcefully that it drives her body up the bed. Kate raises her hands, bracing them against the head-board so it gives her some counterforce to each of his thrusts. She's teetering on the edge and then his next thrust pushes her over and she's diving head first into a blinding orgasm.

His movements stutter as he feels the ripples of her climax tightening around him and it triggers his own. His hips keep moving, jerky, irregular thrusts as his body concentrates on pumping his semen into her, until finally he comes to a complete standstill, buried deep within her warmth.

When she can think again the first thing that Kate registers is the harsh sound of his breath fanning her ear. His dead weight above her pins her to the bed, it should feel claustrophobic but instead it just feels comforting and she allows herself to enjoy it because she knows what she has to do next.

"Stay please," it's the first thing that he says afterwards.

She would do anything to grant him that, anything but put him in even more danger than she already has. She's always careful, watching out for anyone possibly tailing her but she knows that it's not perfect, there could be eyes anywhere. If she stays any longer and there are people watching her then they'll know that this was more than just a booty call. If she stays then they'll know exactly how important Rick is to her and that risks pulling him back into the maelstrom that is her life.

"I can't Rick," she pushes him off her so that she can get up again. Searching out her clothes, she pulls them back on and forces herself to walk away from him. She's still pulling on her shirt when she pauses by the bedroom door, she doesn't look back because she can't withstand the pleading that she knows will cover his face, so instead she takes the coward's way out and gives him her back.

"We can't do this anymore … I'm sorry," and she leaves.

The soft snick of the lock engaging is the only sound as she exits his loft, he doesn't bother to follow her out of the bedroom or argue with her, this is a dance that they have done before. This time will be the last time, Kate makes the promise to herself but she knows that it is a lie even as she says the words. The truth is that she's an addict and Richard Castle is the hit that she needs, she can hold out for a while but she always come back to him.

It's not just sex, if it was purely a physical thing then that would be easy. She could pick up some random guy at a club or bar; substitute one drug for another. The problem is that Kate's in love with him and she can't make herself let go.

She blames it on that moment when she lay bleeding out in his arms. Each beat of her heart pumped thick, hot blood out of the bullet wound in her side, lowering her blood pressure and the blackness edged closer. Her last lucid memory is his voice, "Kate I love you … I love you Kate…"

If only he hadn't said those fateful words, if only she'd lost consciousness a moment earlier and not heard them, then it would make it so much easier to walk away from him once and for all. If wishes were horses then beggars would ride.

"She was here again last night wasn't she?" Alexis confronts her dad the next morning as he stumbles, bleary-eyed, into the kitchen.

He's not sure what gave him away but his daughter always seems to know about his nocturnal visitor. Rick just sighs, none of the women in his life are happy with him at the moment.

"Dad you promised me that you wouldn't do this any more," Alexis continues. "I want you to be there for my graduation, to give me away at my wedding, and to congratulate me on your first grandchild. I don't want to see you put yourself in danger again, how do you think I would feel if something happened to you?" She doesn't understand why he keeps doing this to himself, and to his family. It isn't just him goofing around, playing pretend cop with his video 'murder board' and his 'writer' vest. It became all too serious the day that Detective Beckett got shot right in front of them and her dad tried to put his body in the way of that bullet.

"Alexis, I love you and so I agreed that I wouldn't shadow Kate at her work any more and I'm not. You don't want me there, Captain Gates doesn't want me there, and Kate doesn't want me there. So I'm being a good boy and staying away even though it's killing me because she's still in danger and I can't do anything to keep her safe. But I can't stop seeing her, this is my only link to Kate. It's not perfect but it's all that I have."

A/N: This idea came to me based on an interview that I read, Molly Quinn was talking about how her character is going to make her feelings known in the up coming season. Beckett being shot in the finale has opened Alexis' eyes to what her Dad is really up to and she's not happy about it.