He's oddly nervous, pausing as he reaches her door and considering whether he should simply turn around and go home. It's one thing to stop by unannounced when they're in the middle of a case and he's excited about a theory; it may be a weak excuse even then, but he can usually make it work. But now he has nothing but a small box of comic books and an uncomfortably strong heartbeat and he just needs to knock and get over it. Taking a deep breath, he raps on the door and waits.

For the second time in as many days, the door is answered by a sweaty, breathless Beckett. And for the second time in as many days, he nearly chokes on all the words he wishes he could say. The declaration he so desperately wants to repeat.

"You planning to interrupt all of my workouts now?" For a moment he worries that she's serious, but then she tugs him forward by his sleeve. "No need to stand there with your jaw on the floor. I'm fully clothed."

Maybe he's a terrible person for so obviously confirming her statement, but he can't help but sweep his eyes over her body. She's wearing sweatpants that shouldn't be particularly attractive on anyone, but they're adorable on her, and her bare feet remind him that she's at home and comfortable and so totally Kate in this quiet moment. Then there's the tight white t-shirt that is far too sexy to be considered adorable; the material is thin and the room is cold and the sight is affecting him in ways he'll only be able to hide for so long. Her hair is pulled back in a low ponytail and he can't decide if he wants to wrap his hand around it and pull, or whether he'd rather remove the elastic and run his fingers through her hair while he holds her close.

"Castle? You gonna let me know why you're here, or would you rather join me in some push-ups?"

He startles from his relatively inappropriate reverie and holds up the box he's brought from the loft. "I went through my comic book stash and pulled some that I thought you might like to have."

"You didn't have to do that." He expected the protest, but she's smiling and that's good.

"I know, but you mentioned her and I happened to find these and maybe you already have them…" He trails off, nervous again, but she reaches for the box and peeks inside.

"Elektra," she whispers.

She's silent after that and he has no idea what to do. They're barely getting back to normal after a painful summer apart and he knows she has walls, she just told him that, so perhaps he should back away slowly and leave her alone with her exercise and her superhero. It's probably the smartest move he could make, but he hesitates, and his legs become entirely unwilling to cooperate when her eyes meet his. She's almost solemn as she chews on her bottom lip; he's certain there's something she wants to say if she can find the courage she's always afraid she lacks.

While he waits her out, he brings his hand up to tuck a stray hair behind her ear, noting both the comfortable exhale and the way her eyes fall shut at his touch. It makes him brave enough to drag a fingertip along the side of her neck, across her shoulder, and down the arm that still holds the box of comic books. When he reaches her hand, he lingers longer than necessary, covering it with his palm and brushing his thumb across her skin. Then he pulls the box away and sets it on the steps near her kitchen, leaving them standing too close – to each other and the edge of this thing that they could become.

Unwilling to push her any more than he has, he turns to leave, hurrying toward the door before he can find a hundred reasons to stay.

And then she offers him one.

"I told her not to be so driven by the past that she throws away her future."

He's pretty sure his heart stops for an extra beat, but he continues to face the door and replies with the steadiest voice he can manage, "Hastings?"

"Yes."

"And you think that's good advice?"

"I do." He spins to face her again, just in time to catch the confused tilt of her head. "Do you…not?"

"No, no. I mean, I do. Think it's good advice. I guess I'm just-"

"Surprised that I said that to her because it's the exact opposite of what I've been doing?"

He smirks, as serious as the topic is, stunned that they're having this conversation at all, and even more amazed that she's calling herself out so willingly. "Yeah, something like that."

"So, maybe it's time to change." Her brows furrow, but she holds her hand out and he takes the few steps to return to her, gently threading his fingers between hers. "Time to focus on the future."

"Kate, I meant what I said about finding the people responsible for your mother's murder. Taking a break isn't the same as giving up and we will figure it all out someday. I want you to know that I'm not asking you to ignore your past."

With her free hand, she presses her palm against his heart, looking down at it as she takes a deep breath. "I do know that. But I've made a lot of stupid decisions while wrapped up in this mess, and shelving my feelings for you has been one of them." When she finally meets his eyes again, he sees the tears that have pooled there. "I don't want to make that mistake anymore."

They're kissing before he can even figure out who started it, cautiously opening to each other as they find the rhythm they'd left in an alley several months ago. He's not as surprised when she moans into his mouth this time, but it still causes his hips to press insistently against hers, this kiss carrying far more hope than the last. She clings to him, her hands doing at least as much exploring as her tongue, and it's as if she wants to melt right into him, no longer interested in the space she's insisted upon for so long. He'll happily give her anything she wants, but he needs to be sure.

She practically whimpers when he pulls away, but he quickly leans forward to kiss his way up the line of her jaw. "We can still have a future even if it doesn't begin today."

But her head shakes against his, a refusal to wait any longer. "Today. Now. Please."

He lifts her effortlessly, and she's quick to wrap her arms around his neck while he tucks his hands beneath her thighs. He has no trouble finding her bedroom, though the way she's rolling against him and sucking on his pulse point have him stumbling into a couple of walls. There's still something tentative and precious about what is happening, and when he sets her down on her bed, he stares down at her with a smile he's unwilling to censor.

It takes him a while to move again, so it's not surprising when she gets impatient enough to pull her own t-shirt over her head, her sports bra following immediately afterward. Topless, beautiful, unburdened Kate doesn't necessarily save him from the cascade of fantasies that have distracted him, but he remembers that he can touch her now and standing alongside her bed is a terrible waste of time. He hurries to undress to his boxers, then kneels on the bed and kisses her, somehow easing them both to the middle of mattress even as they're tangled together. She really wants him, the demanding arch of her body into his giving her away, but before he'll grant every last one of her wishes, he has one selfish need of his own to fulfill.

He wants to taste her.

He forces himself away from her and tucks his fingers into the waistband of her sweatpants and underwear. He's painfully slow in removing them – contrary to what most people would guess, he's also incredibly deliberate when he open gifts, patient when it allows the anticipation to build – and Kate whines his name when he finally reaches her ankles and is able to toss the clothing aside. His mouth's journey up the inside of her leg makes her gasp with the realization of where he's headed, and he looks up to meet her eyes, to give her the opportunity to send him home.

But all he sees is the darkness of her pupils, such a sharp contrast to the mid-day sunshine lighting the room, and the flush of carnal need that has colored her cheeks. When she shifts and allows her legs to fall open in invitation, he offers her a grateful smile and lowers himself once more.

Nipping at her inner thigh produces a higher-pitched mewl than the way he suckles just below her hipbone, and both are different sounds from the low moan she makes when the tip of his nose brushes against the crease in between. His mouth is open, wanting, and driven by her scent; her body is weeping with a mixture of arousal and sweat and he's never known a siren's call quite like it. He gives in, dragging the flat of his tongue over her, and closing his eyes in relief.

Her fingers comb through his hair to keep him close, not that he could imagine leaving her now. He brings his hands in to hold her open to him, then gently laps at her opening before moving to her clit, carefully cataloging her reaction when he sucks on the swollen nub. From there he varies everything, alternately teasing and studying, encouraged by a steady string of expletives and hips that refuse to stay passive. She eventually asks for more and he's in no position to deny her anything; he slides two fingers inside and curls them forward while his mouth still works over her without pause. She comes hard against him, her core contracting around his fingers and her flavor flooding his tongue, and he can't help but press his lower body into the mattress in response.

The moment she stops shaking, he withdraws his hand and quickly rids himself of his boxers before crawling up the length of her waiting body. She's still breathless, but he has to kiss her, long and lazy and laced with everything he'll repeat another day. Then he nudges against her entrance until he can bury himself deep, relishing the sensation of her arms and legs wrapped so immediately around him. It slows his thrusts, the almost desperate contact keeping him focused on the curve of her lips, the flutter of her eyelids, and the way she continues to whisper his name. He's not sure whether it's gratitude or contrition.

They rock together, finding joy in the languid pace, so much skin to brush with kisses and promises alike. He finds himself wondering if this slow burn is what will help them conquer the years together. They hadn't given in to the dangerous spark of lust that had existed so long ago, one he thinks would have left them with nothing but ashes and regret, and maybe this intimacy is their reward. There will be time for fast and hard and loud and more, but today is everything he hadn't dared to dream.

He slips one arm beneath her hips and helps change the angle, eager to feel her come one more time before he does. She kisses him messily before she simply lets her head fall backward, her back bowed and legs still crossed tightly over his lower back. Knowing they're both so close, he finally speeds up, driving into her while she directs him with a series of one word commands. Her orgasm hits hard, and the expression on her face is one he wants to see again and again, beautiful in a way that even he can't properly describe. He lets go just seconds later, overwhelmed and exhausted and able to roll away just before he crushes her. They're both still caught up in a bit of a haze, but he finds her hand and clasps it in his.

After a few minutes of silence, she sits up with a huge smile on her face; he barely has the strength to raise an eyebrow in question.

"Stay here. I'm going to grab my comic book collection so we can make a trade. I must have something you don't."

She scoots off the bed and he laughs at the gorgeous, naked woman dashing across the floor. "Excellent. I'm looking forward to seeing just how long you've been enamored with Bruce Wayne."