Heartlines

co-authored by Sandiane Carter and chezchuckles

Kate runs behind schedule all day. She woke early and slipped out of bed, managed to drink her first cup of coffee before hitting the shower. Castle followed her (though she expected him to sleep for awhile yet), and that made her late to work.

Really late. It's possible she let herself be distracted. She might have gone back to bed with Castle (entirely his fault; he was so damn eager, and attentive to a heightened and completely all-consuming degree). She might have had lunch in bed with him, and she might also have needed a second shower which led to more. . .activities. . .even though she meant to get to work early.

Sigh.

When she does arrive, there's the paperwork she didn't finish on Friday afternoon waiting for her on her desk. She gets started on that while the boys wheedle her for information about the big event.

Of course they caught a case yesterday while she was at the wedding, but Esposito and Ryan want all the gory details before they will settle down ("Yes, Esposito, Castle cried first - you win the bet"), and when they do finally dig in, the three of them stare blankly at the murder board for a lot longer than is healthy (while Kate wishes Castle were here to nudge them in the right direction with some crazy theory). She even tosses out CIA just to see what happens (nothing, of course; it's never the CIA).

They run financials, start asking themselves why that convenience store's dumpster, why that street, why this normal-looking guy.

No warrants, no judicial process on Sundays, so she's spinning her wheels a little, trying to work around the system's limitations. But she's got uniforms canvassing the neighborhood again, talking to the people who weren't at home last night, and she's arranged for the surveillance tapes from the ATM camera across the street to be delivered the moment the warrant comes through.

There's not much else, but now it's creeping up on six.

Damn. Castle's book signing.

"Guys, I hate to do this to you again-" she starts, grabbing her jacket, then pausing as she glances at the murder board. "Wait. Didn't the girl say something about photographs?"

Esposito raises an eyebrow, glances back to the board. Kate has half-shrugged on her jacket, stilled by the image that slowly forms in her mind's eye.

Ryan flips through his interview notes. "Girlfriend, Randi, says 'I asked him to do one little thing for me and he couldn't even do that-' Jeez. Nice girl."

"Wait, wait," Esposito says, clearly seeing it now too. "That one little thing. The photos. Getting the photos on her digital camera developed. Maybe he *did* get that done. And if so-"

Ryan nods, the light coming on. "If so, where are those photos?"

Kate grins. "Exactly. That's what he was doing there. None of the clerks remember him because you don't need an employee to print out photos anymore. We should check the convenience store's digital photo kiosk. I bet they have some kind of back-up data storage. Have Tech-"

"Tomorrow."

Kate sighs, winces. "Right. A warrant. Damn. Okay, well, put the call in-"

"Don't you need to get somewhere, boss?" Ryan asks, tugging on the sleeve of her jacket. "You looked like you were on your way out."

"Right." Damn it. She really should go to this thing. Castle asks so little of her and- "Right. Yes. I need to go. Castle's signing is over - shit. In five minutes. Espo?"

"Yeah, yeah, we got this. Just phone calls. Go."

She could kiss him. Only he'd look at her funny and Ryan would snicker, and that's-

Anyway. Kate pushes her other arm into her jacket, slides her keys, wallet, and phone into the zip pocket, makes sure she's got her gun and badge, and then she's ready. She wanted to change before she went down to Book Culture, but jeans and an ivory sweater will have to do.

She takes the subway because it's at least slightly faster than walking (and because Castle will have the car service pick them up, she's pretty sure). She climbs the station stairs back up into the close and busy sidewalk, the sun filtering between the buildings and warming her up.

Kate unzips her jacket a little, then has to take it off entirely, throwing it over her arm as she gets close. Book Culture is a squat-looking, modern building with chrome book spines for door handles. She checks the time and risks going inside.

There's still a line, despite the fact that it's late, that this place is kind of out of the way, and that Rick doesn't look so happy. In fact, from her vantage point at the back, he looks dispirited. She wonders if that's because she's so late. But why would it matter so much to him?

Oh, seriously. Of course it matters to him. Kate sighs and drifts to a table of his books, plucks it off the display without even looking at it. She should've kept better track of the time, left when she first meant to an hour ago.

She did warn him she had a lot to catch up on; he knows how it is in the precinct.

Oh, Castle.

Kate gets in line, hugging his book to her chest, swamped in frustration by the way he smiles but doesn't smile, lifts his sharpie to the book jacket to sign one after another without really even looking. He glances at a face, gives a polite nod, doesn't seem to even hear or see the 'biggest fan' at the table in front of him.

A few people are now in line behind her as well, which means he'll be here for awhile yet. He said it might last until seven, so she's not all that late. Right?

The line moves pretty quickly, since Castle isn't even really chatting up anyone. So not like him. He really was looking forward to her being here, wasn't he? She hates that. This is the clingy part she can't stand; she really can't. The kind where his whole attitude changes because she's not there. He's better than that; he's his own person who has lived an entire life before her. He shouldn't be wallowing just because she's a little bit late-

"Who should I make it out to?"

And damn him. He's not even looking at her.

"Kate," she says testily. "Make it out to Kate. Castle."

His head jerks up; his brain must register slowly, because he looks blank and dumb-founded for a second, and then he grins like a little boy, so eager and pleased with her, proud of her, that her irritation evaporates.

"You made it."

"Of course I did," she huffs at him, unable to let it go entirely. "I said I would."

She can hear murmurings behind her; fans catching on, figuring it out. They've been photographed together before; he's known to be living with his Nikki Heat. Whatever. She couldn't care less what they think about this.

"I'll have them lock the doors," he grins. "They were supposed to close at six anyway. And then-"

"Sign my book, Castle." She narrows her eyes at him. "And then, we'll see."

He glances down at the book, seems to pale for a second. "Did you. . .you haven't-" He shakes his head, studies her for a second, then signs the front cover carefully. She watches his handwriting, reads it upside down as he does:

Kate - Only you. - Rick.

He winks at her and hands it back; she leans over the table and kisses him, her fingers at his chin to hold him there even in his surprise. His handler or agent or whatever she is makes a move forward, like she might actually stop Kate (ha!), but Castle is waving the woman away, coming back for another kiss.

"Hey beautiful," he says softly, so only she can hear. "Wait for me?"

"Always," she murmurs back, smiling a little. "I'll be outside, Castle."

Beth sinks her teeth into her lower lip to trap the laugh in her throat, and resolutely looks away from Alex, studies the decoration of the hotel instead.

The lobby is simple and elegant at once, just like the rest of the hotel; some rich-looking people are making their way in and Beth looks down at her own clothes, a little self-conscious.

There's nothing wrong with her outfit – it's actually a very nice Valentino dress that Castle and Kate got her for her birthday – but she's just…not used to it yet. The life of luxury led by these people who regularly spend the night at the Mercer Hotel.

Her eyes find Alex again; he's still talking with the guy manning the desk, casually leaning against the counter. He changed clothes as well, and she loves the deep blue shirt that echoes the color of his eyes, the dark jeans that hug his ass in a rather – appealing way.

They're late already, and yet when he came out of the bathroom wearing those pants, she had to resist the temptation to peel them off him. But, no, they really had to go.

Which brings her back to her present concern: what the hell can he and the hotel employee be talking about? Alex knows they have little time to spare –

Oh. Maybe – but – no.

Beth feels her cheeks flame up, averts her eyes. This is an expensive hotel, right? The rooms must be soundproofed. They must be.

The guy can't possibly be telling Alex that they got complaints about the noise.

Can he?

Because if – if the rooms aren't soundproofed –

Beth presses a hand to her burning cheek, her heart thumping in her chest. She knows she is pretty vocal – always was – and with what Alex did to her last night… Oh. Oh god.

But no, no, she has to be wrong. There's no way –

"Beth?"

She jumps at the sound of his voice, then laughs nervously at her own stupidity.

"What were you talking about?" She can't help but ask, sliding her hand into his and squeezing gently.

Alex looks at her in confusion, his eyebrows knitting as he takes her in. "Nothing much," he says. "The guy offered his congratulations, and I asked if they had a lot of newlywed customers, and we just – chatted. He's pretty funny."

"Oh." She really is an idiot. "Right."

"Why?" Alex asks, arching an interested eyebrow. Damn. Why doesn't she have a poker face like Kate's?

"Nothing," she answers, flashing him a smile that she hopes will distract him.

He moves closer, brushes his lips along the line of her jaw, before whispering in her ear, "Liar."

His left hand comes to rest on her waist and Beth arches instinctively, her body still sensitive and overeager despite her sore muscles. She turns her head and her mouth finds his, the heat immediately thickening between them. Alex pulls her closer and she hums against his lips, presses herself to him as her tongue prods at his mouth, looking for a way in.

He breaks the kiss first, rests his forehead to hers; his respiration is a little jagged, and hers is no better.

"God, Beth," he murmurs, sounding half-frustrated, half in awe. "How can I –"

"Still want you so much?" she finishes in a breath. "I don't know," she laughs, nuzzling at his cheek. "But I want you too."

His arms around her tighten; she lifts her eyes to find his closed, his whole face tense with the effort of holding back.

"Don't say things like that, woman," he orders between gritted teeth. "There's no time. We have to catch that plane. No time."

"Don't call me woman," she shoots back, a giggle escaping her despite her best efforts. "I'm your wife."

His blue eyes open at once, full of adoration and delight; she has to rise on her tiptoes to press a kiss to that smiling mouth, her hands closing on the lapels of his leather jacket.

Something prickles at her thumb; the corner of an envelope is tucked in his inside pocket, she realizes when she breaks away.

"What is that?" She asks curiously, snatching the small, white envelope and turning it between her fingers.

Beth and Alex, it says. She recognizes Castle's messy script.

"Oh, Rick gave that to me last night," Alex says, trying – and failing – to get the envelope back. "When he told me about the Mercer. Beth, he said we weren't to open it before the last day of our honeymoon…"

"Oooh, secrets," she says with a cheeky smile, stepping back to keep the thing out of his reach. "What if I want to open it now?"

She *does* want to open it; they won't get any of the presents before they come back from their honeymoon, and patience has never been Beth's forte. This will make up for the mountain of presents she didn't get to touch last night.

"Beth," Alex scolds when her fingers start tugging lightly – she's trying not to tear it open. "Beth, give it back."

She laughs and gives him an impish look before she runs away from him like a little girl, skirting his outstretched hand and darting through the mini-crowd (all of five people) waiting at the reception desk.

"Beth!"

He catches her just when she's sliding the card out of the envelope, his strong arms circling her waist; he's laughing too, and she teases, "Too late, Mr. Conrad," waving the card at him victoriously.

His disappointed sigh is too heavy to be sincere; he shakes his head at her, still smiling. "Fine, then. Since you can't respect anything."

Beth sticks her tongue at him, then looks down at the piece of paper in her hands.

"Home is where the heart is," she reads. "And it's signed, Rick, Kate and Alexis."

She turns the little card, but nothing else is written on it. Just that phrase, and their names.

"What the hell is that supposed to mean?" she says, confused and vaguely annoyed because she hates not to understand. Alex takes the card from her, looks at it, shrugs.

"I have no idea."

On the verge of becoming thoroughly upset – she really hates puzzles – Beth jiggles the envelope, and catches a glimpse of metal as something falls from it, lands silently on the carpet.

A key. She picks it up and examines it closely; it looks familiar, but she can't remember –

"A key," Alex says, echoing her thoughts. "Do you know what it opens?"

She shakes her head, opens her mouth to say that she doesn't –

– and then it hits her.

She's seen that key before. In her sister's hand. She recognizes the peculiar dented edge, the scratches, the bronze color.

"Kate's apartment," she murmurs, still unsure what meaning she should give to the object.

"What?"

"This – this is the key to Kate's apartment," she says a little louder, her heart stuttering because it can't mean – they can't be –

But the card. Home is where the heart is. The card, and the key. Oh god. She can't breathe. Oh, Kate.

"The key to Kate's apartment?"

Alex sounds absolutely clueless, unaware of the fantastic gift they've just been given (and she thought a night at the Mercer was pretty spectacular) – but she doesn't doubt any more, because this has Castle and Kate written all over it, and even though they're crazy – they're out of their damn minds – this is so incredibly sweet and wonderful and oh - Katie.

"Oh my god, they're giving us the apartment," she breathes, lifting her eyes to Alex and finding that his contours are blurring. Damn her sister and her tear-inducing presents.

"What?" Alex sounds disbelieving – of course – but his hand clenches on her wrist and she can tell that his mind must have come to the same conclusion.

"Alex - Rick and Kate. And Alexis. They're giving us Kate's apartment."

He stares at her for a long, long time, blue eyes wide and mouth open in shock.

"Holy shit," he says at last, looking completely stunned.

"Yeah," Beth agrees, dizzy with awe and gratitude. "Yeah, you can say that again."

Kate leans against the brick edifice of the bookstore, Castle's novel against her chest, arms crossed, waiting on him. It's cooler in the shadow of the building and she's had to put her leather jacket back on to ward off the chill. She's tempted to read the book while she waits, but she'd rather curl up warm on the couch with a glass of wine or maybe even with him, the author, reading over her shoulder. Sometimes he does that (when he's not too sick of his own words).

The bullet scar itches between her breasts, but she knows that scratching it will only irritate it more. The skin at her side - that still aches. The scar there travels along her ribs like a ribbon, and it pulls tight in the cold; she kneads her fingertips into it and tries to be more patient.

She's still wary of the mournful man she saw inside the bookstore this afternoon. Evening. All because she didn't show up until the last minute? Honestly, it doesn't reconcile with the man who persistently showed up at her father's cabin each day, stayed even when she tried to send him home, and finally convinced her to convalesce at his home in the Hamptons.

The morose writer at that book signing also isn't the same guy who danced with her at Beth's wedding reception and casually threw out this invitation. So Kate has no idea what happened in there, but she's going to find out.

She doesn't wait long. Castle exits with a few employees, his smile back in place, and she joins him as they head towards the sidewalk, one arm curling around his book so she can lace her fingers through his.

"Cold," he murmurs, smiling over at her and squeezing her chilled fingers.

"Someone made me wait," she grins back, grateful that it's her Castle who walks beside her, and not whatever that was inside. "I tried to get here earlier-"

"No, I know," he said. "I knew it was possible you might not make it."

"You looked so sad," she says softly, a warning and a question both.

"No. Just disappointed."

Kate flinches at that, turns her head to avoid that look on his face - the look she knows will be there. He said she was enough, more than enough; somehow she has to fight to still believe that right now.

"Not in you, Kate. I just - I had plans, have plans, and it looked like things weren't going my way. I - not you," he says, stopping in the middle of the sidewalk and bringing her up short.

She hazards a look at his face, concern and exasperation and a fair amount of eye-rolling in her general direction. It's a little ridiculous how much she doesn't want to disappoint him, how much she needs to be enough for him, be good enough. Be more.

She feels silly words trying to blurt out of her mouth, leap out into the space between them: I'm trying; I'm trying.

He knows that. She knows he knows that. This is ridiculous. It was just seeing his whipped look in the store-

"Here, wait. Come with me," he says, and proceeds to jaywalk across the street. And Kate, tied to him by their joined hands, finds herself following after.

"Castle-"

"I sort of planned something a lot better than this but - well, this will do. A good story."

A good story?

He stops in front of the open gate to the public park, pushes her inside, herding her towards the playground. She hates to be herded, so she shakes off his hand and pushes him back, giving him a look. "Where are we going?"

"Come swing with me."

"Swing? It's cold out here-"

"Come sit, Kate." He snags the chain of the swing on the right, waits until she sighs and drops down into the rubbery, curved seat of the one beside it before he sits himself.

She splays her legs out in front of her, lets the book fall to her lap, holding it in place with one hand. Kate wraps her fingers around the chain of the swing, tilts back a little to look up at the dimming sky, then leans her head against the chain, her eyes on Castle now. He's watching her intently.

"Have you started the book yet?"

"No. Waiting for you," she admits, letting loose a fluid smile. Her stomach clenches at the answering look on his face.

He's hunched forward in the swing, barely even on it, his elbows on his knees, and he grins back at her. "You look tired."

"A little. You said you had plans?" Dinner maybe. Dinner out? She could really go for Chinese takeout and some wine, a night reading in bed. "I don't want to really go anywhere-"

"Mm, yeah," he shrugs, and she smiles again because he looks like he can do away with his plans if she wants.

Which is nice. But maybe she should make an effort here.

"We can go if-"

"Hey, Kate?"

She pauses, surprised at his interruption, at the way he looks, hands laced together and face both resigned and a little breathless at the same time.

"Open the book."

Open the book? She glances down to his novel, spreads her palm across the glossy cover. For once, Nikki Heat doesn't look naked, but she's still poised Charlie's Angels style with her gun, the city skyline behind her. Kate waits a moment, taking it in, hears the chains of his swing creak, the sharp call of a mother on the other side of the playground, the running feet, the thump of a body on the slide.

She opens the book, flips past the title page, eager for the first chapter (how his books always give her the same thrill that the weird homicide cases do), but she stops on the dedication page - like she always does, and she reads it first.

Please say yes.

Kate lifts startled eyes to find Castle on one knee in front of her, hesitant but determined, his face opened up in expectation and love, filled with a question he already knows the answer to. His hand is pulling a box out of his jacket pocket.

"Kate-"

"Yes," she interrupts, her eyes caught by his.

He laughs, relief and mischief in his voice, catches her even as she slides out of the swing and down into his arms. "You haven't even let me ask-"

"It's yes. Yes. No need to ask-"

"Kate," he chides, but his arms are tight around her, dragging her into his lap as he sits back in the grass. "At least let me put the ring on you."

She laughs back, her chest in a tight fist around her heart, her thrashing, madly beating heart. She knew he would do this, and soon, knew it, but still to have him kneeling down in front of her, to see the words in the book - her book-

He's fumbling at her hand, tugging her finger into the space between them; she drops her head to watch, shell-shocked and thrilled and overcome.

It's not any of the rings she looked at in the artist's studio, but a strange combination of all three. A platinum band with a single diamond inset, but edging the bottom of the ring is a groove that makes the diamond look as if it floats in a sky of silver.

"Is it okay?"

She blinks and lifts her head, lets him see the moisture collecting in her eyes, wipes at her cheeks with the back of her hand. Her other hand.

"I love it."

"That ridge at the bottom - it's supposed to have diamonds in it, but I didn't think you'd like that. But if you want them - it will hold them. And maybe on anniversaries, I could get a diamond or a sapphire or whatever you want put-"

She shuts him up with her mouth against his, the hot, flush feeling of their lips meeting, aggressive and needy. She slides a hand to his back, at his shoulder blade, holding him against her, keeping her warm as the sun sets, while she curls her other hand at his collar, feeling the ring between her fingers, cool and beautiful, the warmth of his throat at her fingertips.

He slides past her mouth to graze her jaw, nibble at her ear. She shivers and reminds herself they're in public, on a kids' playground - not here.

"I'm so in love with you," he murmurs.

She's not sure she's ever heard him say it quite like that, and the molten feeling of her insides makes her curl towards him, her mouth finding that spot under his ear and sucking.

"Ah - Kate-" he groans, pressing her against him with both hands at her waist. "Stop, wait. Stop-"

She hears her own strangled moan, the anguish of not having him right now, but she pulls back, tries to breathe.

She needs some levity. Some humor to crack the lustful tension coiling her body tighter and tighter-

"Okay, so ask already," she says, trying on a smile, seeing his agonized arousal strip away for a look of laughing surprise.

"Oh yeah? I think I already have my answer."

"I'm not sure it counts-"

"Oh, it counts," he says darkly, narrowing his eyes at her. "But just so you can never use that against me - Kate Beckett, marry me."

"That's not a question."

He growls and snags her lips with mouth, a kiss of teeth and his aggressive tongue, but she gives very little and pushes him back before it goes anywhere.

He huffs. "Fine. Will you marry me?"

"Don't sound so exasperated-"

She moves to twist away from him when his fingers go to her sides to tickle her, only it's not helpless laughter, but pain that stiffens her and jolts along her ribs, flares up her back, and damn, that does the job of clearing her head rather well too. Kate leans against him, panting through it, and he stills, cups the back of her head.

"Sorry, I forgot, I'm sorry-"

"I'm okay," she grits out. "I'm okay. Don't-"

But she doesn't know what she's telling him not to do. Don't take it so hard? Don't feel so guilty? Don't stop loving me?

"Kate," he murmurs, his arm cautiously drawing around her, not too tight, his lips at her forehead.

She struggles back from the sensation of pain, wonders why now, why here, with this, hates the scar and the bullet and that whole day-

"I'll marry you," she says instead, her mouth against his cheek, knowing he hears her. "I love you."

She feels his chest ease, his arm not so tense, feels the gentle brush of his lips against her forehead, her nose, her cheekbones, her closed eyelids.

"I'll be better," she promises.

She'll be better than this.

A kiss to the beauty mark under her eye. "You're fine-"

"For you, Castle. Better for you."

Not just the scars on her skin, but the scars on her heart as well.