Thank you to Ana for the tweet of inspiration and to those who were kind enough to support this idea.

Set anywhere between 4x19 (47 Seconds) and 4x20 (The Limey)

Rick takes the subway to the precinct that day because he knows it takes longer than walking or hailing a cab and the more time he spends away from her, the better. He had actually planned to stay home today, but Alexis is in school and his mother kept shooting him those knowing looks, as if she could see straight through his resolve to permanently flip that switch inside his heart. He wants to turn it off, wants to stop loving her so badly, but it's not working.

He thinks it may actually be making him feel even worse.

So when Beckett had texted him about a new case a few hours ago, he'd decided to show up this time.

Over the past week he had been skipping out, claiming he had to write or that he simply just didn't feel up to coming in. Sometimes he doesn't respond to her at all, but there is a knot of guilt, always alive and present, that grows and flares in his stomach every time she texts him. His silence fails to deter her, but with each passing day, her words have become more and more impersonal, as if she doesn't think he'll even read them, and it always has him longing to just drop all pretenses of not caring for her, race back to her side and apologize for his behavior, accept that they'll never be more than partners.

Castle sighs and leans back against the seat while he waits for the train to start moving.

He can accept that, can't he? It's not her fault that she doesn't feel the same, that she doesn't love him back, but why did she have to lie about it? Why couldn't she have just told him the truth that day on the swings? He knows Kate, almost as well as he knows himself, and most times, he can understand her choices, the way her mind works, but he just can't comprehend why she would handle his heart with such flippancy.

The last few passengers squeeze in through the sliding doors and he glances up to study the fellow commuters in the car with him, but when he lifts his head, the first thing he notices is Esposito through one of the windows, right outside the double doors, looking not only frustrated, but slightly panicked.

The train starts to move before he can catch the other man's signal and Castle pulls out his phone, about to dial Espo's number when there's a commotion near the front of the car, yelling and horrified gasps, and that must be why Esposito had been rushing for the doors of the train.

There's a man, a suspect he assumes, holding the transit cop's gun and pulling the emergency brake. Castle grasps for the metal railing at the edge of his seat to refrain from sliding to the ground as the train car comes to a screeching halt, but once the train steadies, Rick hastily returns to his phone, abandoning Esposito's contact for another.

If this is turning into a hostage situation, he knows it's only a matter of time before his phone gets confiscated, and he needs to make one last call.

"Esposito just called me, where are you?" she breathes, and she sounds so scared, so worried, that any vestiges of anger he may have held for her this morning turn to dust.

"Kate," he murmurs, keeping his eyes on the man at the front of the car, the gun trembling in his hand. "I'm in the subway car-"

"No," she moans, agony ripping through the single word, and he swears he can hear her breathing falter through the phone line, hitching harshly in her chest, and he wishes he would have walked to the Twelfth like he always does. He wishes he would have picked up her coffee order and made her smile while he handed it to her, fingers brushing, sparks of something he refuses to call love flickering between them. He wishes he could at least see her again, even if it's to be the last time.

"Just stay on the line with me," she instructs after a deep inhale, more in control, and he can hear the click of her heels, the bustle of the precinct all around her as she strides through the bullpen. "Our tech analyst says we have eyes on the car you're in and we'll get you out of there, okay? I promise you, Castle, we'll-"

A ripple of gasps, cries, and a few screams fill the car and he jerks his attention back to the man with the gun, his heart dropping to his stomach.

"Beckett," he breathes out. "He's wearing a bomb."

"I see it," she murmurs, and he can tell it's through gritted teeth. "I see you."

"It'll be okay," he whispers, closing his eyes for just a second, calling back memories of her face from happier times, from when he was still making her smile rather than causing her lips to curl downwards. "No matter what happens-"

"No," she hisses. "Don't - don't sound like you're saying goodbye. Listen to me, the man with the bomb, Jared Stone, is our suspect and the switch in his left hand is a detonator switch." Castle turns his gaze towards the device she's talking about, watching it shiver in Jared's hand just like the gun. "Gates is contacting homeland, we'll send someone out there, someone who can-"

"Kate, I hope you're right, I do, but I don't… I don't know if I'm making it out of this one."

Gates' voice cuts through the background noise he can hear, a sea of other demanding tones adding to the chaos, but he still catches the choked noise of grief that escapes the woman he's on the phone with. He doesn't see her cry often, but he knows the signs, the sounds.

Jared Stone is barking out orders, telling everyone to hand over their phones, and he whispers her name.

"You promised me you'd watch out for Alexis-"

"No, no, stop," she growls. "I'll go down there myself and get you out, Castle, I swear to god-"

"And I'm sorry for how I've been acting this past week, for how I've treated you. I'm sorry."

"We'll talk about it when you get out of there, do you hear me?"

Stone is walking down the aisle of the car, collecting phones from each passenger, and he presses his in closer to his ear, as if that will ensure that his next words do not go unheard this time.

"I love you, Kate," he murmurs softly, the words he's kept swallowed down for almost an entire year finally slipping from his lips. "And I promise if I make it out of this alive, I'll tell you when neither of us are on the brink of death, okay?"

The phone is snatched from his hand before he can hear her response.

Why the hell does he keep ending up in hostage situations?

"Detective Beckett."

Kate wipes at her eyes and turns to her superior with a nod, hoping the captain won't notice the lack of professionalism, but Gates stops her with a hand on her shoulder before she can pass the other woman to return to her desk.

Ryan is going over Stone's apartment, trying to determine their suspect's motive through his belongings, Esposito's working with the hostage rescue team, and she needs to keep investigating the case, solve Paul Reeves' murder, and understand why Stone is doing this. But her mind is racing, stumbling over Castle's last words, over and over again until her chest grows so tight that she can barely breathe.

"We'll get him back," her captain assures her, surprising her with the gentle touch of understanding in her voice. "Though I loathe to admit it, Mr. Castle is smart, persistent, and by the looks of it, he has another cop on his side." Kate glances back to the computer screen, sees Castle sitting beside the transit cop on the floor, the two of them exchanging quiet words while Jared Stone paces at the front of the subway car, taking another desperate gulp from his inhaler. "Now, what's his favorite kind of pizza?"

"Pineapples and pepperoni," she answers automatically and Gates offers her an encouraging smile.

Kate watches the captain stride back to her office, grabbing for her phone the moment she reaches her desk, and Beckett turns back towards the screen, allowing herself a moment to study him.

He's been so cold towards her lately, ever since the bombing case, and she had come to accept that he must be tired of waiting. It's the only explanation that makes any sense, the only reason she could come up with for why he's decided to punish her with resentful glares and bitter remarks he's been passing off as jokes. She hadn't even expected to see him today; he hadn't answered her text about a body a couple of hours ago – he never does anymore – but when Esposito called her from the subway platform, hope had blossomed deep down in her ribcage at the mention of Castle. He had been coming to the Twelfth, taking the line that would have brought him here to her, but then her colleague's voice had turned gruff as he went on to reveal how he lost their suspect, how he had watched him bolt onto the same car he had caught a glimpse of Castle sitting in. Her wounded heart had splintered in her chest, hope turning to ash, and now all she has left is her drive to solve this case and get him back.

And his love for her, she has that too. He still loves her and he's damn well going to say it to her when they're both safe and sound and together again. She's so desperately ready to finally say it back.

"Tori, can you replay some of the earlier footage of Stone in the train car for me?"

The tech analyst nods and scrolls back through the footage, confirming her fears of Stone's worsening condition. Kate pulls her phone from her jacket pocket, dials Lanie's number with shaking fingers.

"Lanie, has Javi filled you in on the hostage situation, because I need your help."

Castle shares the note from HRT with Marisa the transit cop sitting beside him and in hushed whispers they come up with a plan while Jared Stone argues with Bob the hostage negotiator. He's imagined situations like this before in his head, mostly for his writing, but usually with him as the hero who saves the day, takes the bad guy down, and is praised for his victory, but as he recites the plan back to Marisa, he doesn't feel brave, not at all. He's terrified. Fear pounds through his veins at the thought of everything that could go wrong, at the thought of the stolen gun going off and hitting him or any of the other people on this subway car, at the thought of Stone's grip on the kill switch going slack and blowing them all to pieces. So much depends on him and there's no room for even the slightest of errors.

The red light flickers. Jared hangs up on the negotiator, turns his back to them as he takes a puff of his inhaler, and Marisa meets his eyes, nods, and they both make their move.

Her heart stops when Stone shoots out the camera, her only connection to Castle severed by the single bullet, and she rubs at the scar beneath the thin fabric of her sweater, trying to loosen the knot in her chest.

"There has to be a way to get him back," she murmurs, more to herself than Tori the tech analyst at her side, but despite the frantic sweep of the other woman's fingers across the keyboard, the screen remains black.

"I'm sorry, Detective Beckett, there's nothing I can do."

She wants to break something.

"Yo, Beckett, it's okay," Esposito tries to assure her as she paces out into the bullpen, heading for her desk, dialing Castle's number. She'll talk to Stone herself, she'll hunt that man down if she has to, and if anything happens to Castle… she'll make his life a living hell. "We've got the HRT team on the scene and-"

"And we lost our only visual on them," she snaps, too loud, her voice causing the bullpen to fall silent, but she doesn't even notice, doesn't have the will to care. "That's my partner in there and we-"

"You think I don't know that?" Espo replies calmly, that knowing look in his eyes, because it's no secret that what's at stake here is more than just a partnership.

If anything happens to Castle, she doesn't think she'll be able to come back from it. Not again.

"Kate."

Both Beckett and Esposito turn at Lanie's call. The ME gives her a sympathetic look that has her stomach churning as she motions her back into the conference room housing the computer screen she can no longer see her partner on.

"I need to show you something."

The only official reason she should be in the hospital is to take Jared Stone's confession, but Esposito shakes his head at her on the way to the man's room, tells her to go find writer boy while he gets the truth from their suicide bomber who nearly infected the entire city.

Beckett uses the privileges of her badge without shame to find him in the hospital, having a reluctant nurse lead her through the maze of hallways until she's being shown to his room. He's no longer in isolation, cleared of any risk for the virus according to the woman holding his charts, and it's officially safe for him to interact with others. So when Kate finally sees him, she doesn't hesitate in throwing her arms around him, burying her face in his neck to muffle her cry of relief.

Castle chuckles, practically lifts her feet from the ground as he smiles wide against her cheek.

"Hey," he whispers, breathless and crushing her to his chest, splaying his palms at her back and tightening the arms around her. "I was just about to come find you at the precinct."

"I couldn't wait," she croaks, pressing her lips to his ear, feeling him go stiff beneath her.

"We need to talk," he sighs, his arms going slack around her body, and she coils her fingers in the front of his shirt before he can step away from her.

"We do, but you promised me something else that I want to hear first," she reminds him, trying to ignore the swarm of nerves consuming her insides like angry bees in the hive of her ribs.

Realization seems to strike him then, his cheeks flushing a subtle pink, and he directs his eyes to the ground. For a second, she's afraid he's going to take it back, claim it was all heat of the moment, just like it was last time, but his lips don't form around any words of argument, and that hope she felt earlier this morning when she learned he was coming to the precinct resumes its tentative revival in her chest.

"Say it again," she murmurs, watching his eyes flash back to her, widening in a moment of surprise before they soften, the calming shade of cerulean already filing with the words he has yet to speak. "C'mon Castle, third time's the charm."

He barks out a laugh, startled amusement blooming along the tired lines of his face, and she places her palms at his jaw, stretches her fingers so that they can span out and brush along the skin of his cheeks. She's always found him beautiful for a man, but he's looked worn lately, ragged with whatever wound she had unknowingly inflicted upon him, but the fatigue seems to fade before her eyes, disintegrating beneath her touch, and she smiles when he leans in, resting his forehead to hers.

"I love you, Kate," he whispers, curling his hands at her hips. "And it's okay if you don't feel the same, I-"

She jerks back, the serenity of the moment coming to a jarring halt, and she stares up at him in confusion.

"What are you talking about?" she asks, searching his eyes, feeling her heart clench with brief panic at the sight of them growing dim once more. "Why would you think I didn't feel the same?"

Hope – the same kind thrashing against the cage of her ribs – flares like a blue flame in the dulled irises and she latches onto that, plows ahead before he can even give her an answer.

"I thought you knew - I thought we were both on the same page, but… god, Castle, I'm so sorry," she sighs, lowering her hands to clutch at his biceps, trying to keep him, to make him stay even as he remains planted to the ground with no move of going anywhere. "I love you too and I'm sorry you doubted it, I'm sorry I didn't-"

His mouth staunches the rest of her apology, his tongue slicking along her bottom lip wiping the remnants of doubt and uncertainty from her mind, and she moans quietly, returns her hands to his face, threading one through his hair to pull him in closer while the other caresses his jaw.

"Don't be sorry," he pants against her lips a second later, peppering a kiss to the corner of her mouth, migrating along to the bone of her cheek, down to the sensitive patch of skin beneath her jaw, trails of heat igniting under his every touch-

"So this must be Kate."

They nearly jump apart, but Castle's arm remains firm around her waist, not giving her much choice but to turn in his embrace to meet the amused eyes of the woman she remembers from the video feed with him. The transit cop who played a huge role in keeping him alive.

"Marisa, hi," he says, loosening his arm around Kate a bit sheepishly, allowing her the opportunity to step from beside him and offer her hand to the woman.

"Detective Beckett, nice to meet you."

The fellow officer takes her outstretched hand, gives it a firm shake. "Likewise."

"How did you know about her?" Castle questions, tilting his head to the side in curiosity as he glances between the two women.

"On my last tour, an IED blew out my eardrum. I got pretty good at reading lips," Marisa explains with a shrug. "You were saying her name before you took down Stone."

Kate flicks her gaze to him over her shoulder, her heart swelling while he rubs at the back of his neck in faint embarrassment.

"Who a person thinks of in that moment has weight, so I figured this Kate must have been pretty special." A hint of a grin tugs at Marisa's lips. "I have to get home to my son, but it was… interesting working with you, Mr. Castle."

"Ditto," Castle answers, but before Marisa can disappear down the hallway, Kate calls her name, catches the woman's attention to say just one more thing.

"Thank you, for having his back in there."

"No need. Maybe just spread the word to your fellow gold shields that us transit cops are more useful than we look," Marisa mentions and Kate nods, offering the woman one final smile before spinning to find Castle waiting behind her. Always waiting.

"Daydreaming about me in your final moments?" she teases, grinning at his exaggerated shrug.

"Are you really surprised?" he murmurs as she laces her arms around his neck.

They've never touched like this, never so freely or uninhibited, and after the events of the past week, after she thought he had finally given up on her, she doesn't want to let him go for a single second. He seems to share the sentiment, bracketing her waist with his broad palms, circling her hips with his thumbs, and she hopes she's allowed to continue touching him like this. Maybe even take the contact to a deeper level and love him in a way she knows he won't misunderstand.

"Come home with me," he presses the words into her hair. "Have dinner with me, we'll talk, about everything, and then…"

She swallows, a dizzying mixture of nerves and excitement flooding through her bloodstream. "And then?"

"Whatever you want," he whispers, nudging his nose against her jaw, resting his cheek to hers. "Anything you want, Kate."

"You," she answers, probably a little too quickly, but it's all she wants, all she's wanted for a long time. Castle pulls back enough to see her, to cradle her face in his engulfing hands. "I just want you."

The kiss he smudges to her mouth is hard but fleeting, leaving her chasing after him for more, but when he tears his lips away from hers, she knows it's because anything more and they'd likely end up doing something highly inappropriate in this hospital room. And she doesn't want that, she wants him slow and thorough in the intimate privacy of his bedroom that she's yet to explore.

The thought alone has her giddy with anticipation.

Kate untangles her arms from his neck and finds his hand, letting him twine their fingers, her slim digits appearing tiny when encompassed by his, and she smiles at the sight while she tugs him towards the open doorway.

"Take me home, Castle."

He drops another kiss to her temple as they make their way towards the lobby, the glass doors that open out to the chilled midday air, and while they wait together on the sidewalk for a cab – after he has the audacity to make a joke about taking the subway – he squeezes her hand and catches her eyes, no longer hiding his love for her behind a veneer of indifference.

"We're definitely on the same page again."