Author's Note: This epilogue ended up being more angsty than originally planned but it does end happily, which I hope makes up for it. Takes place during "3XK."

What the Heart Wants

Epilogue

Kate couldn't breathe. An iron fist seemed to have reached into her chest and grasped her lungs, her heart, so she couldn't draw in a breath.

She was gripping the steering wheel of her car so tightly her hands hurt but she didn't care, welcomed the discomfort if anything, because she deserved it. She deserved every bit of pain and worry she was feeling right now and she thought she might never forgive herself.

What had she been thinking, doing? She'd been hiding, holding back from the last surrender of her heart. Even if she had admitted to herself that she was in love with Castle, she hadn't told him that. She'd kept it to herself, maybe not deliberately, but she had. She'd been trying and she was getting better at being open about this kind of thing with Castle, talking to him more, but she hadn't been able to tell him in so many words that she loved him. It had seemed too… big an admission, exposed so much vulnerability.

Why hadn't she told him? Had she thought that not admitting it out loud would somehow protect her, make Castle mean less to her? Keep her from being quite so committed to this relationship?

It was so stupid, so useless, and now, she was paying for her stupidity as if for a crime. Because now, she was faced with the terrible dread that Castle was in danger, hurt, and he didn't know that she loved him. And she might have lost the chance to tell him.

Oh god, no! She couldn't lose him, she couldn't. Not now, not ever.

Kate savagely blinked back the tears that would keep trying to well up in her eyes, blinding her, and vowed to herself, to whatever higher powers there might be, that if Castle was okay, if she saw Castle again, she would tell him that she loved him and then she would spend the rest of her life making sure he knew, without any doubt, that she loved him just as much as he loved her.

Because he did love her. She knew it but then, he had told her he loved her. He wasn't as much of a coward as she was.

She choked back another sob at the thought, the memory.

His voice had sounded strange, stilted, when he had answered his phone earlier, sending her heart plummeting even lower into the pit of her stomach. He had said he was fine but he'd said it as if he were reading from a script and by now, she knew his tone, could almost always read his mood from his voice.

And then he'd said it. "Katherine, I can't talk right now but I love you, okay?"

Stupidly, her first thought had been that he never called her Katherine. He'd called her Katie a couple times to tease her, after he'd heard her dad call her Katie, and she had retaliated by calling him Ricky in a simpering tone that made him grimace. But he never called her Katherine.

Her second thought had been that it was the first time he'd said the words to her outside the privacy of a bedroom and for once, she'd thought frantically that she didn't want to hear it, didn't want him to say it. Not now, not when they were tainted with burgeoning panic, not when she couldn't see him. He hadn't said the words often, only a few precious times, and the first time, she wasn't even sure she'd been meant to hear it because he'd mumbled, "Love you," when they were both drifting to sleep. He'd said the words again, and then again, when they were both more alert and awake and both times, she'd only been able to respond with a kiss, hoping that her kiss would make up for the words she couldn't quite say.

She'd choked. "Rick…"

She'd been close, so close, in her newfound terror, the words, I love you too, had been on the edge of her lips but then before she'd managed to squeeze them past the lump in her throat, he had cut her off, saying he needed to go and would see her later.

And she'd known, with bone-deep certainty, that something was very wrong. In all the hundreds of phone calls she and Castle had exchanged over the last few months, even before they'd gotten together, he had never, ever cut her off like that. Unless he absolutely had to, he never cut her off. And he was almost never the one to suggest they end their conversation either, was usually the one to linger on the line until she teased him and they mutually agreed to hang up on the count of three.

If he was cutting their call short, something had to be wrong. It wasn't evidence anyone else would accept—she wouldn't accept it in any other situation—but she knew Castle.

She couldn't decide if she was a little relieved that he had cut her off before she could say the words to him. She didn't want the first time she said the words to be so tainted with panic but then again, if anything happened to him, if that call had been the last time she talked to him, she would never ever forgive herself knowing that he hadn't known, she hadn't told him when she should have.

Oh god, she should have told him every day, every minute of every day, that she loved him. She, of all people, knew that nobody's tomorrows were guaranteed.

But she hadn't and now Castle might— She cut off the thought before the terrible word could even form.

It wasn't a long way—thank god—to get to the motel where Jerry Tyson had been staying but every second seemed to drag, even as she simultaneously, irrationally felt that time was racing, speeding up in time with her frantically rabbiting heart. A ticking clock that seemed to speed up as it neared the end of the countdown…

No, no, it wasn't the end, could not be the end. She couldn't believe it. Couldn't let herself believe it.

She had no clear memory of driving, thought it a minor miracle afterwards that she hadn't gotten into an accident with her complete disregard for her own safety and every traffic rule under the sun. She hadn't had any corner of her mind left to think about such mundane details as traffic rules, had only switched on her siren and sped.

As it was, she was later surprised to find that she even remembered to turn off the ignition to her car before she flung herself out of the car and sprinted towards the motel, the room that had been assigned to Tyson.

Her heart was pounding so loudly it made her deaf to anything else and she almost skidded to a halt, almost running past the door in her haste, and kicking it open. She knew Espo was on her heels but she couldn't wait.

"Castle!"

"Beckett! Room's clear; he's gone. I'm fine."

The beam of her flashlight found him, squinting in the glare, but alive—blessedly, wonderfully alive. The rush of relief made her dizzy and she staggered across the room on legs that suddenly felt wobbly beneath her, falling on her knees in front of him.

She was only peripherally aware of hearing Ryan groan and start to stir on the floor and some corner of her mind processed relief that Ryan was alive too but she wasn't fully conscious of it. Her conscious mind was focused only on Castle.

Her hands skimmed over his thighs, his stomach, his side, his chest, needing more than just a visual reassurance that he was alive, unhurt, needing the physical touch. A choked sob escaped her as she completed her survey and then she belatedly realized she should untie him. Her fingers were trembling and uncoordinated so she fumbled but finally, eventually, the knots gave way and then Castle's arms were wrapping around her, tugging her up against his chest.

He was chanting her name, murmuring it against her hair, as if he'd never thought he would be able to say it again. Her name mixed in with other things, that he was all right, that he was here, that they were fine, a litany of reassuring nothings that still meant everything.

She buried her face in his shoulder, shutting her eyes against the sting of tears, and drew in what felt like the first full breath in hours, even days. She breathed in his scent, one she knew so well after these last few months, the scent that lingered in his sheets and on his clothes, some combination of his body wash, his after shave, his laundry detergent, and underlying it all, the scent that belonged solely to him. The scent of home—and it slowly unlocked her muscles.

She had no idea how much time passed before she managed to bring herself to release him, drawing back enough to meet his eyes, loving the sight of them, so bright and blue and filled with life and light and, yes, love.

"Beckett, Tyson did it. He's 3XK. Gates was just a copycat," Castle told her with belated urgency.

She nodded. "I know; I figured that out when you and Ryan didn't come back and then Martha called and then when we talked, you sounded weird on the phone."

He managed a faint, tired quirk of his lips. "Weirder than usual, you mean." It was the sort of joke he would normally make but for once, it fell flat and instead of a laugh, she choked on the beginnings of another sob instead.

"Castle—"

He reached up and swiped a gentle thumb over her cheek, wiping away the tear that must have escaped. "Ssh, I'm sorry, Kate. I shouldn't have tried to joke about it, I know."

"Castle, glad to see you're okay, man. Hey, Beckett."

Esposito's voice startled Kate into a belated awareness of his presence—and Ryan's, she realized with a spurt of guilt—and at any other time, she might have felt some embarrassment at how completely she'd been focused on Castle, how much she'd revealed about her own feelings in front of the boys, but at the moment, she didn't have the emotional bandwidth left to care about that. She only turned to look at Espo, even as one of her hands closed around Castle's, not wanting to lose any form of contact with him. Espo was standing now and supporting Ryan, who was slouched into him, looking dizzy but otherwise okay. "Yeah? Ryan, you okay?"

"Ryan needs an ambulance," Castle inserted.

"No, I don't," Ryan groaned.

Espo spoke over Ryan, ignoring his partner for once. "SWAT team's here and a bus is on its way. You good to help Castle out of here?"

"I don't need help," Castle protested but subsided as Kate pushed herself to her feet, half-surprised to find that her legs were no longer shaky beneath her, and tugged him to his, immediately sliding her arm around his waist, wordlessly encouraging him to put his arm around her shoulder, which he did.

It wasn't the first time Kate had realized that this position, with his arm over her shoulders, wasn't the most comfortable one for them when she was wearing her heels. They were too closely matched in height when she was in her heels so with his arm around her shoulders, she couldn't stand up straight, needed to slouch uncomfortably. But she didn't care. She wasn't about to let him go and even the marginal distance between their bodies if she only held his hand seemed like too much at the moment.

She felt Castle brush a kiss to hair and in response, nestled closer to him, as they trailed after Espo and Ryan out of the hotel room. Ryan stumbled a little, seeming to sway, and if it hadn't been for Espo's quick reflexes, might have fallen but Espo caught him and then supported him as they made their way out of the room and down the stairs to the parking lot.

With Ryan as apparently concussed as he was, their progress was slow and halting and for once, Kate didn't feel even a flicker of impatience, was content enough to linger behind. She took advantage of one of Ryan's pauses to steady himself to brush her lips against Castle's chin, the only spot she could easily reach. His hand briefly squeezed her arm a little tighter at that and she resettled her grip on him too.

By the time their slow procession had reached the parking lot, the SWAT team was dispersed, cops swarming over every inch of the motel, in a belated search, and the ambulance had arrived. EMT's quickly took over, getting Ryan onto a stretcher, disregarding his feeble protests that he could walk, and ushering Castle to the ambulance to check him over too.

With Castle safely in the hands of the EMT's, Kate belatedly remembered that she should call Martha and let her know that Castle had been found, was safe, and slipped away to make the call, allaying Martha's frantic questions. Kate's heart pinched a little. She hadn't needed this to tell her that the barbs that flew between Castle and Martha were a mask to hide the real depth of their relationship but it was a stark reminder. She assured Martha again and again that Castle was fine, unhurt, mentioning his protest on even being checked by the EMT's as proof, and promised she and Castle would be home soon.

With Martha somewhat restored to calm, Kate ended the call and on impulse, crossed the motel lobby to the coffee machine in the corner. It would be cheap motel-quality coffee, of course, but it would be hot and, well, it was coffee.

That done, she returned to the parking lot, to the ambulance where Ryan still was, with Espo and now, Captain Montgomery, hovering just outside.

She caught up to them to hear the tail end of Ryan's brief update to Montgomery. "—who guessed. Then Tyson got the drop on me, knocked me out with my own gun." He made a face of scorn, directed at himself. "Like some rookie. And Tyson got away because I wasn't fast enough."

"Hey, don't beat yourself up, bro," Espo spoke up.

"He's right," Montgomery chimed in. "Tyson fooled everyone, including me, all those years ago, so it's not on you." He sighed, abruptly looking tired and older than his years, before he straightened up, all business again. "You can give your official statement tomorrow at the precinct, Detective. In the meantime, you're going to the hospital, make sure you don't have anything more than a mild concussion."

"But sir—" Ryan started to protest.

Montgomery ignored him, turning to Esposito. "Esposito, you make sure he goes to the hospital and then make sure he gets home, if they release him."

Espo nodded. "Yes, sir."

Now Montgomery turned to Kate. "Beckett, I told Castle he can give his official statement tomorrow too. Go home and take the morning off, both of you. I'll see you in the precinct in the afternoon."

For once, Kate didn't protest the order to take time off, only nodded, and then felt a quick spike of worry as she registered that Castle had left, was no longer standing a few steps off. It was irrational, she knew that, since with the motel still crawling with cops, it was probably the safest place in the city right now, but she still panicked when she didn't immediately see him. "Where'd Castle go?"

She was aware of the betraying quiver of fear in her voice but couldn't help it. Anyway, it wasn't as if Montgomery and the boys weren't perfectly aware of her relationship with Castle.

They glanced around and it was Espo who spotted him, pointing out his familiar shadowed form, sitting on a bench by the pool on the other side of the parking lot. The one place that was removed from the bustle of law enforcement. "There. Guess he needed some space."

Kate tried to flash Espo a smile of thanks but couldn't force her facial muscles to cooperate before she turned and headed towards Castle without another word.

As she neared, she registered his stance, the way he was hunched over, his elbows resting on his knees, as he stared at the pale blue light flickering from the surface of the pool. That hand was back, seemed to be squeezing her heart again, at the sight. Because that wasn't right, wasn't like Castle. Her Castle, the man she knew and loved, was happy, an incurable optimist, not this bleak figure who looked over-burdened, bearing the weight of the world.

"Hey" she greeted him quietly as she joined him on the bench. "I brought you coffee."

For the first time in her memory, the offer of coffee didn't elicit a smile, or even an answering spark in his eyes, as he accepted the cup. All he did, although it was enough to reassure her that her company wasn't unwelcome, was grasp her hand with his free one, gripping it firmly.

He didn't speak, the silence not very like him, although by now, Kate knew that Castle occasionally had his brooding moments when he needed to be prodded into sharing. They had turned out to be somewhat more alike in their reticence than she had expected, although he was naturally more open than she was, even with her efforts.

After a moment, she ventured, "I called Martha, told her you were all right. And Alexis is asleep; Martha didn't tell her anything."

He released a breath. "Thanks." The word was quiet, just above a breath.

There was another silence, this one lasting long enough to make Kate feel uncertain, concerned. No, this wasn't like Castle. Now that her overpowering relief at finding him alive and unharmed had subsided into a sort of tired calm, other more nebulous fears were creeping in.

Of what, she wasn't even sure. But finally, she asked, partly because she wanted to know and partly just to nudge him into saying something, "Why did he let you live?" She bit her lip the moment she asked it, realizing it sounded wrong, put like that, but she wasn't sure how else to phrase it either.

He sighed heavily and slumped yet more, leaning into her. "To punish me." He paused, swallowing, before going on, not quite steadily, "Make me pay for ruining his plan. Now he's going to kill again, all because I couldn't stop him. Because I failed…"

He sounded so… despondent, so guilty, and that iron fist was back, crushing her lungs, her heart, in a vise.

This was because of her. The thought flared through her mind, seemed to be seared onto her brain like a brand.

She had always wondered, feared, that she couldn't—wouldn't—in the long run be good for Castle, make him happy. How could she, with all her issues, her life that revolved around death and darkness, actually be good for him, who was so good at making people happy, brightening people's lives?

And now she knew. She couldn't. That was her burden.

She might know that his interest in murder and the macabre was not new, had predated his meeting her by years, but this personal burden of guilt, the sort that ate away at a person's spirit, this was new for him. It was part of the burden of being a cop, what every cop accepted with the badge, but Castle was not a cop, had not accepted the burden. He was here because of her and now, because of her, he would be haunted.

She flinched sharply at the thought, the words hitting her like a blow, and released his hand. She couldn't draw in a breath, the very air she inhaled felt jagged and sharp against her throat and lungs.

"Kate? What is it?"

She choked down the sob building in her throat. "I'm sorry." The words came out like a croak and she had to swallow, hard, before she could go on. "I'm so sorry."

"For what?"

He was going to make her say it. (Of course he was. Castle was too kind, too generous, to acknowledge that she might not be good for him.) "Tyson got to you because of me. I'm the one who brought you into this, the reason you were involved with this case."

He jerked upright, staring at her as if she'd suddenly sprouted a second head. "That's insane."

Well, if she'd wanted to prod him out of his torpor, she'd succeeded. "No, it's not. Before we met, you didn't work with police, didn't get involved with criminals. The burden you feel now is because of me."

"No, it isn't. Contrary to popular belief, I am an adult," he clipped out, sounding acerbic rather than humorous as he normally would. "I'm responsible for my own choices and I was the one who chose to follow you." He paused, sighed, his brief flare of irritation seeming to leave him. "You haven't done anything to be sorry for. All you've done, all you do, is make me happy."

Her breath stuttered in her chest. How did he know what to say, what she needed to hear? "I do?" She wanted to believe it, wanted to make him happy, but some part of her doubted if she could. She wasn't like Castle, wasn't very fun or spontaneous anymore, wasn't as effortlessly cheerful as he was.

His expression softened as he reached out and grasped her hand again. "Oh, Kate, you little idiot." Somehow, his tone, his look, transformed the epithet into an endearment of sorts. "How can you not know how happy you make me? Aside from Alexis, no one has ever made me as happy as you do."

"Really?"

He huffed a little but for the first time since she'd found him, managed a wan little smile. "I think I know how I'm feeling."

He was deliberately misinterpreting her question. A strange sound escaped her that was some combination of a sob and the beginnings of a laugh. "Castle."

He released her hand only to cup her cheek, leaning in to touch his forehead to hers. "Remember how I told you on our first date that my life is better with you in it? I meant it and these past few months have just proven it over and over again. There is no way in which my life is not infinitely better because of you, okay?"

Oh damn, he really was going to make her cry, his words easing doubts, fears, she hadn't fully realized how much they'd been lurking inside her. She sniffed and nodded. "Okay."

"Good. Now, no more crazy talk. I'm supposed to be the irrational one in this relationship, remember?"

She choked on a watery laugh. Oh this man, always managing to make her laugh. "Right."

His hand started to leave her cheek but she lifted her hand to hold it in place, keeping him from moving. "Hey, Castle?"

"Hmm?"

"I love you." The words were said in a whisper. It might have seemed a little odd to admit it just after she'd been doubting her effect on his life but now that she was reassured, she couldn't hold the words back any longer. She was in love with him, irrevocably, and now he knew it.

His breath hitched. "Kate…"

"I do. I really love you," she repeated.

He stopped any further protestations with the touch of his lips, pressing a quick kiss to her mouth. "I know you do," he murmured against her mouth. "I love you too."

Now, she managed a shaky smile. "Okay, good."

He kissed her again with more urgency this time only for the kiss to be abruptly broken off at a sharply-truncated blast of a siren, making them both jump and come to the belated awareness that they were still in a public place, in full view of any number of cops.

They exchanged rueful half-smiles. "We should go home," she suggested. "Your mother will be worrying."

He tugged her in to drop a quick kiss on her temple. "That's another thing I love about you, Beckett, how much you care about my family."

She linked her arm with his as they turned to leave the pool area, keeping herself tucked close to his side. "Your family's wonderful."

He tossed out the coffee which he hadn't drunk much of in the trash as they left the pool area. "You're coming home with me?" he asked, almost as if it were any other night since she didn't spend all her nights at the loft.

"I'm not letting you out of my sight," she answered candidly, before she could even think about it.

She'd left her keys in the ignition, she belatedly realized, something she'd never done before. Thankfully, there hadn't been much risk to it because her car had been almost immediately surrounded by other police cars but still, it was evidence of just how distracted she'd been. Evidence which Castle noted, she saw, his expression softening as he flicked a glance at her.

The drive to the loft passed in silence, their hands still joined since Kate didn't want to relinquish the physical connection to him.

As she'd expected, Martha was waiting for them when they entered the loft, immediately flying towards Castle and enveloping him in an embrace of brightly-colored silk. And Kate was somewhat surprised when Martha turned from Castle to her, embracing her in turn and fussing and fretting over Kate in equal measure, as if Kate too had been in danger tonight. Martha kept an arm around each of them as she shepherded them to sit on the couch and peppered them with anxious questions.

Castle gave his mother a highly truncated and sanitized version of the story, telling her very briefly that he'd gotten into a tight spot but he was fine, everything was okay, and there was nothing to worry about.

Martha didn't look entirely convinced but agreed to go to bed at Kate's urging and repeated assurance that they were both fine. She retreated upstairs but not until after she had hugged both Castle and Kate again and kissed their cheeks.

Kate felt warmth bloom in her chest, encompassing her heart. She really was part of this family now, wasn't she?

Castle drew Kate into his arms, pressing a kiss to her temple. "I'm going to go check on Alexis," he murmured against her ear. "Wait for me?"

She nodded, unsurprised, since she knew that Castle still checked on Alexis every night if he wasn't home before she went to bed. Normally, Kate preceded him into their bedroom and started her own nightly ablutions but today, she accompanied him to the foot of the staircase (ridiculously) and then dallied there for the couple minutes it took for Castle to check on Alexis.

On any other day, she knew he would have made some teasing comment about it but then again, on any other day, she wouldn't have done such a thing. Tonight, he didn't tease, only slipped his arm around her as they headed into their bedroom—yes, their bedroom. Not officially, not yet, but it was theirs, their little haven of privacy.

Once inside, she turned into him, wrapping her arms around his waist and burying her face in the curve of his neck.

Castle wrapped his arms around her in turn, one hand rubbing her back in slow, soothing motions. She sank into his embrace and thought, not for the first time, that here, in Castle's arms, was the place where she felt safest.

"I was so scared," she admitted in a mumble against his shirt. "I thought I'd lost you and… I hadn't told you that I love you."

He slid one hand up to cup the back of her head, exerting just enough pressure so she lifted her face to meet his eyes. His eyes, which were so amazingly soft and filled with a tender light that she only ever saw when he was looking at her or at Alexis. "Did you think I didn't know? As much as it means to me to hear the words, I already knew."

She gulped, swallowing back something between a gasp and a sob. "You did?"

He cupped her cheek with his hand, a faint smile tugging on his lips. "I know you, remember? You show me you love me every day, Kate. It's in your smile, your eyes. It's in the way you talk to me." His tone shifted just a little. "It's in the way you touch me."

She flushed. "It is?" she managed, rather feebly. Not because she disagreed or even doubted him but so much for having a poker face. Although, she thought, that it was only to him that she was easily read because with him, she didn't really try to hide her emotions behind her detective mask. She might not always be good at talking openly about her feelings yet but she no longer tried to hide how she felt either.

"You knew I loved you before I told you, didn't you?"

"Well, yes, but I'm a detective. And you're not that subtle."

"I'm a writer; I observe people. And I've practically made a profession out of observing you."

"Creepy," she flipped back. By now, the term had become something of a private endearment between them, a private joke.

"Only with you."

She already knew that but it was still nice to hear. He was hers, just as she was his. "Good."

She rose up to kiss him; they didn't need to talk anymore.

The passion that always seemed to simmer beneath the surface flared up and they gave themselves up to it, their clothes falling away as if by magic. Certainly she had no clear idea of how it happened, her mind entirely taken up with the workings of his mouth and his hands.

By now, she knew every inch of his body, knew exactly how to touch him, how to make him groan and lose control. It was a knowledge she gloried in and used now, communicating with every kiss and caress of her lips and tongue and hands and body that she loved him.

And he did the same, their hands roaming each other's bodies, pleasure the only intent—giving it, receiving it, sharing it. And it was all shared.

Their gazes met and held as their bodies moved together, their breaths mingling in a kiss, and they reached the pinnacle together too as he groaned and she cried out, a cry half-swallowed by his mouth.

She collapsed on top of him, boneless and overwhelmed. This was what really making love felt like. This was the truth of them, what she wanted for the rest of her life.

His arms were draped heavily across her back, holding her in place against him, not that she had any thought of moving anytime soon. She could feel his heart beating against her chest and couldn't distinguish between the rhythm of her heartbeat or his.

She wasn't quite sure how long they lay like that but eventually, they did rearrange themselves more comfortably, until she was lying nestled against his side, her head pillowed on his shoulder and his arm around her.

"Will you be okay?" she murmured quietly.

"Hmm?" he sounded sleepy and she felt a little niggle of guilt. She hadn't realized he was falling asleep.

"Will you be okay, dealing with the guilt?" she explained. She still hated the idea that Castle would feel the burden of responsibility, of guilt, the way she and other cops did.

He was silent for a moment, really thinking about it and not giving her an automatic response. He sighed a little and she felt him brush his lips against her forehead. "I think so. I've got you so I think I'll be fine. You help."

Oh, she hoped so. She wanted to believe that she could somehow make things better for him the same way he did for her. And promised herself she would do whatever she could to make it so.

She turned her head to brush her lips against his chest, settling her arm around him a little more firmly. "I love you," she breathed.

"I love you too, Kate, always."

Warmth settled in her chest and she drifted into sleep with the word, the promise, lingering in her mind. Together, always.

~The End~

A/N 2: Thank you, everyone, who's read, reviewed, followed, or added this story to their favorites. It is all much appreciated. I wish you all very happy holidays!

Until next year and the next story!