Title: Undeniable
Category: TV Shows » Castle
Author: caskettinacastle
Language: English, Rating: Rated: M
Genre: Drama, Angst, Suspense

Disclaimer: Castle belongs to Andrew Marlowe. This is just me writing for the heck of it. (I'm not making any profit from it. I promise!)

Spoilers: Through end of Season 4.

Chapter One: Rated T (for possible graphic sexual situations)

A/N?: So this is part one of what will most likely be a two chapter story. I wanted to do something that involved Caskett actually being together, and this is just something I envisioned. It probably won't be like what happens on the show, but that's why this is fiction. I really tried to be true to the characters, and I hope that you like it. I want to clarify that part one is actually only rated T, but I wanted to give it a higher rating in case part two is a little more on the graphic side.

"You're so beautiful." The breathless words that Kate had longed to hear for so long, had a surprising effect as Castle's warm breath ghosted over the skin on her neck, sending a shiver rocketing down her spine. Kate squeezed her eyes shut, letting her head drop back onto the pillow as a quavering breath fell from her parted lips. Kate wanted nothing more than to sink into the pillows. She could hardly think straight as Castle's hands continued in their quest over her body, slipping beneath the fabric of her shirt. Kate moaned, as her body became wrought with a slew of overwhelming sensations. Castle's lips and fingers seemed to be lighting her on fire, and she couldn't seem to fight it. Kate bit down hard on her lips, stifling her cries as Castle's fingers started to etch patterns into her skin.

"C-Castle," Kate finally managed as Castle started to push the damp fabric up her midriff. Moments ago she had been cold and wet in his doorway. Now she was warm. So very warm.

When Castle had opened the door, and had gazed at her with those blue eyes of his. She knew she had made the right decision. She didn't want to wait anymore. Her father had said that he'd wasted several years before he finally figured out just how completely he loved her mother. And Kate could still see the sadness in his eyes from time to time. She knew her father regretted wasting so much time, and also knew that he would probably give anything to have those years back. Jim Beckett would have given everything to spend so much as a single moment with Joanna Beckett. And Kate completely understood. For the first time in her life, she knew exactly how it felt, Because Kate Beckett felt the exact same way about Richard Castle.

Their love story had been years in the making. And she still didn't really know how, but over the years, Castle had progressed from a playboy mystery writer, to a friend, to a partner, to a man that she knew loved her so completely. And as much as she wanted to be angry with Castle... as much as she wanted to be angry with him for blatantly concealing important evidence about her mother's case from her, she couldn't hate him. Because Castle loved her. He loved her enough that he didn't care if she hated him for it, just so long as it meant that she was still alive, still breathing.

Kate had spent a lot of time in the cemetery, trying desperately to come to terms with what had happened, not only to her mother, but to herself. As the sky opened up and started to dump rain on her, she tried to remember all of the things her mother had taught her. In many ways she wished that her mother were still there to give her the wisdom she so desperately needed. Because she never knew what to do. She was always torn between her heart, and her duty to get justice for her mother's murder.

He was getting too close. It was what she wanted, and yet, it terrified her more than anything. Castle already was in possession of her heart. Somehow, he'd wriggled his way in further than she'd ever thought possible. But as Kate thought of just how far, she couldn't bear it.

She could feel his lips on her neck; her pulse was starting to race out of control. She was in his bed, his body hovering over hers. And she couldn't breathe. She couldn't breathe because she was so very overwhelmed by the feel of his hands on her. She'd waited for this moment for so long… forever it seemed. And all she wanted now, was to just take it all in. It was crazy how something years in the making could happen so very fast. She didn't want to miss anything. Kate moaned as her body responded to him. She fought it, squeezing her eyes shut as she tried to memorize all of the sensations he was giving her. Castle's lips felt so good on her skin. His hands felt so right clasped around her hips. She could feel the warmth radiating from his body. She could feel his heart beat under her fingertips.

"Cas-" her breath hitched. And though it was barely more than a whisper, she could still hear the plea in it. "Castle, wait. Please!"

"Hmm?" the low rumble of Castle's voice in her ear, along with the warm breath ghosting along her cool skin, had her body writhing underneath him. Kate took a deep breath, and then reached down to stop the progress of Castle's hands. He was keeping her from coherent thought, and she needed to think. Castle, sensing something was wrong, immediately pulled away with his eyes full of concern. "What is it, Kate?" Kate could tell that Castle already thought he had done something wrong.

"I-I'm sorry," the flush of embarrassment on Kate's cheeks grew darker as she pulled away. "I'm sorry. I just. This is all happening so fast."

She felt Castle pull away, looking as if he felt guilty.

"I'm sorry," he apologized, meeting her eyes. "I just… I thought that this was what you wanted. God, I can be such a…" Kate silenced him.

"It's not your fault," Kate breathed. "Cas- Rick, I…I do want this. It's just… It's happening so fast and I don't want to miss anything and I…"

"Okay," Castle noded softly in understanding, his eyes never leaving hers. "It's okay, Kate. We… we don't have to do this." Kate stared back into the eyes of a man she loved and trusted more than anyone else. His sapphire blue eyes twinkled in the dim light. She could see the pain and rejection in them, although she knew that he was doing his best to conceal it. "How about we just curl up for a little while and take a nap?" Castle suggested finally. "Sex is overrated anyways," he added with a twitch of a comforting smile.

"That's not true," Kate replied with a mischievous glint in her eyes before she realized what Castle had been trying to do.

"No. It's not," Castle replied with amusement. "I was just…"

"Trying to make me feel better," Kate finished for him, with a soft kiss to his lips. "Yeah. I know." Kate couldn't stop the sigh that came from her lips as she saw a tinge of regret shine through in Castle's eyes. Feeling the need to reassure him, she slowly reached out for his hand, twining their fingers together. "Castle, I…"

"It's okay," Castle interjected softly. "Kate, you don't have to explain. Really. It's okay." Kate just shook her head.

"But I want to explain," Kate persisted. "Because I know you and I know what you're probably thinking right now. And it's not. It's not you that's the problem. It's me." Castle swallowed, trying to find the right words. "I meant what I said when we started this, when I kissed you. Castle, I love you."

"I know that," Castle smiled, while reaching out to caress Kate's face. She felt her cheek burn against his palm, and squeezed her eyes shut. Kate ceased to breathe as Castle knelt forwards, nuzzling her ever so gently. She knew it was his way of showing affection. She held him close, breathing him in. Kate felt her heart being to sputter in her chest. It had been beating wildly for what already seemed like an eternity. From the very first touches, her body had been aching for him. Now she was with him, and her own fears and insecurities were keeping her from the one thing she'd been waiting for so long. It seemed ridiculous really, but she just couldn't help it. "I meant what I said too. I love you too, Kate." Castle's warm voice confessed. "I always will."

"You've been so patient," Kate found herself saying. "and wonderful. I… I can't even begin to tell you just how much." Kate's throat felt constricted as she thought about Castle and the way he'd always been there for her over the last couple months. Sure, for a while between them, things had been about as bad as they come. But somehow, they'd made it through together, their relationship in tact. And it seemed as if they were all the better for it. Once Castle understood just how much work Kate had been putting into her recovery, he had felt like a complete ass. From then on, he had been patient. Whenever she'd needed him, whether she was able to admit it or not, Castle had been there for her.

'You're not alone in this,' the words echoed in Kate's head as surely as if he'd just spoken them. She'd remember the calmness she'd felt then as he'd taken her hand in his. She knew he meant it.

"I never would have made it through the last year without you," Kate spoke aloud.

"Katie," Castle smiled, touched by the gravity of the emotion in her voice. "I… I hope you know that I would do anything for you by now."

"I do," Kate reassured him. "Rick, I'm sorry."

"Please," Castle looked slightly frustrated, "Stop apologizing. It's okay. We both know that we love each other. That's all I need." Castle swallowed, "There's no need to rush into this." Kate felt her heart swell. "At this point, it's my goal to spend every minute of my time being in love with you. The other stuff can wait."

"God, I love you so much," Kate breathed, pulling him in for a passionate and expressive kiss. Kate moaned as Castle's hands moved over her stomach. When he pulled away, she followed him, pressing her body against his.

"Kate," Castle spoke breathlessly. Kate moaned again, her body and mind so full of want that she could not seem to bear it. "We should slow down. No rush, remember?"

"But God, I want to," Kate confessed into Castle's ear, her hand in his hair. "I want this so much…" Castle pulled away, thinking that Kate might be playing with him. When he met her eyes and saw the desire in them, he knew she wasn't playing. He finally understood. She was torn. Maybe she was right. Maybe he had been moving too quickly. Maybe if he just slowed down a little bit, then they could both get what they needed so desperately.

"You sure?" Castle asked with slight bewilderment.

"Yes," Kate replied honestly. Castle swallowed, then kissed her again. Kate kissed him back, providing more contact. A moan escaped from her mouth as Castle's tongue reached out to tangle with hers. She encouraged the contact and Castle ran his hands under her shirt, grazing Kate's stomach. He started to push up the fabric again and Kate broke the kiss.

"Wait," Kate whispered, halting his progress once more. Castle opened his mouth to ask what was wrong, but Kate didn't let him get that far. "Lights. Get the lights."

"Why?" Castle groaned, pulling away once more. "Kate, I want to be able to see you."

"Please," Kate begged.

"Hey," Castle asked softly. "What's really going on? Why don't you want me to…?" Castle stopped as the thought occurred to him. "Wait a minute. Is this about the scar? You don't want me to see it?"

"It's so angry and red and hideous," Kate breathed. "Rick, I hate it so much. I look at it and I wish more than anything that it would go away, or that it wasn't there at all."

"Kate," Rick silenced her with a finger to her lips. "I understand. Believe me, I do. It must be hard to have to carry that around with you. To look at it and know why it's there and what you've been through. I don't blame you for wanting it to go away."

"You have no idea," Kate groaned softly, with tears building in her eyes. "I hate it."

"I know you do," Castle replied, "But I don't."

"What?" Kate's eyes flashed in confusion as she bit down on her bottom lip. Castle knew that he would have to explain himself.

"Don't get me wrong," Rick corrected himself. "I would do anything to go back in time and spare you from what happened. After all, it's my fault that it's there."

"I told you to stop blaming yourself for that," Kate interjected. "Rick, it's not your fault."

"Yes it is," he argued, his voice thick with emotion. "Look, what I'm trying to say is that I wish I could go back in time and stop everything from happening. At the same time, I know that I can't do that. So I have to accept that scar for what it is." Castle paused. "And I've realized that the more I think about it, the more that I can appreciate it." He decided to try and explain it.

"I'm a writer, Kate," Rick swallowed. "You may think it's crazy, but I don't think that scar is something to be ashamed of."

"Why not?"

"Because, I just can't." Castle sighed. "You know how I told you that everything has a story?"

"Yes. I remember it quite well," Kate replied. "It was during our first case."

"Well," Castle swallowed. "That's why. I think it's important, because it tells a story. It's hard for you to look at it from the other side, because you are the one it affects directly. But for those who care about you, they see it differently. You probably look at that scar and remember what happened to you. You flash back to the moment everything happened. You think about the horrifying moments afterwards, and the surgery, and all of that rehabilitation. In that way, you're forced to always carry that around with you. It is a constant reminder of that morning in April." He paused. "Yet, at the same time, that scar is the only physical proof remaining that anything ever happened to you. You can cover it up with clothes and no one would be the wiser. They wouldn't know it was there. You know the story since you lived through it, but not many other people do. Someone who doesn't know what you've been through would look at that scar and see just scar tissue. I know that you don't like to share very much, but to someone who knows you? Someone who knows what you've been through? That scar is beautiful. It is so beautiful because it is a testament to your strength, your resilience, and who you are as a person. You beat the odds. You fought through the pain and didn't give up when 90 percent of others would have. That scar is a testament to you and your personality and it proves you are extraordinary. Kate, you are the most beautiful woman I've ever been graced to lay my eyes on, and nothing… nothing can ever change that… especially not a tiny red scar."

"Only you could make something awful sound like a good thing," Kate breathed, her breathing hitching ever so slightly as he ran his hands over her stomach.

"It's the romantic in me," Castle offered, gazing into the depths of her eyes. He felt her hands pull him closer.

"Okay…" Kate conceded finally. "But don't say I didn't warn you." Castle sighed, torn with indecision as Kate squeezed her eyes shut. It was like she was bracing herself for his touch. Castle's heart clenched painfully in his chest as he observed Kate's discomfort. He paused for a long moment, deciding that he needed to reassure her more. Slowly Castle bent forwards replacing the touch of his hands with his lips. He kissed the skin above her naval and slowly started to kiss his way up her abdomen, while his hands slowly pushed up her shirt. He could see her brows furrow as she lay completely still. When the fabric caught on Kate's arms, she lifted her upper body mechanically, allowing Castle to slide the garment up and over her head. She heard Castle's labored breathing and realized that he was afraid of doing something wrong. She opened her eyes to find him gently running his hands over the small puckered depression that marred her otherwise flawless skin. He traced it with his fingertips, and surprisingly she felt warmth spread from the touch. It didn't hurt like she thought it might, but she suddenly was having difficulty keeping her breathing even. Something about the way he touched her and the look of wonder and amazement on his features had her heart beating in a sort of staccato rhythm.

"Rick?" Kate's voice broke his name into two exhalations.

"Of all that happened to you," he nearly whispered, "This is the only thing that's left…"

"Hey," Kate reached down to his hand, stilling his hand. Suddenly, Castle was launched from his reverie. She gasped slightly as he lifted his eyes from her chest and met her eyes. She felt a swell of emotions as she realized that there were tears in them. Castle… Castle was crying. "Hey," Kate pleaded, reaching up to caress his cheek. "Don't do that. Don't get emotional on me, or else I'm gonna," Kate's voice trailed off as she realized she was already following in his wake. Her vision blurred as moisture built in her eyes, making it feel like they were burning. Her throat was tight as she struggled to hold them back.

"I'm sorry," Castle apologized, "I'm really sorry. I didn't mean to react this way, but I…" Castle's voice broke. "I never realized just how much of an effect seeing it would have on me. I remember everything that happened so clearly. I… I think about that day and I feel all of the emotions start to come rushing back… I honestly thought that I was going to lose you. And no matter how many times you tell me what you went through that day wasn't my fault, I know it was. If I had never reopened your mother's case then…." "

"Then I would have," Kate cut him off. "It might have taken me a bit longer. But my mother's case was never far from my heart. You know that. And you… you know me. You know that I never quit. You can't… You can't blame yourself, Rick. You weren't the one holding the gun. You've never done anything to hurt me. In fact… you've done just the opposition. You've always given everything you possibly could to protect me."

"But it wasn't enough," Rick spoke. "I couldn't protect you. Not from the bullet. Not from everything that came after."

"No," Kate shook her head. "It was enough. Castle, I should be grateful to you for giving me something to fight for. I could say that your words didn't factor into things, but in the end, I know it did. Because I finally knew how you felt. I knew that I loved you. And when I saw the life that we could have together and I realized just how much I would give to see those days, it made me fight harder to take down that wall. To put everything behind me.."

"I don't want to lose you," Castle confessed, kissing the inside of Kate's palm as he closed his eyes. "I can't… I can't ever lose you. I wouldn't know how to be me without you." Castle nearly scoffed at his own words when he realized how clichéd they sounded, but it was how he felt. "I don't know how, but somehow, over the last couple years I've come to expect you would always be there to call me out on all of the crap I pull. I know it sounds cheesy, but it's true. I… I need you."

"You make it sound like I'm going somewhere," Kate said lightly, trying to lift some of the tension from the conversation. "Rick," Kate breathed tensely, "I know that you still don't believe me sometimes, but I'm here. I'm fine. And I'm not going anywhere. Not anytime soon."

"But the shooter is still out there and…" Kate silenced him.

"And there isn't a place that they can run. Not from you or me, or Ryan, or Esposito. We're going to catch the son of a gun who did this. I know because I can see the fury in your eyes. And as strange as it sounds, I find that comforting. Because I know that you won't ever let anything happen to me."

"I love you so much," Castle breathed.

"I know," Kate breathed back, running her thumb over Castle's lip. Castle's eyes slowly wedged there way back open. He was surprised to find Kate still lying flush underneath him. Carefully she reached up and tugged him down against her. Her lips took his in a kiss and he lost himself in her. "I love you too," she breathed as she ended it. She sighed contentedly as he carefully kissed his way down to the hollow behind her ear. He paused there for a moment before kissing his way down her neck to her collarbone and then down to the place above her sternum. She gasped as he reached his destination; placing feather light kisses over the swollen tissue. With a whisper barely loud enough to be heard, Kate felt herself coming undone from the inside out. She couldn't hold back anymore. She wanted Castle, all of him.

"Beautiful," he breathed over and over. "So beautiful." He looked up and caught her eyes staring back at him. She had never been so sure of anything in her life, as she was in this moment. She knew was safe in Castle's arms.

A/N: So that's part one! Part two will probably be a little more intense. Please take a moment to hit the review button and say a few words. It really means a lot to the author when we get some feedback! :)