Hey all,

So this is one I've written recently, and I know I should be continuing other stories I've uploaded, but this simply would not leave my head. Hence spending a number of sleepless nights finishing it :)

It's based after the very serious argument that Castle and Beckett have in Knockout. Basically, it's something that would not leave my mind, no matter how hard I tried.

I don't own any of the characters or anything, this is just a bit of fun.

Hope you enjoy, reviews are greatly appreciated!

x

Beckett

I lay on my stomach, my head turned to watch the steady glow of the alarm clock. My body was stretched out fully, legs tangled through the sheets from my endless tossing and turning.

The alarm clock flicked over to the next minute.

1:05 am

I heaved an impatient sigh and flipped onto my back, feeling my frustration and anger grow as I mused once again over the reason for my sleeplessness.

Richard Castle.

He continued to haunt my presence all night. I had ordered him to get out, yet it was almost as though he hadn't left at all.

I felt my jaw clench as I recalled his words.

I know you crawled inside your mother's murder and didn't come out.

The first tears began to form behind my eyes as I felt my stomach tie itself into tighter knots.

I know you hid there, the same way you hide in these nowhere relationships with men you don't love.

His voice had been hard, firm. He was never like that with me; his behaviour was always childish and easygoing. But this, this was something different. He was deadly serious and almost getting...angry. My heart began to ache as a single tear fell down my face and into my hair.

That tear opened the floodgate as his final words echoed around my silent apartment.

You could be happy, Kate. You deserve to be happy. But you're afraid.

As the tears began flowing and the anger stirred in my chest I gave in. I scrambled out of bed, threw on a sweater, grabbed my keys and gun and headed out of the door.

Castle

The ice chinked in the bottom of my glass of water as I drained the last of it into my mouth. The affects of the whiskey I had consumed earlier was beginning to wear off, and yet I felt no better.

The hard look on Beckett's face when she had snapped had shattered my heart into what felt like a million shards, each one buried deep inside my chest and causing unimaginable pain.

The pain on her face when I had finally forced her flaws upon her remained burned into my retinas. Every time I closed my eyes, her face flashed before me. I couldn't recall ever feeling so miserable.

I knew that it was over. There was no way she would ever take me back after that argument. I had finally succeeded in bringing up the kiss, but it wasn't in the way that I had hoped.

I knew I had pushed it too far when her jaw clenched. Instantly a wall closed behind her eyes and they became hard and unreadable, much like when I first met her. When she hated me passionately.

I felt the urge to throw the tumbler, but stopped myself at the last minute. Not only did I not want to clean up another broken glass, but if I had to speak to Mother again I was sure to lose my composure and go and find Beckett myself.

Beckett

Somehow I made it through the deserted streets without crashing the car. I knew I wasn't travelling at legal speeds, but for once in my life, I didn't care.

Before I knew it I had parked at Castle's apartments. I wasn't sure what I was going to do once I got there, but I couldn't sit around at home any longer.

I headed in the front door, which was unmanned. It didn't really surprise me, as it was past one thirty in the morning. I got into the elevator and hit the button for Castle's floor.

My heart was pounding in my chest, my breath coming in shallow gasps.

The lift chimed and the doors slid gracefully open, allowing me to step out and walk down the hall.

I came to a halt outside Castle's door and felt my stomach erupt into butterflies as I began to regret coming.

My hand hovered unsteadily, as I raised it to the door. It was then I realized I was trembling from head to toe.

"What are you doing Kate?" I mumbled to myself. "Stupid."

I let my palm rest flat against the door, leaning my head down and realizing how stupid I was. Castle was probably fast asleep at this time, and there was no way I would risk waking up Martha or Alexis.

Just as I was about to drag myself away and go home, the door handle turned.

I jumped a mile high before stepping back to flee to the elevator.

I made it halfway before I heard a shocked exclamation.

"Beckett?"

I winced as his voice stopped me dead in my tracks, my heart pounding in my ears. Slowly I turned around.

Castle was standing at the door, a jacket pulled over his grey shirt and jeans, with his car keys in hand.

"What are you doing here?" He looked shocked and completely confused. "Is everything okay?"

I grimaced, realizing just how much of a fool I looked like.

"Yeah, everything's fine, I'm just going to go..." I turned and practically ran to the elevator.

"Kate! No!" He ran after me, grabbing my arm to stop me. I avoided his gaze, keeping my eyes glued to the floor. "Come in. Please."

Wordlessly, I turned and followed him inside his apartment.

"I was coming to see you. To apologize," he muttered softly when we were standing in his kitchen. "I was stupid to be such an ass to you. I know what this case means. I'm just..."

He trailed off, and I could feel his gaze wander over my body. It was a piercing gaze and it raised all of the hairs on my body.

"I'm just so scared for you."

I continued staring at the floor as the emotions battled each other throughout my body. Anger. Guilt. Remorse. Bitterness. Longing.

And somewhere deep inside, shut away with my nastiest demons, resided the emotion that he had named, the one he had shoved into my face because I was too afraid to bring it out into the light.

Fear.

Damn it Castle.

I felt a tick start in my clenched jaw as I tried my hardest to avoid his stare. His harshest words were once again echoing in my ears

You're afraid.

I felt a sob rise to my lips as I took a deep breath. I pushed it away and tried to hold up some composure.

"I just can't stop. I have to know, and I'll do whatever I have to if it means I find my mother's killer," I said quietly, keeping my eyes on the floor. He took a step closer to me.

"I know, Kate, trust me I understand how much this means to you. No matter what you say, I do know enough about you to know you won't stop until you find whoever killed your mother and either kill him or put him behind bars."

He was so close I could smell his cologne, the smell that invaded my dreams and would always remind me of Castle. It calmed me down and made the hair on the back of my neck stand up at the same time.

"Kate, please. Look at me," he pleaded. I continued my staring contest with the floor. I had tried my hardest to rebuild the walls around me, and I knew that as soon as I looked at him, I would lose it all.

"I need you to know that even though this case is your life, I can't stand by and watch you throw your life away," he reached forward and let his fingers gently run along my cheek, before lifting my chin so that I was forced to make eye contact with him.

His eyes were their normal bright blue, but they glimmered with something darker. Something that was completely territorial and yet terrified at the same time.

"I'm never going to leave you in this alone Kate, I'm always going to stand by you while you fight this. But I know that if you get behind the wrong end of a gun, I won't ever recover from that. I'd rather take the bullet for you than live on knowing I could have done something to prevent it. But I don't want to put Mother or Alexis through that."

His hand sought mine and he gripped it hard.

"I don't want to, but I would. I would take that bullet for you in a second."

My heart was pounding in my chest, my eyes glimmering with unshed tears. For this man to put his family through something like that terrified me. His family meant the world to him, and for him to offer to take a bullet to save me...

"Castle...I..." My throat choked up with emotion as I struggled to find the words. A single tear broke free and made its way down my cheek.

He wiped it away gently, letting his warm palm rest on my cheek. I leant into his caress, covering his hand with my own as more tears slid down my face.

"Just promise me Kate, promise me that you won't let it get that far. Whoever these guys are, they mean business. It would break me to see you consumed by this case. But I'm here to fight it with you."

I let out an audible sob as the walls I had so carefully built around me fell to pieces. I felt my body cave inwards, and I grabbed hold of Castle's jacket to stop myself from falling.

The air left my lungs as he pulled me into his arms, holding me against his chest. His hands gently rubbed my back as I inhaled deeply, breathing in his smell and reveling in his warmth.

Castle's cheek was warm against my temple, and I felt his breath flutter my hair slightly. His stubble was slightly coarse.

We stood for what seemed like forever, fitting together like pieces of a puzzle. Then I felt him stir. He moved slightly, letting his forehead rest against mine. Our eyes met, and something sparkled in his eyes as he almost desperately searched mine.

My hands began to cramp from grasping his jacket so hard, so I gently spread them flat against his chest. He felt so wonderfully warm beneath my fingers, and as I looked back at his eyes, I felt his warm breath dance across my lips.

Suddenly the air between us became electric. His arms were still wrapped around me, pressing me to him. I felt my lips part as my breathing picked up pace.

His eyes glittered with longing and desire, stirring something deep inside me. Each shallow breath I took pressed my chest against his and I wondered if he could feel how fast my heart was beating.

Castle pressed his fingers harder into my lower back, causing a slight hitch in my breath.

"Kate," he growled; his voice so low and husky that my knees instantly went weak.

I felt a low moan rumble in my chest and I prayed that he hadn't heard it. I knew he had heard when his fingers bit sharply into my skin and he pulled me flush against him as his eyes flicked shut with a low growl.

His lips were mere centimeters from mine, and the tension between us was so powerful that it nearly dropped me to the floor.

Then everything changed when his eyes flicked open and his piercing, smoldering blue gaze met mine.

Our lips collided together as I pulled him as close as I could by his jacket. I moaned as he nipped my lip, and our tongues met in a passionate frenzy of teeth and tongues, fighting for dominance yet conveying the years of sexual tension, missed opportunities and wild, unspoken emotion.

I slipped arms around his neck so that I could wind my fingers through his hair. His hands travelled lower, his fingers pressed into my lower back as he began to walk me back. My back hit the counter and he stopped, pressing his entire body against mine.

I moaned again into his kiss as I felt his desire pressing against me through his jeans.

"God Kate," he growled in that guttural tone, "I need you to tell me if this isn't what you want. Because if we don't stop now, I don't think I'll be able to. But I won't push you."

As he spoke, he ran his fingers through my hair, letting his gaze wander up and down my face, searching my eyes.

I grabbed his jacket again and pulled him in for a kiss, hooking my leg around his hip. He was pressed against my core, and I gasped into the kiss as I ground against him.

He broke the kiss again.

"No Kate, I need to know." His eyes were smoldering. "Please."

"I've waited long enough Castle, please, don't stop now." I whispered breathlessly, raking my fingers down his shirt.

He kissed me again fiercely, sliding his hands down my back and ass to my thigh, before hooking my other leg around his hips, supporting me in his arms. He put me down on the edge of the bench top, which was a little too tall. He pushed up hard against me and his belt buckle pressed straight into my core, making me bite back a moan as he slid his tongue along my jaw and down my neck.

I pushed his jacket off of his shoulders and he released me for a moment so it could fall to the floor with a slight puff of air.

He wrapped himself around me again as I ran my fingers along his shoulders and down his back, delighting in the sounds he made.

I grabbed the hem of his shirt and tugged, and he helped me pull it off, letting that fall to the floor too.

I ground myself into his belt buckle, feeling the heat pooling inside my belly. As he covered my neck and collarbone with nips and kisses, he slid his hands up my shirt. His warm hands came into contact with my stomach and I felt goosebumps ripple across my flesh.

Gently he began to pull my shirt up and over my head, taking care not to be too rough. When it too had fallen to the floor, he took a moment to sweep his gaze across my body.

"Kate, God, you're beautiful. Really." He mumbled, kissing his way down my neck and along my chest, running his tongue along my cleavage. He slipped his hands under my plain black bra, grazing my already hard nipples with his slightly rough fingers.

My eyes flickered shut and I bit back a more vocal moan. Suddenly a thought occurred to me.

"Castle. God Castle, Martha and Alexis. We can't do this here." I mumbled as he unclasped my bra with a deft flick of the wrist. He tweaked my nipple before taking it into his mouth. The words left my mouth completely as I groaned.

"Castle, I'm not a quiet lover." I whispered frantically, hoping to get his attention.

His eyes instantly met mine, shimmering and dark with lust and arousal. In a second he had slipped his hands under my ass and lifted me. I wrapped my arms around his neck as he carried me to his office.

Once inside he turned and pressed my back against the door, pushing me against it to close it with a soft bang. Our lips met again, the passion doubled now that we were safely behind closed doors.

He turned me around again and walked over to his desk, which was littered with paper and notepads, pens and books. He set me down on the edge and leant over. In one fluid motion he swept everything off of the desk on to the floor. The desk was at a much better height, and his hardness pressed straight against my core.

As he kissed me, he ran his hands over my breasts, gently flicking and teasing my nipples. I let my fingers run down his chest to his buckle, undoing it quickly and pushing his pants off of his hips and to the floor.

I gasped as his bulge stood out prominently from his blue boxers, feeling the liquid pool in my abdomen. I ran a single shaking finger along it and watched as he yelped and jerked his hips forward into me.

I grinned wickedly and gently stroked him, earning deep, guttural moans that vibrated through his chest.

He moaned and grabbed my hands, wrapping them around my neck. I began to laugh.

"Kate if you want me to last, don't do that," he growled, gently nipping my earlobe.

The laughter died in my throat as he slipped his hands down my bare stomach to my pants. He made short work of them, and I lifted my hips to allow him to pull them down. He ran a finger along my panties, making me shudder and bite back a groan.

"Please Castle, don't tease me." I mumbled as he drew maddeningly slow patterns along me, making my hips jerk forward.

He grinned and hooked a finger under the elastic of my undies, pulling them down in one motion. He drank in the sight of me, my legs parted for him, revealing everything. Strangely enough, I didn't feel vulnerable. I felt...invigorated.

He crouched down in front of me and blew across me. I yelped, knotting my fingers through his hair.

And when he ran his tongue along me for the first time, I let out a strangled cry, wrapping my legs around his shoulders and holding him close as he began to work his tongue on me.

He brought me deliciously close to the edge, humming against me as I gripped him with my legs.

Finally, when I realized that I couldn't last much longer, I pulled him up so that he was standing in front of me again. As he kissed me I could taste myself on his lips and tongue, and he hungrily consumed my mouth. He ran a finger over me, testing to see how ready I was. I quivered under his touch.

I pushed his underwear to the floor and looked down to admire him. I groaned as I saw his erect member, running a hand along him and watching his reactions.

"I'm clean, and on the pill." I whispered, not sure if I would be able to stop in time to actively find a condom.

"Good, me too." He growled and with that, he slid into me. I cried out; he was hot and swollen and hard and exquisite. He moaned loudly into my ear before biting my neck hard.

He gave me time to adjust to him before sliding out again. We both drew shaky shallow breaths before he started a slow, steady rhythm. I met his thrusts with a jerk of my hips, pushing him inside as far as I could. We were both panting, covered in a layer of sweat that made our bodies slide together lusciously.

He slipped a finger between us and began to rub my clit, making my gasps and cries louder and more desperate.

I felt myself begin to tense, my walls begin to clench around him and I knew I was close. My head fell back as I panted.

"That's it Kate, I know you're close. Please, come for me. Let go," he whispered gently into my ear, his voice rough and breathless with arousal, "it's okay, I'm here. Just let go."

His words, his touch and the way he filled me so fully finally pushed me over the edge. My entire body tensed and then began to shudder, my orgasm ripping through me as I began to scream out his name.

He stopped my screams with his mouth, kissing me as best he could as my orgasm pushed him into his own. He grunted as he pushed into me, his thrusts becoming erratic as he finally spilled into me. He continued as long as he could before he became limp. The tremors continued to rack my body as I came down.

Castle kissed me and soothed me, whispering worship as he covered my sweaty body with gentle kisses and caresses as he brought me down.

When coherent thought returned to me I opened my eyes and found him watching me. I raised a shaky hand and brushed a hair out of his eyes with a smile on my face.

"Rick, take me to bed," I whispered gently, kissing him softly and sleepily.

"My pleasure," he returned, kissing me back and pushing the hair from my face.

And with that, he took my hand and led me to his bedroom, where I curled up into his dark blue sheets and into his warm arms and fell into a tired yet blissful slumber.

The following morning, we both woke early to a call from Esposito. I smiled sleepily at Castle before grabbing a shirt from his drawer and pulling it on.

Suddenly I became painfully aware that we had left our clothes in the kitchen. I glanced at the clock. 7:00.

"Castle, please tell me your mother and your daughter aren't early risers." I said quietly, feeling the panic rise in my chest.

Castle's expression turned from confusion to shock to horror in a matter of seconds.

"Mother might be, but maybe not, hold on, I'll check." He said in a blur, beginning to panic as we both realized that my little visit may have already been discovered.

He ran to the door, pulling on a robe. I followed silently, and listened desperately as he made his way down stairs.

"Ah. Mother. Good morning." Castle's voice was a mixture of apprehension and terror, but he did his best to remain casual.

"Yes, it is a good morning I'm sure." Martha sounded normal, and I almost breathed a sigh of relief. And then...

"I assume you're looking for these?"

I gulped as I heard Castle stutter. I felt the flush creep into my face as I realized she'd found our clothes. Mind you, it wouldn't have been hard, I mused silently. We did leave them strewn around the kitchen.

"Mind you, I don't know why Detective Beckett won't just come down and fetch them herself, I don't bite."

My heart stopped. My face was burning and I was painfully aware that I was wearing only a pair of his shorts and his top. Martha knew. My mind was a blur of emotion. My first instinct was to run. Anywhere. As long as it was away from her. And to do it soon.

"Wh-what makes you think Kate's here?" Castle stammered, tripping over his words.

"Well, how do I put this subtly? You weren't...darling, you weren't particularly quiet last night. Detective Beckett's the only person I know who calls you 'Castle'. And, I would recognize her clothing anywhere."

The memory of me screaming out as I came flashed through my mind. I suddenly felt extremely ill, and I began to back away to run to his bathroom and throw up.

"Detective, I know you're there, and I know you're listening, so you may as well come on down."

I froze on the spot, torn between climbing into a cupboard and not moving for the rest of my life and jumping out of his apartment window.

I swallowed hard and smoothed down my hair as best I could, painfully aware that I had no bra, no panties and no dignity left.

And I began to creep down the stairs to face the music.