Title: Don't Mess with Castle

By: Greygoose70

So far it had been a frustrating week. They had caught a case on Tuesday and here it was 5 PM Friday so Castle decided to come up to the gym and work off some of his hatred and frustration on the bags. So who was it he hated and who was he frustrated with you ask; well he has developed an overwhelming hatred for one male robbery detective and was utterly frustrated with one female homicide detective.

And why is your next query; maybe it's because he knows who the killer is but every time he approached the two detectives to give his input 'detective wise ass' from robbery would just shut him down with an insult or derogatory remark while 'detective goo-goo eyes' from homicide just gave him an eye roll and said nothing.

As he entered the gym Castle removed is coat and button-down shirt, placing them on the bench, then kicked off his shoes and headed over to the big bag. After a few warm-up exercises he started with some easy punches to get a feel for the bag. Just as he began to increase the force of his punches the gym door swung open and a male voice shouted out.

"Castle! What the hell you doing here?" It was none other than 'detective wise-ass'. "This gym is for NYPD personnel only."

"Just working off some pent up frustration." Castle answered, while continuing to punch the bag. The last thing he wanted was to get into an altercation with the detective.

"Castle, Tom's right. I think you should leave. Tom and I want to workout and we don't really need or want an audience" voiced Detective Beckett. She knew Castle would follow her lead and do as she asked. She also was aware of the animosity Castle seemed to have towards Tom and if they were to get into a scuffle he would not fair very well.

Castle gave the bag one last aggressive punch then turned and headed to the bench to retrieve his stuff. As he passed by the two detectives he heard Detective Demming mutter. "Good boy, do as your master says."

Castle stopped, turned, looked Demming right in the eyes saying; "What's your problem Demming? What the hell is you want? To show me up in front of your girlfriend, prove that you're the better man. What is it?"

"Castle, don't." Beckett said.

Turning his head to look at Beckett he replied, "It's okay Beckett. If that's what he wants then I'm more than willing to oblige him."

"Ooh good," cooed Deming. "Lets get it on then."

"You want to warm up first?" Castle asked.

"Nah, I'm good." Came Demming's reply as he headed for the center of the mat, Castle following behind him. "This is going to fun." He said laughingly while attempting an 'Ali shuffle.

Castle took his defensive stance, waiting for Demming to make the first move, which he did, moving in quickly throwing a right jab at Castle's midsection. Castle moved slightly to his left avoiding the punch while at the same time grabbing Demming's wrist with both of his, in an over/under fashion, and twisted, throwing Demming to the mat.

Demming did a quick roll-out and leaped to his feet coming at Castle again this time with a right leg forward kick which Castle swiped away while moving in and swinging his arm, clothesline style, across Demming's chest, again sending him to the mat. Again Demming did a quick roll-out and got to his feet this time facing Castle more cautiously.

Beckett could hardly believe what she was seeing. Twice Tom had came at Castle and twice Castle, with lightning fast moves had sent him to the mat. These moves by Castle were ones she had never seen before, they were not part of any martial arts defense she knew about. And the speed with which Castle moved. WOW! Unbelievable.

Castle waited cautiously for Demming's next attack, he didn't have to wait long.

Doing a little bopping and weaving Demming threw a right hook. Castle snatched the attempt with one hand while grabbing him at the elbow spun and arm slammed him into the mat. Seeing Demming getting to his feet slowly Castle performed a quick spin as he dropped to the mat swinging his arm out catching Demming ankle sending him toppling down again.

Demming scrambled up coming at Castle swinging wildly. Castle knew it was time to put an end to this. Blocking Demming's furious attempts until he seen his opening Castle stepped in close and slammed Demming in the chest with the heel of his hand then quickly dropped into a semi squat and with his left leg spun sweeping Demming's legs out from under him causing him to fall flat on his back.

Standing over him watching as Demming laid there gasping he told him "Just breathe Demming, just breathe. I didn't hit you hard enough to break anything." He then headed over to the bench to retrieve his coat and shirt and put on his shoes.

"Where did you learn to fight like that?" Asked Beckett as Castle was slipping on his shoes.

"Research. And now if you'll excuse me I'm going to see if Ryan and Esposito have returned with your murder suspect."

"Wait! What suspect?"

"The one you would have known about earlier had you taken the time to listen what I had to say instead of letting your boyfriend there, nodding his head at Demming, insult and degrade me." Then picking up his shirt and coat he headed out the door.

Beckett stood there momentarily then glancing over where Demming lay, still on his back, and seeing that he was starting to breathe easier she ran to catch up with Castle. He was just stepping on to the Homicide floor when she caught up with him. "Who is this suspect Castle and how do you know he's our killer?"

"Her Detective, Her. Your killer is a woman." And just as they rounded the corner they saw Detectives Ryan and Esposito stepping off the elevator with their suspect, one Debra Blessingham.

"Her. Mrs. Blessingham, that's your suspect. She has an alibi Castle. She was at the Carson's party. Other guests there recall seeing her."

"Aah yes my dear detective and according to your notes she arrived at 8 PM, was remembered being seen around 9:30 and again around 11, then at midnight when she left and Lanie places the time of death between 10 and midnight."

"So when did she have time to kill him oh wise one." Beckett retorted.

"Follow me." Castle replied heading for Esposito's desk. Once getting there he picked up a file and opened it showing Beckett a picture.

"So what is this?" She asked.

"This detective shows our suspect pulling into a parking garage that just happens to be across the street from where the Carson's held there party. You'll notice the date and time stamp as Tuesday at 11 AM." Picking up the next picture he continued. "Here she exits the garage on foot where she gets into a taxi that took her home. We checked with the cab company to find out her destination. She arrived at the party by taxi, the doorman remembered her." Continuing on he produced another picture. "Here we see her leaving the garage at 9:45 PM Tuesday night and returning at 10:50 PM. And then here she is pulling out of the parking garage at 12:02 AM."

"So how'd she get away from the party without being seen?"

"There's an exit door at the end of the hall back by the restrooms. All she had to do was jam the door to keep it from closing completely then come back in the same way."

"How did you figure all this out, Castle?"

'I just tried to figure out how I would do it so I had Ryan get street cam footage from the area plus any from the parking garage."

"And when did you do all this?"

"We got the street cam footage last night after you had left with your boyfriend, but we weren't sure until we able to view the garage footage this morning. After we put it all together I gave it to Esposito to give to you. He told me I should since it was my theory but every time I tried your boyfriend just shut me down basically telling me to get lost and you were never alone long enough where I could at least give you the folder so in the end just gave up, put it back on Espo's desk figuring he would see it and confront you."

"Oh god, I'm sorry Castle. I..."

"For what Beckett," he sounded angry now. "For ignoring me? For letting Demming degrade me?" For not listening to what I have to say? You've never not listened Beckett, you may have called my theories crazy, silly, sometimes even stupid, but you have never, ever not listened! That tells me that you, for whatever reason, either lost or never had any respect for me." Castle then began making his way toward the elevator.

"Castle wait." Beckett called out.

Without even turning around Castle responded loud enough for all to hear, "No Beckett, I'm done. Good-bye." And then he was gone.

The precinct suddenly got very quiet, Beckett could feel the eyes of everyone there upon her. "Okay." she said, "the show's over, you can go back to what you were doing." But nobody moved, everybody just kept staring. Beginning to feel self conscious she headed back up to the gym's locker room to change her clothes where she ran into Tom who was just coming out.

"Hey, I was just coming to look for you. What do say we get out of here and go grab some dinner?" He asked. "Once your changed of course."

"No Tom. I think you should go back to robbery where you belong and stay away from homicide."

"What are you saying, Kate? I thought we made a great team plus we get along great. I'd like for us to be more."

"First of all its Detective Beckett to you, second 'getting along' means you treat all members of my team with respect and listen to what they have to say especially when it has to do with the case. And finally there is no we, you are not part of my team and a couple of luncheons and a Chinese delivery dinner does not make an us. Kapeche."

"You mean Castle? He's not even a cop, just your tag-along puppy. He doesn't deserve any respect." And that's when he felt it. The solid punch to his left cheek that had him staggering backwards.

"You don't talk that way about my partner." Beckett shouted after punching him, thankful that her hands were still wrapped. "Are you stupid? Didn't you learn anything from your encounter with him? He threw you around like a bag of potatoes and then incapacitated you with a single blow that I'm sure could have broken your breastbone if he had wanted it to."

"So he has some hand-to-hand skills, big deal." Demming replied while holding his cheek.

"He has more than that. I watched him rapid fire three rounds in the ten ring, dead center, that you could cover with a half dollar. I'd say there's a lot more to Castle than either of us know about. Now I have to change and you have to get back to robbery. We'll call if you're needed but don't hold your breath waiting." Saying that last part as she pushed open the door and entered the locker room.

Less than an hour later Beckett sat at her desk contemplating the events that had occurred over the evening. Her boys had gotten a confession from Mrs. Blessingham and were now at their desks completing the paperwork. All thanks to Castle. She had basically little, no not true, she had nothing to do with the apprehension of their killer all because she was too rapt up in establishing a relationship with Tom. She let him push Castle aside debasing him, humiliating him and she did nothing to stop him. No wonder Castle was upset with her. Just then she heard her name being called.

"Detective Beckett, my office please," Captain Montgomery shouted from his doorway.

'Oh, oh that doesn't sound good' she thought rising up and heading for the Captains office.

"Close the door detective and take a seat," Montgomery ordered once Beckett had entered.

Beckett closed the door then took a chair in front of the Captains desk. "What do you need sir?" she asked once seated.

"First, can you tell me why I saw Detective Demming leaving here earlier holding his left cheek?"

"Cause I slugged him sir," Beckett replied.

"Why?" Montgomery asked.

"Cause he was making insulting and disrespectful comments about Castle."

"Okay, then why did I just get off the phone with Castle, him informing me that he would no longer be shadowing you."

"Because I fucked everything up, Roy," she said barely above a whisper as she lower her head and stared at the floor.

"Tell me everything, Kate." It was no longer Detective or Beckett it was Kate, friend and mentee.

"God Roy, I don't even know where to start."

"Well why not start with the case."

Kate related to him the details of the David Blessingham murder case, how Castle had solved it, how Castle had the evidence earlier in the day but every time he tried to present it to her she ignored him or agreed with Demming when he dismissed Castle telling him they didn't need any of his crazy theories.

"Go on" Montgomery said.

"After Castle filled me in on the case I tried to apologize, that's when he laid into me. How I ignored him, how I let Demming defile him even going as far to say I never respected him. I tried get him to stay so we could talk but he said 'no, we're done and then goodbye'."

By the time she finished she was trying desperately to hold back the tears forming in her eyes. "What am going to do?" She asked sniffling. "God I've made such a mess of things."

Roy reached across his desk handing her some tissues he said. "So tell me what happened after Castle left."

Taking the tissues and composing herself Kate continued. "I went back upstairs to change. Demming was just coming out, he approached me and asked me out to dinner. I told him 'no' that he needed to go back to robbery where he belonged that homicide nor I needed him. That's when he began his disrespectful tirade against Castle. So I slugged him. Although I thought he would have gained some respect for Castle after the beating Castle gave him."

"What beating? I need to hear about this." Roy said.

Kate let out chuckle. "When Demming and I got to the gym Castle was there working out on the he heavy bag. Demming told to leave the gym was for NYPD people only. I kind of agreed telling Castle we didn't need him as an audience. As Castle passed us on his way out Demming said "good boy, listen to your master'. Castle then basically challenged Demming. I tell you Roy I've never seen anything like it. Castle tossed Demming around like a rag doll finished him with a pop to the chest then swept his legs out from under him sending him to the mat gasping for breath. Castle was so smooth, so quick, no wasted movement. He just waited for Demming to come at him and countered everything Demming threw at him. Anyway afterwards I asked Castle where he learned to fight like that he just told me 'research'."

"Kate, you've read Castle's books, correct."

"Yes," she responded.

"And which one is your favorite?"

"The Derek Storm series. Why?"

"Because that series is based in part on Castle's own exploit's."

"Storm was ex-Delta force. Are you say so was Castle?"

"No but Castle is ex-Marine Corp, Security Forces Regiment. He was part of their Fleet Anti-Terrorist Security Team and Recapture Tactics Team. Part of his training included CQB, Close Quarter Battle, part of which included the takedown and securing of an enemy combatant as quickly as possible including extermination, if necessary."

All Kate could say was "Wow, I had no idea."

"And you weren't suppose to," Roy replied. "Castle never wanted his past known but since he won't be following you around anymore I don't suppose it matters."

"No Roy" Kate voiced loudly. "This is my fault and I intend to find Castle and fix it." She then rose from her chair and headed for the door.

"He's at the Old Haunt," Roy was able to tell her before she was gone.

Beckett left the precinct, hailed a cab, gave the driver the address to the Old Haunt, sat back and thought about how she was going to get Castle to forgive her and continue to be her partner. Partner. That had a nice ring to it, she has never had a real partner since she became detective. Kate was so engrossed in her thoughts that she hadn't realized the cab had stopped and reached her destination.

Beckett exited the cab, paid the driver, went down the steps that lead to the entry of Castle's bar and went in. As she passed the bar she noticed Jerry was on duty. "Hey Jerry why are you working tonight. I thought George worked the Friday evening shift?"

"He called in sick; so what are you drinking tonight."

"Scotch, neat and make it a double," she figured she would need some liquid courage when she faced Castle. "Where's the boss," she asked as Jerry poured her drink.

"Down stairs but he asked not to be disturbed."

"To bad" Beckett replied picking up her drink and heading for the secret stairwell.

Castle sat at his desk sipping on a glass of scotch while going over the bar receipts from the last couple of days. The Old Haunt has been doing real well since he purchased it, actually starting to show a profit. His musing was interrupted upon hearing the clip-clop of footsteps coming from the stairwell. He knew who it was, knew the sound of those shoes anywhere… Beckett. What the hell is she doing here,

Beckett had no sooner descended the last step when she heard Castle say "What do you want detective?"

Moving forward until she stood directly across of him she began, speaking calmly. "I would like for you to listen what I have to say, without interruption, and if by the time I'm done I haven't convinced you to come back and be my partner then I'll leave and you'll never have to see me again."

"Okay detective, go ahead," Castle said.

Beckett took a deep breath let it out and started. "I suppose I should begin by saying I'm sorry but I know it isn't or wouldn't be enough. My actions these past couple of weeks have been anything but professional. I let the feelings I was developing for Tom interfere with my judgement. I should have seen it from the beginning, the snide remarks between the two of you, the one up-man-ship, in a way it made me giddy watching your and his interactions. But then I somehow began agreeing more with him when he disagreed with your input or calling your theories asinine, ultimately just keeping quiet. After your scolding, after you left, I went back upstairs where I ran into Tom. He asked me out to dinner, I told him no. Told him to go back to robbery, stay away from homicide and stay away from me that there is no us. He started berating you again so I slugged him, told him there was more to you than meets the eye."

"Wait, you slugged him?"

"Yeah, I did. I've been blind Castle, blind to what was right in front of me, blind to everything you have done for me. You bringing me my favorite coffee every morning, you seeing that I'm fed regularly, you putting up 100K to catch my mothers killer, you letting me stay at your loft until I found a new apartment, you whose saved my life more these last two years than anyone else."

"Kate…"

"Please Castle let me finish."

"Okay."

"I was scared Castle, scared of the feelings I was having for you. Maybe that's why I started up with Demming, he was safe, wouldn't push. But you…you've learned more about me than than anyone. Damn it Castle. I'm not doing this very well so I'm just gonna say it. I think I"m falling in love with you."

Castle was out of his chair and had her wrapped in his arms in a heartbeat. Kate nestled her head on his shoulder (with her 4 inch heels she was almost as tall as him) sobbing. "I'm sorry Castle, so-so sorry, I've been a fool, I've been…"

"Not a fool Kate, just human and I forgive you, for everything. I have to because I've been falling in love with you also."

"You have," she said as she lifted her head from his shoulder her face millimeters from his.

"How could I not Kate, you are the most extraordinary woman I have ever met." He then leaned in and kissed her.

Kate's heart began beating wildly upon hearing Castle say he was falling in love with her too. She vaguely remembers her response, but she's facing him and he's calling her extraordinary …and wait, he's kissing me. He's kissing me and I'm responding and it feels oh so good. His lips are soft, pliable and demanding against mine, his tongue licking my bottom lip and now he's forcing it between my lips wanting me to open up for him, so I do. His tongue dives in, searching for mine and when he finds it I let out a moan. This is without a doubt the best kiss I ever had and I wish it could go on forever but the need for oxygen has become all to apparent so regretfully I break away.

"Wow! That was…"

"Amazing," they both say at the same time, both then laughing realizing how in sync they always are.

Castle takes her hand leading her over to the leather sofa where he sits down pulling her with him. Kate kicks off her shoes and lays down putting her head in Castle's lap, he begins softly stroking her arm with one hand while his other hand gently massages her scalp. They are silent but it is not uncomfortable.

"I was jealous, hurt, disgusted, mad," he finally said. "Full of rage. I needed relief so I went to the precinct gym to work it off. Usually I would just go to the gym at my building but I wanted to be at the precinct when our suspect was brought in.

"You have a gym at the loft; how often do you workout?" Kate asked remembering how he looked in his t-shirt earlier.

"Every day I try to get at least a 15 minute workout."

"Castle."

"Hmm"

"Why haven't you ever mentioned that you're a former marine?"

"Montgomery told you," said more as a statement than a question.

"Yes he did."

"I guess because if I did I think everyone at the precinct would have treated me differently and I didn't want that. I just wanted to be Richard Castle, writer."

"Don't forget nine year old and playboy," Kate interjected humorously.

"Oh my dear detective, playboy Castle fell by the wayside the minute he meet you." Castle then bend down and captured her lips in another toe curling kiss.

"You're really good at this," Kate said breathlessly after they separated.

"What, kissing?"

"Yeah."

"Only with you Kate. Only with you."

Kate reached up to pull him down for another kiss just as the intercom blared 'Boss the rest of your party is here'. Kate sat up swinging her leg over so she straddled him. "What party?" she asked.

"Just a little 'closing the case party', Kate."

"So who all is coming?" she whispered into his ear.

"The usual Lanie, Espo, Ryan who's bringing Jenny, Montgomery and probably half the Homicide department...and you of course."

"I don't remember getting an invite," then pecking him in the cheek.

"You're with me now you don't need an invite."

"You're right, I am with you," she said placing her lips to his in another passion filled kiss. God she could get used to this, kissing him, she thought.

Pulling away, reluctantly and out of breath Castle said, "Whatta you say we go up and join the party."

"Okaaaay, even though I"d rather stay here and make out."

"Me too," he replied giving her a chaste kiss.

Kate removed herself from Castle's lap, put on her shoes, straightened her clothes, ran her fingers through her hair, grabbed Castle's hand pulling him up from the couch and lead them up the stairs where they joined their 12th precinct family for food and drinks.

Later that evening when Castle took her home, standing in front of her door he wrapped her in his arms and kissed her. A kiss that told her he loved her, that he would always be there for her. Always. Leaning back looking into her eyes, seeing the the love she had for him in them and giving her on last gentle kiss he told her, "until tomorrow, Kate."

THE END