This one-shot piece is my take on what should have occurred somewhere at the end of "In the belly if the beast", episode 17 of season 6 of Castle. I felt that Beckett had been selfish in her decision to go undercover and she should have faced the consequences. Castle and she need to have a talk.

I hope you all enjoy what is written below!

Friendly Greetings,

Thomatshu

EDIT:

A lot of you all don't seem to get the situation and context of this part. Blaming Castle that he is too hard, shouldn't give ultimatums or yell.
The thing is that Castle is a passionate man about the people he loves. For example he tortured a guy when Alexis was kidnapped. On top of that it was a long day with no sleep where he had to wait helplessly to see if his fiancee would ever return alive to him. He is upset because he have to find out what is going on from someone else because Beckett didn't tell him what she was going to do.

This means one upset Castle. A Castle that would do things different than when he isn't broken by fear for Kate's life.
After situations as stressful as he encountered that day, we all do things sometimes we wish we hadn't.

For the ultimatum part: that's the way he gets Beckett to move forward. He did it at the end of season 4, which resulted in them getting together. He did it at the end of season 5 (arguably), which let them to be engaged. And here he does it to keep her safe.

To the reviewer who said she isn't selfish. You have to look at it from perspectives. From the perspective of society she is selfless, putting her life in danger for the greater good. But from Castles perspective she is indeed selfish. She goes undercover, something you never know if you are coming back alive from, in a drug cartel of which they basically know nothing. No information on who she impersonates and no information on the cartel. Basically she goes in blind. Did she think about Castle when she made her decision? Maybe, maybe not. She calls him after she made her decision but doesn't tell him anything. If you are going to do something like that, wouldn't a discussion with your significant other be important?

From a review:
'He respects her too much and if you had seen the episode closely, you would have noticed Beckett told Castle that he was with her though out and the last scene showed and as Marlowe said, Beckett chose Castle by taking his hand.. It showed Beckett has let her obsession with her mothers' case go and for her now Castle is one who matters the most. No one else just Castle.'

So if a guy thinks about my wife while cheating on her with someone else it's okay? Don't worry honey, I was thinking about you the whole time!
In my opinion she should have thought about him before she decided to put her life on the line for a case she had nothing to do with.

I got accused of being a Beckett hater. I'm not. But I see the flaws in the character. Like I see the flaws in Castle. Like I see the flaws in Alexis. I'm not blind to a characters shortcomings. Does this mean I hate a character. No!

Do I find their relationship unhealthy one-sided? Yes. As far as I have seen it's a lot of Castle pushing and giving, not always getting the same effort from Beckett. But that could be because not their whole relationship is shown in the show.

Someone mentioned some of the atrocious episodes near season 5s end. They where so out of characters from all characters that I wonder if the writers had even seen the show. So I'm reluctant to take it as evidence for one thing or another.

They were in the break room of the precinct. Just the two of them. It was the first time since they got Kate out of the woods that they were alone. Castle had pulled her in a bone-crushing hug, pressing kisses in her hair. Once they had disentangled themselves, Rick had pushed her on the sofa. Sitting down next to her and had taken her hands in his. Looking in her eyes, seriousness on his face.

"Kate, I know you don't want me to tell you what you can or cannot do." Castle started. "I know you are a strong and independent woman and I respect that. God I respect that about you. You don't need a man to do the thinking for you. That's why I never tried to tell you to do something, never tried to forbid you doing something. I don't want to. I never needed to. But I have to go against my principles here. What happened here today cannot happen again. Ever. I can't lose you, Kate. And especially not to something like this. I know you don't want to hear this but I'm going to say it anyway. Kate, I don't want you to ever go undercover again. Preferable never and at least not when we don't have everything in control ourselves."

Kate couldn't believe what she heard. She pulled her hands from him and stood. Anger radiating from her body.

"You are right, Castle! I don't need someone to think for me. I can make my own decisions." Beckett yelled at Castle. "If they ask me to do an undercover operation I can agree if I want to. And I damn well will in the future. They needed me. They needed me to take down that drugs cartel."

Castle flew from the sofa. Kate never saw him as furious as in that moment.

"You have a hero-complex, Kate! You think it is your job to correct every misdoing. To bring justice to every evil-doer. But this was! Not! Your! Fight! You could have said no and no one would have blamed you. Maybe there was no one else but they would have found another way to catch the bad-guys. But you said yes. You called me and didn't even tell me what you were going to do! I had to discover that you didn't respond to any of my calls, to my texts, to my voice-mails, emails. I called Ryan and Esposito, they didn't call back. If I hadn't come down here looking for you I would have never known. Where you even going to tell me if nothing had gone wrong?" Castle raised his voice,matching Kate's volume. If it was possible to have steam coming out of your ears it would have been the case for him.

"Tell me, did you even consider me in your decision? Did you think about how this could have affected me, how it could have affected our future?" Castle asked. "Did you think about you father? How he could have officers knocking on his door like all those years ago? What do you think he would have done when he lost you too? Lost you because you said yes instead of no?"

Kate felt like she had been dosed in ice-water again. All her anger vanished instantly, only to be replaced by an unimaginable amount of guilt. She felt the tears in her eyes.

But Castle continued mercilessly.

"You are not alone anymore, Kate. Those days are over. You are surrounded by people who love you. Me, your father, Alexis, mother, Lanie, Esposito and Ryan. Hell even Gates, although she won't show it. Yes, Kate, they all love you! Did you think about any of them? What it would mean to them to lose you?"

Kate needed to lessen her guilt. Defend herself in some way. She couldn't deal with the fact that he was right. What it would mean if he was right. She hated how weak her voice sounded. She had never felt so weak.

"It is my Job, Castle." She tried.

"No, damn it. It's not. I'm not speaking about you investigating a murder. That is your area. Your playground. You know how to read the situations and assess risks and dangers. But this undercover operation was thought up by a bunch of amateurs. I could have done a better job! They had no information. Not about the cartel and not about the woman you were to impersonate. They had no eyes in the meeting location. No backup. They send you in blindly. After all these months they were desperate for a breakthrough, throwing caution in the wind. And you were right there with them. Now what does that say?" he voiced his disagreement.

"I…" Kate was speechless. "We…"

Then Castle delivered his killing blow. He knew that he was probably way out of line here but he needed to get his message across.

"What if we had children together? Would you have done it then? Or would you have thought of them and said no? Would you have remembered how you felt the day they came knocking at your house, telling you your mother would never return. Or would you have felt the need to deliver justice and said yes? Please tell me, because I don't know anymore." Castle confessed his doubts.

Kate felt like she had been kicked in the gut. She couldn't hold back the tears, which had been threatening to fall, any longer. Did the man she loved really think that low of her?

But then again, hadn't she given him reason to? Her decisions to agree with the mission had been on the spot. Captain Gates had tried to dissuade her from doing it. She had offered to take any heat if she had said no. But Kate had said yes. She thought about castle. And about his family. About her father. About the boys. She hadn't at the time. They needed her to catch bad guys and she had answered the call. She now saw how selfish she had been.

"I told you before, Kate. I'm not planning on sticking around to see you get killed. And that is what is going to happen with undercover missions like this one. I know your job puts you sometimes in dangerous situations and I have accepted that because I trust you to know what you are doing. But in situations like this you don't get to have any influence on your odds of survival." Castle said, calming down and moving to create more distance between them.

Kate feared what was coming next. He was pulling away. He was going to leave her behind. He was going to pull the plug on their relationship. Give up on her.

"I hope you understand that I'm just trying to protect myself and my family from getting hurt like that." He continued.

"No, please, Castle, Rick. Don't do this." Kate pleaded. She couldn't lose him. Losing him would destroy her. After all they had been through he was a vital part of her.

"I love you, Kate. But I'm prepared to lose you over this because if you get killed and I didn't try everything it would destroy me. That's why I'm giving you an ultimatum. So think carefully about your answer because once given it is final and you don't get to change it again." Rick said. Kate could see how much it hurt him to speak these words.

"Either you choose the people who love you and you will never do something like this ever again. Or you decide that you can't promise me that and I will walk out this precinct and you will never see me again. Your choice."

Kate didn't need to think about it. She launched forwards and pressed her lips on his, her arms around his neck. Her body pressed against his. She felt his warmth seep into her body. She knew that she never could give this up. They were two parts that made a whole.

When they pulled apart for air she voiced her decision. "I choose you, Rick."

"Good." He answered, wiping away some of her tears with his thumb. "Because I don't know what I would have done if you said otherwise."

He pulled her back in. Now his turn to initiate a breath-taking kiss.

And there we are. I hope you guys and girls enjoyed reading my take on what should have occurred. Should you find any grammatical mistakes, please let me know so I can fix them.