When Beckett arrived at the precinct in the morning, she was pleasantly surprised when she found a coffee sitting on her table with a note.

Good morning Detective Beckett xx

So, the note didn't say much, but it was still sweet. She knew it could only have come from one person. Castle. And she had asked him to keep it professional at work, so it made sense that he hadn't written more.

Kate picked up the coffee to take a sip and almost burnt her tongue. The coffee was still extremely hot which meant Castle must have only just left it, and he was probably still in the building.

She thought back to the night before and the message he had sent her. He had a surprise for her. Looking around her desk she could see there was nothing other than the coffee sitting there, and surely the coffee wasn't the surprise. If it was, Castle had no idea what a real surprise was, Kate had thought.

It suddenly hit her that maybe he was waiting somewhere ready to jump out at her, and as funny as that may have seemed to him, she was not going to find that funny at all, not in her place of work.

Ryan and Esposito had not arrived yet, so she was unable to ask them if they knew where he was. With paperwork being the only thing waiting for her at her desk she decided to take a couple of minutes to look around. The first place she decided to look was break room, but she didn't make it that far before she found where Castle was.

Captain Montgomery was in his office and he and Castle appeared to be having a very serious conversation. His door was closed, so she couldn't go in, all she could do was wait for them to come out and then she would ask Castle what it was about. She hoped he hadn't gotten himself in trouble.

After a few minutes sitting at her desk, the captain called her into his office with himself and Castle.

"Oh, and now he's getting me involved. What could he possibly have done?" she thought to herself. She suddenly thought that maybe his surprise was that he was taking her away from work for the day, and he had been arranging details with the captain. Surely, he wouldn't do that would he?

Kate made her way into the office and stood in front of the captains desk while he made his way around to the other side and sat in his chair. Castle was sitting in another chair and had a smug look on his face. Something was going on, and she was desperate to know what it was.

"Detective Beckett," Montgomery started, "It seems Castle here is enjoying working with the medical examiner and the NYPD so much that he wants to get some further research done."

"Sir?" Kate questioned, unsure where he was going with this. She looked over to Castle, who was still sitting there silently but now he looked like he was concentrating on watching her, and then she looked back at the captain.

"Castle is going to continue his research with us, starting next week. He will be following you on a few cases to get a feel for the NYPD and how we work."

"Sir, you can't be serious. He's a civilian."

"Sorry Kate, we've discussed it, I've spoken to those above me and they are all happy for this to happen, including the mayor. They say the NYPD can always do with some more positive publicity, and well what better way than this."

"Until he gets shot or worse, killed. That's not going to be good publicity, you want to be the precinct that allows the famous writer to get shot?" she snapped.

Beckett was angry, and that was not the reaction Castle had expected. He thought about talking to her about it first, but decided that he would surprise her. It seems his surprise was more of a surprise for him than her. The way she was talking to the captain was almost like she had completely forgotten that he was even in the room. A part of him wanted to back out of the room and pretend he was never there, but that would probably make things worse. He could at least try and get Beckett to calm down.

"Well, you'll just have to make sure that doesn't happen then Beckett."

"Sir…"

Castle took the opportunity to stand beside Beckett and placed his hand on her shoulder.

"Hey, I wont allow myself to get shot, you wont allow it, I trust you," he said softly.

"Castle," she pushed his hand away. "Don't"

Captain Montgomery started making his way towards the door opening it for the two to leave. "Well, the decision has been made. Beckett, I suggest you get out there and get that paperwork finished before another body drops. Castle, I will see you on Monday."

Beckett huffed and walked out. Castle took a deep breath then followed her out. He had barely made it a few steps out of the office when Beckett grabbed his arm and pulled him into the break room. He stood there watching her as she closed the door and the blinds and then turned back to him with a look on her face that made Castle realise he really had made a huge mistake.

"Kate…" he started, reaching out for her shoulders again, hoping to calm her down.

"Don't Kate me, Castle" she said through her gritted teeth while once again pushing his hands away from her. "I can't believe you did this, behind my back."

"Beckett, I'm sorry. It was meant to be a surprise. I thought you'd enjoy having me around a bit more."

"This is my job. I can't have you here distra… getting in my way."

"That's why you're angry? You're worried that I'm going to distract you?"

"No, I'm worried that you are going to prevent me from doing my job. I'm worried you are going to do something stupid. I'm worried you're going to get shot, stabbed, run over, I don't know. I'm worried you're going to get killed." As she spoke the anger had started to fade and Castle could sense that there was an amount of concern there, she really was worried about him.

"Beckett," he took a step closer, "I promise, I will do only as I'm told, so I wont get hurt. I trust that you wont let me get hurt. And if I don't get in the way, if I don't do what I'm told, I give you permission to spank me."

He just wanted to see Kate smile again, and was hoping the joke would lighten the mood, but it seemed he was full of wrong decisions because the look on her face was not the one he wanted to see, the worry was gone and the anger was back again.

"See, that's just it Castle. You don't take this seriously enough. This isn't a joke. My job is serious. These are real people that have been murdered and it's my job to find the sons of bitches that do these things so I can bring some sort of closure to their families. You…. You are just here for a bit of fun." She turned and started walking towards the door, she couldn't deal with this right now, she had to get out of there, she had a job to get back to.

Before she got to the door Castle stopped her, grabbing her hand and turning her towards him.

"I don't know what else to say other than I'm sorry. I didn't think. Yes, I should have asked first, but I didn't and I'm sorry," he said walking closer to her again, not letting go of her hand.

She pulled her hand from his turned and opened the door that was behind her. "Castle, I think you should go."

"Beckett, I swear, I didn't mean to step on your toes. I wanted to surprise you. I wanted to spend more time with you. I thought I could be helpful."

"Just go!" she said and walked out the door before him, making her way towards the bathroom. The last thing she wanted was for Castle to see the tears that were threatening to fall down her face. She loved having him in her world, but this was too much. She couldn't have him in her work place. Some days it was hard enough to keep herself safe without having to worry about another person, a person she cared about, aperson that she was growing closer to every day.

"Kate? Please?" Castle called out to her.

"Castle. No!" she screamed and walked into the bathroom.

He stood outside the bathroom unsure whether he should just go in there after her, but decided to give her some time.

"I'll go talk to the captain. I'll tell him I'll stick with Lanie for a while longer, and if you really don't want me here, then I'll respect that," he said, hoping she could hear from where she was in the bathroom. He would let her calm down and talk to her later.

Kate leaned her back against the wall in the bathroom and just let the tears fall.

You know, I actually enjoyed writing that scene. Shocking. Let's hope they can sort things out.